Ford 8N Hydraulic Raises on it's own and sticks up

WarnerT

Member
I recently bought a 1949 8N that hadn"t been run in a year, or so I was told. After changing the plugs and cleaning out the carb I got it fired up but the 3 point arms immediately raised. They reached the top height and refused to go down by using the control. With the clutch in, two big guys could slowly push down the arms but obviously they weren"t falling with gravity.

I read it could be a stuck relieve valve or exhaust valve so we opened the inspection plate and tried to move what I thought was the relief valve rod. It didn"t seem to help but I"m not sure I found the right rod. There was too much fluid as a lot of it ran out through the bottom bolt hole and it appeared to be dirty but I"m not sure what it"s supposed to look like.

I parked the tractor in the barn (with arms raised) but control lever in down position. In a couple hours I came back out and the arms were down on their own. My first thought is to replace all the fluid but I"d rather not spend $80 to do that if that"s not the issue.

Any help is greatly appreciated. I"m quite new to this and I"m doing a lot more reading than manual labor at this point.
 
When the lift arms raised all the way up, reach in the inspection port & push the control rod to the rear. (that's the rod that runs from the top cover to the pump:

If the lift arms drop, you found the problem: a dirty pump.

I agree that just changing the fluid won't get you much.

For info on changing the hydraulic fluid, check out tips 3 & 4 at the link below.

There are two ways to clean the pump; the “quick clean” that gets a lot of the sludge out of it, & the right way that gets all of it, including the hard packed crud in the pump base.

For the quick clean, after you get the old fluid drained out (overnight is best) remove both inspection plates & start pulling the sludge in the pump base out by hand. Then, get a couple of gallons of kerosene or diesel fuel & pour it into the pump base. Catch it in a bucket & reuse it. (Some folks use a hand garden sprayer.) Flush the pump base out 5 or 6 times. Do not start the engine to run the kerosene through the pump; kerosene and diesel fuel do not have sufficient lubrication properties for a 60 year old hydraulic pump designed to be immersed in 90w gear oil. Some folks say it’s ok to start the engine, engage the pump for a minute or two, then turn the engine off. Your call on that one.

This 'quick-clean' is not as effective as dropping the pump & doing a full job. But if the choice is between doing nothing & the quick clean, spray it out. It worked for me for 3 years on my 1951 N. If you have the time, drop the pump; that is the right way to do it. I’ve done it both ways & don’t plan on doing the quick clean again. That’s because dropping the pump is not a big deal. If you have hard packed crud in the pump base, you are wasting your time w/ the "quick clean".

With all of the fluid drained out, block the front wheels & get the rear wheels up at least a foot. (you'll see why soon enough) Remove the 4 bolts holding the PTO shaft in & pull it to the rear & out of the tractor. Loosen all of the bolts. Remove all but 2 corner bolts. Then, carefully remove them. If you are lucky, the pump will drop free (and dump a pint or so of hydraulic fluid down your sleeves). If not, wrestle it free. The pump has 'ears' that fit into the housing; wiggle it a bit & it will drop free. If you have the rear tires a foot or more off of the ground, you will have enough arm room to hold the pump & lower it at the same time. Put it on your work bench & remove the safety valve (p/n 638) and the control arm lever (p/n 643) which will allow you to remove the intake & exhaust valves (p/n’s 640 & 698) Drop all of it in a bucket of diesel (or mineral spirits) or your parts washer & let it soak overnight. Once it has a good soaking, get it on the bench & start blowing it out w/ compressed air. Run cleaning fluid into the hydraulic discharge near the test port & make sure you get a good flow out the small hole in the side of the pump were the control valve fits. I don't see much need to pull it down any further just to clean it. But, I always replace the safety valve (p/n 638, about $25) Reinstalling the pump is harder than pulling it out because you have a gasket to worry about. (no sealer on the gasket) And, you will probably need a helper to guide the control rod into the pump rocker shaft unless you’ve done this 6 or 7 times before!

While you have the PTO shaft out, it would be a good time to replace the seal on it. It's got two spring clamps around it. Take your needle nose pliers & remove the one in the front. Then, hang the shaft & bearing housing in your vice & tap the butt end of the shaft; the bearing cap will come off (and the shaft will land on your foot). Then, remove the other spring clip from the other side of the bearing. At this point, remember that you never bought a seal driver & go get a BF socket & drive the seal out. If you have the new style seal, the white side goes out. (open side to the oil) Put some grease on it.

Contrary to conventional wisdom, not a lot of water gets in the oil from the shifter boot. Of course, if it's bad, replace it, but you get water from the draft control spring & the dipstick. But, most water is just a byproduct of the heating/cooling cycle of the oil.

You’ll need a pump gasket, safety valve, inspection plate gasket(s), PTO seal, PTO gasket, gasket sealer & 5 gallons of fluid to do all of the above.
cleanPump.jpg

75 Tips
 
Thanks for the quick response. I'm still not quite clear on the control rod, I found the rod connected to the control above, when I raised and lowered it and felt at the bottom it seemed to be a plunger going into and out of hole, is this what needs to be pushed to the rear? I tried this but it didn't seem to move to the rear, only vertically.

A second question, in your tips you seem to imply there is no difference between the Ambra fluid and the TSC GL1 fluid. I was under the impression that the Ambra fluid is the better option for year round use, but it is $80/5 gallon bucket at the nearest dealer, compared to roughly $50 for the TSC brand. I live in Michigan and plan to be plowing snow in potentially sub-zero temps so I'd be willing to spend the extra money if necessary.
 
that rod should move a rocker back and forth.. if it ai'nt moving.. your valving is stuck... could be gritty oil, especially if it looks dirty.

I think bruce was telling you you can use ambrag or gl1.. not that they were the same oil.

ambrag is the utf fluid meeting m2c134d specs.

gl 1-3 90w would have been close to what was originally shipped int he rear end.
 
So if the valve(s) are stuck should I clean it like Bruce said or do I need to replace those valves as well?

I meant that he implied they are functionally the same. I understand they are physically different, is there a consensus on if the GL1 works fine in cold weather?
 
I run GL-1 in my 8N year round in northwest Pennsylvania. In the winter, the hydraulics are pretty sluggish until I get her warmed up good.
 
" do I need to replace those valves as well?"

Probably not.

" GL1 works fine in cold weather? "

It does in VA! But 30* is cold around here.
75 Tips
 
I regularly plowed snow last winter with the 8N - near, at and below zero. I've used GL1 for years, the hydraulics were always slow in the winter till the system warmed up. The change to Ambra last fall fixed that. It dosen't seem to be as thick in the summer as GL1 though, got a few leaks here and there.
 
Update: I got down in there again last night and tried with all I could to get the exhaust or inlet valve to move by hand. No luck. The only thing I can figure is that the inlet valve is stuck open and the exhaust valve is stuck closed. Explaining why the lift raises as soon as you let go of the clutch with the PTO on, even if the control is in the down position, does this seem correct?

Secondly, I hooked up the back blade for weight and looked in with the PTO running. There's about a 1/4" stream of fluid running down from what I think is the ram cylinder. This explains why the arms fall down on their own.

So my thinking is that I have to fix that leak and I have to unstick or replace the two valves, and clean out everything, at a minimum. I think I have to concede to dropping the whole pump and cleaning it thoroughly and pulling the cylinder out also to repair that.

I'm assuming I should find out EVERYTHING that's wrong before I start taking stuff apart? I haven't drained any fluid to this point, so how much oil do I need in there to operate the pump and still be able to find additional leaks? As of now I'm still unable to see what's going on very well due to the fluid.
 
" I'm assuming I should find out EVERYTHING that's wrong before I start taking stuff apart?"

Your diagnostics are very good. You've done about all that can be done at this point: you need a top cover rebuild & a pump cleaning.

Check out the link below for a step-by-step on the top cover rebuild.

Plenty of us around here have done both, so just ask for help if something isn't clear.
Top Cover Post
 
Before taking everything apart - try this: go to the rear of the tractor and grab both lift arms at the end, you should be able to lift them manually just a hair higher than it is at now, then slam them down hard that fraction of an inch. May need to do it a few times. My '48 8N trailer queen does this on me from time to time and this fixes it every time.

Just something to try before getting your hands dirty.

Good luck,
Dan
 
Thank you, will you re-post the link?

I'm not sure I want to tackle this quite yet but I'll take a look at the steps. Anyone have any idea how much parts might run me for this mess? If I do it I'm going to do it right and spend the money to replace whatever I can to not have to do it again in the near future.
 
I am currently working on a 43 2Ns hydraulics. The gasket set and safety relief valve (I think was Bruce) mentioned along with a new NAA style piston ran about $80 w/shipping from this site.
There's a fellow on here that makes and sells a special fixturing jig that makes setting things up easier.
Since your gonna be in for a dime might as well be in for a dollar and have it fixed.
 
I can probably deal with $200+ to get the hydraulics fully functional.

Bruce, would you mind re-posting the link you mentioned above?
 

I have dropped/pulled quite a few pumps/lift covers... Its a one man show the only help needed is someone to hold my beer...

To do a good cleaning you will need to remove the sleeve the control valves operate in theirs nuttin to it measure and put them back like you found them...

I would run UTF myself were you are located you will not be disappointed...



http://forums.yesterdaystractors.com/viewtopic.php?t=348980&highlight=beer
 
My dad helped me dive into the hydraulics yesterday. Everything came apart without too much trouble. I wanted to get everything apart before ordering any parts since I wasn't sure what I needed. The issues were the lift automatically raising/refusing to go down and an obvious leak from the ram cylinder. There was a decent amount of sludge in the bottom but it didn't look like any water was in there. My wife happened to leave the camera in the barn so I took advantage of the opportunity.

Here are my discoveries:

Hydraulic pump. My original guess was that the control valve was stuck. Upon inspection I'm still not sure if it's toggling to the full extent that it's supposed to. I took two pics showing it's movement as far as I can push both sides by hand. Does this look correct?

mvphoto10210.jpg

mvphoto10211.jpg



Control arm. As you can see, it's pretty much bent. I read that I might be able to straighten it out but I haven't attempted it yet. I'm wondering if this was bent so far that it couldn't actuate the control valve properly?

mvphoto10212.jpg



Cylinder/piston. The piston is seriously scored... which solves the leak problem. Unfortunately there's also one significant score running lengthwise down the cylinder. The last pic shows it somewhat. It looks like a new cylinder is a decent chunk of change so I'm wondering if anyone on here has attempted to use an old, scored, cylinder with new piston and what the results were? I'm assuming I'd still have some leak down, but I'm okay with it to some extent. I hear that the new style piston with the neoprene washer seals better and might be enough to make it function adequately.

mvphoto10213.jpg

mvphoto10217.jpg

mvphoto10218.jpg
 
"Does this look correct?" Not in the least. The intake control valve is either stuck or has a broken spring behind it. It should not be resting in a position shown where just a bit protruding, but rather fully out of housing & hard against the rocker or using force against the rocker, pushed into the housing until the rocker touches the housing & valve fully inside housing. Control arm terribly bent, cylinder not looking reusable.
 
There are two causes for a control rod to bend.

It can be bent from a jack-leg adjustment method to avoid pulling the top cover, replacing the cam follower pin & adjusting the internal linkage.

The other & most common cause occurs when the control valve sticks. When that happens, the lift just keeps on raising up and pushing against the neutral dowel that the piston comes in contact when the lift is at the top of its travel. Pushing against the neutral dowel bends the control rod if the valve is stuck.

In addition to what JMOR said about your piston & intake control valve, I'd say your chances are better than even that you will need a new control rod. I've straightened a few, but the only one I tried to straighten that looked as bad as yours does broke......AFTER I reassembled everything & had used the tractor for a few hours.

What does your cam follower pin look like?
liftcover001.jpg

75 Tips
 
Not great news but to recap:

Pump - valve is clearly still stuck, I need to thoroughly clean it and try to remove that valve to get it unstuck? I should also replace the relieve valve? Anything else I should look for?

Control Rod - Attempt to straighten... but if it breaks I'm not seeing these readily available anywhere online, anyone know where I can find a replacement assuming I break it?

Bruce, if the cam follower pin is the one I think it is then it's worn pretty bad, I'll try to post a pic.

Cylinder/Piston - Replace piston, o-ring, leather or neoprene washer. Replace cylinder.

Question about Zane's jig/instructions.... mainly the instructions... would they help with what I'm doing and is it worth the $60 for a job like mine?
 
" Pump - valve is clearly still stuck, I need to thoroughly clean it and try to remove that valve to get it unstuck? "

Yes. Just drop the entire pump in your parts cleaner before you try to disassemble it.

" I should also replace the relieve valve? "

As I advised you earlier, yes.

" anyone know where I can find a replacement assuming I break it?"

Yes. These guys should be able to help you w/ used parts:

John Smith smith8NATatt.net

Rod Mondor fltractorATpeoplepc.com

Replace the AT in the address w/ @

" Cylinder/Piston - Replace piston, o-ring, leather or neoprene washer. Replace cylinder."

Yes. Use the neoprene washer.

" if the cam follower pin is the one I think it is then it's worn pretty bad"

Zane use to include one w/ his jig.

" would they help with what I'm doing and is it worth the $60 for a job like mine? "

Yes, get the jig. Because you will have 8+ hours of labor involved plus $200+ in parts.....and it will NOT work properly unless you correctly adjust the internal linkage.
75 Tips
 
How straight does the arm need to be? I straightened it quite a bit using 2x4s and pipe clamps. I'm pretty confident I didn't weaken it at all because the last thing I did was bend it past straight with all the force on the ball - left the clamp on for a couple hours and took it off. It actually sprang back a little to what it looks like in the pic. I'm not concerned about it breaking once re-installed.

Maybe the better question is, is there enough room in the adjustments using Zane's jig to compensate for the little bend that still exists?

Also posted a pic of the cam follower pin, I plan on replacing it with the one Zane sends.
mvphoto10244.jpg


mvphoto10245.jpg
 

I think the original pin is 3/4 X 3.123 a 5/16 dowel pin is 3.125 I use a 1" X 5/16 dowel pin .... Its a little hard to push in the original hole but doable... I spec what Zane sends is a standard 5/16 dowel pin... You should be able to make up for a site bend while you wait go ahead and get the yoke at the rear of the draft spring free, the first adjustment you make is draft if you skip it all the other adjustments are meaningless. Its all are nuttin !
 
Another question I had, should I be using gasket sealer on any of these gaskets as I re-assemble? I noticed that the sides that came off of the pump seemed to have some sealer on them but I'm not sure any of the others did.
 
" should I be using gasket sealer on any of these gaskets as I re-assemble? "

As I said on my first reply to you:

Reinstalling the pump is harder than pulling it out because you have a gasket to worry about. (no sealer on the gasket)

That applies to the top cover as well.
75 Tips
 
That applies to the top cover as well.

I was mainly asking about the gaskets on the two sides of the pump. I had to take it completely apart to get the valve unstuck.... and drive it out from the inside. It was actually getting bound up even after I cleaned it. I shined it up with some fine sandpaper and it's working smooth now.

I did go back and re-read your post but I got hung up at the bottom where you list gasket sealer with the materials needed.... which made me think of the gaskets in the pump... so that's my question.
 

The original gaskets stick so bad it would lead you to think a sealer was applied... I do apply a dab of 3M 8001 adhesive in several places on the pump were the pump to center housing goes just to keep it in place while I install the pump...

I also drive the bushings out the control valve and exhaust valve ride in and clean the junk out that's trapped behind the bushings...
Do you know what made the valve stick and why you had to polish it....
 
(quoted from post at 10:36:54 08/19/14)
I think the original pin is 3/4 X 3.123 a 5/16 dowel pin is 3.125 I use a 1" X 5/16 dowel pin .... Its a little hard to push in the original hole but doable... I spec what Zane sends is a standard 5/16 dowel pin... You should be able to make up for a site bend while you wait go ahead and get the yoke at the rear of the draft spring free, the first adjustment you make is draft if you skip it all the other adjustments are meaningless. Its all are nuttin !

Dowel pins are commonly available hardened and precision ground in "standard", "undersize" and "oversize" tolerance classes. McMaster lists the tolerances on their 5/16 pins as:

"standard" : .3125/.3127.
"undersize" : .3123/.3125
"oversize" : ..31259/.31262

In most applications requiring an interference fit dowel pin like the cam follower you would use a "standard" pin in a drilled undersize and reamed to finish size 5/16" hole.

TOH
 
(reply to post at 04:56:05 08/20/14)

I speck the heat got to me today along with a some add on's I got on my puter fudgen with facebook :(... I have measured a few original pins and they were .3123....
 
(quoted from post at 21:06:16 08/19/14)
(reply to post at 04:56:05 08/20/14)

I speck the heat got to me today along with a some add on's I got on my puter fudgen with facebook :(... I have measured a few original pins and they were .3123....
est long term research for PN 374072S is dia=0.309" X 7/8 length.
 
(quoted from post at 22:30:03 08/19/14)
(quoted from post at 21:06:16 08/19/14)
(reply to post at 04:56:05 08/20/14)

I speck the heat got to me today along with a some add on's I got on my puter fudgen with facebook :(... I have measured a few original pins and they were .3123....
est long term research for PN 374072S is dia=0.309" X 7/8 length.

If Zane still supplies the pin with his jig or if when he did...which exact pin size does he supply or get them from?
 
OP,
I had trouble posting links to the page. If you need a new cylinder I have a site for used stock if you want it and there are a number of sites for new stock. My reading says you might have to grind a little on new stock to make room for draft control linkage but I have not gotten there so far.
Thank You for posting on your journey.
Rick

Rick_Lind at comcast.net
 
(quoted from post at 18:43:30 08/19/14)
(quoted from post at 22:30:03 08/19/14)
(quoted from post at 21:06:16 08/19/14)
(reply to post at 04:56:05 08/20/14)

I speck the heat got to me today along with a some add on's I got on my puter fudgen with facebook :(... I have measured a few original pins and they were .3123....
est long term research for PN 374072S is dia=0.309" X 7/8 length.

If Zane still supplies the pin with his jig or if when he did...which exact pin size does he supply or get them from?

You should probably ask Zane if he wants to give you that information. I suspect he spent a lot of time and money to figure that out. Just sayin'.

I have recently bought a jig from him and it comes with the pin.
 
Do you know what made the valve stick and why you had to polish it....

I don't, there was a semi-circle stain on it from oil sitting on it since it's been stuck there for who knows how long. Like I said, even after I cleaned it up it still got bound up on the front corner, I only needed to polish that front corner to get it to slide smooth. It doesn't really make sense to me why it was only getting bound at that corner though, almost like it was little over sized from the beginning. Or maybe it just had a build up there that I had to remove. I got it fully cleaned up last night but I waited to put it all back together until I made sure about the sealer.

I'm hoping this is looks good??

mvphoto10264.jpg


mvphoto10265.jpg
 
I'm hoping this is looks good??

Wait a minute... I had to look back at my previous pics of the stuck valve... I have no idea how it got stuck where it did. Why would it have been stuck when it wasn't even in contact with the rocker lever?

The spring behind it was fine... it shot out like a missile when I pulled the cotter pin from behind.
 
(quoted from post at 21:30:03 08/19/14)
(quoted from post at 21:06:16 08/19/14)
(reply to post at 04:56:05 08/20/14)

I speck the heat got to me today along with a some add on's I got on my puter fudgen with facebook :(... I have measured a few original pins and they were .3123....
est long term research for PN 374072S is dia=0.309" X 7/8 length.

JMOR, I can't find that part number anywhere in my MPC???

Looks like it shows 73298-S18 which is listed in the numerical "standard parts" table for dowel pins as:

73298-S18 - 5/16 x 7/8

Not to mention .309 is bizarre - no fractional, letter, or metric equivalent either under or over in terms of a normal press fit.

Who conducted that research and how confident of it are you? I'd measure the one in my 8N but it isn't handy to get to at the moment ;-)

TOH
 
(quoted from post at 09:38:12 08/20/14)
(quoted from post at 21:30:03 08/19/14)
(quoted from post at 21:06:16 08/19/14)
(reply to post at 04:56:05 08/20/14)

I speck the heat got to me today along with a some add on's I got on my puter fudgen with facebook :(... I have measured a few original pins and they were .3123....
est long term research for PN 374072S is dia=0.309" X 7/8 length.

JMOR, I can't find that part number anywhere in my MPC???

Looks like it shows 73298-S18 which is listed in the numerical "standard parts" table for dowel pins as:

73298-S18 - 5/16 x 7/8

Not to mention .309 is bizarre - no fractional, letter, or metric equivalent either under or over in terms of a normal press fit.

Who conducted that research and how confident of it are you? I'd measure the one in my 8N but it isn't handy to get to at the moment ;-)

TOH
ell, Daniel, you know me, if I don't actually KNOW, I just pull something out of that place where the sun don't shine & post it as factual.
I have a hand written note (0.309") in my greasy FO-4 where I rebuilt my hyds about 2006 & probably measured it & found that I had nothing of the size in all my junk & went to Four Brothers Ford (local dealer) & bought #374072S. Might still have the old pin & if I run across it, will measure for you. Since you question, I went to the keyboard & what do you know, a couple of "trusted" sources show up!


http://www.yesterdaystractors.com/cgi-bin/viewit.cgi?bd=nboard&th=109032

http://www.yesterdaystractors.com/cgi-bin/viewit.cgi?bd=nboard&th=417127

http://www.yesterdaystractors.com/nboard/messages/508766.html
 
(quoted from post at 07:31:18 08/20/14)
Do you know what made the valve stick and why you had to polish it....

I don't, there was a semi-circle stain on it from oil sitting on it since it's been stuck there for who knows how long. Like I said, even after I cleaned it up it still got bound up on the front corner, I only needed to polish that front corner to get it to slide smooth. It doesn't really make sense to me why it was only getting bound at that corner though, almost like it was little over sized from the beginning. Or maybe it just had a build up there that I had to remove. I got it fully cleaned up last night but I waited to put it all back together until I made sure about the sealer.

I'm hoping this is looks good??

mvphoto10264.jpg


mvphoto10265.jpg
n the second picture if that's as far as the valve will go in you still have a problem. It should go in until the rocker arm contacts the housing.
 
In the second picture if that's as far as the valve will go in you still have a problem. It should go in until the rocker arm contacts the housing.

Thanks Carl, another thing I noticed, all the pictures I can find of other pumps show the exhaust side fully depressed when the toggle is at rest (without any finger pressure on either side). Currently, at rest mine sits like it is in the second pic. This is incorrect, also? It's as if the spring pressing the exhaust valve out is stronger than the spring pressing the intake valve out.

I almost took apart the exhaust valve but I was unclear how it comes out - there's no obvious pin holding it in there. Any tips?
 
(quoted from post at 10:37:51 08/20/14)
In the second picture if that's as far as the valve will go in you still have a problem. It should go in until the rocker arm contacts the housing.

Thanks Carl, another thing I noticed, all the pictures I can find of other pumps show the exhaust side fully depressed when the toggle is at rest (without any finger pressure on either side). Currently, at rest mine sits like it is in the second pic. This is incorrect, also? It's as if the spring pressing the exhaust valve out is stronger than the spring pressing the intake valve out.

I almost took apart the exhaust valve but I was unclear how it comes out - there's no obvious pin holding it in there. Any tips?
eed to get ex valve out & clean it up as it is still sticking. Spring inside it, not behind it. Nothing holds it in bore once linkage is disconnected.
 
I'm no expert on pumps only had one apart when I worked on mine. Best I remember the only thing holding that valve in is the rocker. Someone with more knowledge that me will know they helped me with my pump overhaul.Ok Jmor answered that while I was picking with one finger.
 
Thanks guys... I'll have to pull that exhaust valve out from the front somehow, hopefully it's not as stuck as the other one was. Glad I posted those pics and put some more thought into it... almost put it back together still stuck.
 
As Hobo stated in an earlier post the yoke on the draft control spring needs to come off as that's the first step when using Zanes jig. I had to soak mine for about a week with PB blast before it turned loose just a reminder if you haven't gotten it off already.
 
(quoted from post at 10:26:05 08/20/14)
(quoted from post at 09:38:12 08/20/14)
(quoted from post at 21:30:03 08/19/14)
(quoted from post at 21:06:16 08/19/14)
(reply to post at 04:56:05 08/20/14)

I speck the heat got to me today along with a some add on's I got on my puter fudgen with facebook :(... I have measured a few original pins and they were .3123....
est long term research for PN 374072S is dia=0.309" X 7/8 length.

JMOR, I can't find that part number anywhere in my MPC???

Looks like it shows 73298-S18 which is listed in the numerical "standard parts" table for dowel pins as:

73298-S18 - 5/16 x 7/8

Not to mention .309 is bizarre - no fractional, letter, or metric equivalent either under or over in terms of a normal press fit.

Who conducted that research and how confident of it are you? I'd measure the one in my 8N but it isn't handy to get to at the moment ;-)

TOH
ell, Daniel, you know me, if I don't actually KNOW, I just pull something out of that place where the sun don't shine & post it as factual.
I have a hand written note (0.309") in my greasy FO-4 where I rebuilt my hyds about 2006 & probably measured it & found that I had nothing of the size in all my junk & went to Four Brothers Ford (local dealer) & bought #374072S. Might still have the old pin & if I run across it, will measure for you. Since you question, I went to the keyboard & what do you know, a couple of "trusted" sources show up!


http://www.yesterdaystractors.com/cgi-bin/viewit.cgi?bd=nboard&th=109032

http://www.yesterdaystractors.com/cgi-bin/viewit.cgi?bd=nboard&th=417127

http://www.yesterdaystractors.com/nboard/messages/508766.html

Well you know me Jesse - I trust you like my brother and never doubted you for an instant ;-)

Pretty reliable "source" and totally unambiguous :lol: Just to "be sure" I checked and CNH does list that part number. Probably supercedes the one in they MPC. Why they would chose such a bizarre dimension for such a simple part still leaves my head spinning. But then I find that to be more and more the norm these days :roll:

TOH
 
(quoted from post at 21:06:02 08/20/14)
A 5/16 dowel will go in the hole... Done it a many a time...
.0035 is quite an interference fit, but I don't doubt you.........I have done a few serious interference fits in my lifetime, too. :wink:
 
(quoted from post at 19:16:46 08/20/14)
(quoted from post at 10:26:05 08/20/14)
(quoted from post at 09:38:12 08/20/14)
(quoted from post at 21:30:03 08/19/14)
(quoted from post at 21:06:16 08/19/14)
(reply to post at 04:56:05 08/20/14)

I speck the heat got to me today along with a some add on's I got on my puter fudgen with facebook :(... I have measured a few original pins and they were .3123....
est long term research for PN 374072S is dia=0.309" X 7/8 length.

JMOR, I can't find that part number anywhere in my MPC???

Looks like it shows 73298-S18 which is listed in the numerical "standard parts" table for dowel pins as:

73298-S18 - 5/16 x 7/8

Not to mention .309 is bizarre - no fractional, letter, or metric equivalent either under or over in terms of a normal press fit.

Who conducted that research and how confident of it are you? I'd measure the one in my 8N but it isn't handy to get to at the moment ;-)

TOH
ell, Daniel, you know me, if I don't actually KNOW, I just pull something out of that place where the sun don't shine & post it as factual.
I have a hand written note (0.309") in my greasy FO-4 where I rebuilt my hyds about 2006 & probably measured it & found that I had nothing of the size in all my junk & went to Four Brothers Ford (local dealer) & bought #374072S. Might still have the old pin & if I run across it, will measure for you. Since you question, I went to the keyboard & what do you know, a couple of "trusted" sources show up!


http://www.yesterdaystractors.com/cgi-bin/viewit.cgi?bd=nboard&th=109032

http://www.yesterdaystractors.com/cgi-bin/viewit.cgi?bd=nboard&th=417127

http://www.yesterdaystractors.com/nboard/messages/508766.html

Well you know me Jesse - I trust you like my brother and never doubted you for an instant ;-)

Pretty reliable "source" and totally unambiguous :lol: Just to "be sure" I checked and CNH does list that part number. Probably supercedes the one in they MPC. Why they would chose such a bizarre dimension for such a simple part still leaves my head spinning. But then I find that to be more and more the norm these days :roll:

TOH
ot a lot more bizarre than the threads on generator armature shafts?! Guess we had to be there?
 
(quoted from post at 17:17:47 08/20/14) As Hobo stated in an earlier post the yoke on the draft control spring needs to come off as that's the first step when using Zanes jig. I had to soak mine for about a week with PB blast before it turned loose just a reminder if you haven't gotten it off already.

I took the yoke/spring/plunger assembly off last night. One shot of PB and the yoke came off very easy using a breaker bar through the hole as leverage... seemed way too easy based on what I've read... We're talking about the same yoke, (#41) right?

mvphoto10288.jpg


I got the exhaust valve on the pump unstuck and the pump is all cleaned and reassembled except for the new safety valve which is on the way.

Once I got the control arm off last night I was able to straighten it further, so I'm satisfied with that. New cylinder/piston and rings are on the way.

I assume I can work on removing the cam follower pin but anything else I can do while I wait for zane's jig?
 
(quoted from post at 23:32:57 08/20/14)
(quoted from post at 21:06:02 08/20/14)
A 5/16 dowel will go in the hole... Done it a many a time...
.0035 is quite an interference fit, but I don't doubt you.........I have done a few serious interference fits in my lifetime, too. :wink:

If the diameter of the [u:8f636e5cbd]pin[/u:8f636e5cbd] is .309 the diameter of the hole is smaller and the interference is more like .005. That is a heavy press and you can probably get away with it on a stubby 5/16" x 7/8" pin but try it on one an inch or so longer and I am pretty sure you will have significant bending issues to contend with :roll:

The armature threads are bizarre but I understand (I think) the reasoning behind it. They had a factory equipped with imperial threading equipment manufacturing a shaft mount for a metric ball bearing. Putting an imperial thread on the end of a metric shaft was cheap and easy.

I can't fathom a reason for needing or wanting a non-standard size dowel pin. The reamer to make the hole is a simple/standard item. And the sharpening guys in the tool crib could care less whether the reamer is .3095 or .3075 - they just dial in the grinder. Making or contracting for a special size dowel pin is something altogether different and had to be an additional cost.

I guess we will never know unless someone can contact Mr. Peabody and his time machine :lol:

TOH
 

Never had a problem I use a 1" pin... I can not lay my hands on the pins I use at this moment I get them at a local Mill supply house...
 

We're talking about the same yoke, (#41) right?

That's it mine was rusted on solid thought it wasn't going to break loose.

I assume I can work on removing the cam follower pin but anything else I can do while I wait for zane's jig?

I used a short bolt, socket and a vise to press the pin out with a piece cheater pipe on the handle. I would clean the sump good while the pumps off and make sure all gasket surface are clean.
 
(quoted from post at 10:01:27 08/21/14)
Never had a problem I use a 1" pin... I can not lay my hands on the pins I use at this moment I get them at a local Mill supply house...

I'm sure they work fine. Maybe next time you replace one you could measure the hole just to satisfy my curiosity ridden cat ;-)

If I were in the area I'd drop by with my pin gage set. Absent that I believe you have a new toy in the shop and can turn up a plug gage that fits light thumb tight snug in the hole :idea: Then a micrometer measurement of the plug should give you the hole size accurate to within a thou or so.

TOH
 
That's it mine was rusted on solid thought it wasn't going to break loose.

I've been amazed at how little trouble I've had taking this tractor apart since I bought it. All the plugs/bolts/etc that were supposed to be difficult have been easy. Makes me think it's been stored inside its whole life... or most of this stuff has already been broken free recently.
 
Popped a original out the hole is .307... checked a few old pins .308,,, Installed a .312 X 1" dowel pin use a press it would be harder if you did not have a press....

The original came right out with a hammer and punch I spec the 312 would give a fight...

To keep the pin from wearing the ramp sideways a 1" pin will perform better...
 
I used a short bolt, socket and a vise to press the pin out with a piece cheater pipe on the handle.

I'm having a lot of trouble getting the pin out. I cant drive it out while it's attached to the top cover and I can't figure out how to get that piece off so I can put it in a vise. It's connected to the quadrant/control lever but I took out the 4 bolts on the plate and the one locknut on the end but it doesn't want to come apart. Are these threaded together somehow or are they just stuck?
 
54 comes out from the inside of the lift cover you are gonna have to take 55 off...

That's what I thought, but how does 55 come off? Is it threaded or just a seized/painted on there? I've got everything undone, hit it a couple times with a hammer and tried to pry it with a wrecking bar but it's not moving.
 

If it luminum heat it with a propane torch (don't melt it) use a couple screw drivers and pry it off... When its ready it will come...
 
Follow up:

I was able to the follower pin out with the help of another person, it came out with a hammer eventually.

It took me two tries to get the adjustments right, I screwed something up the first time and had to take the cover back off. I've got it all back together now and the hydraulics seem to work just as they should. The only issue is that there's a small leak from the pump gasket near where the tube runs the oil up to the top. Obviously that's where the most pressure is. I may regret not using any kind of sealer on the gasket right there, but for now I'm going to ignore it and keep an eye on the level.

Thanks for everyone that helped me on this. I didn't have much confidence when I started but now I feel like an expert, even though I'm probably not.
 

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