Ford 8n hydraulic fluid

Stanley M

New User
Hi everyone I am new to this forum. Just bought a ford 8n tractor last week. Got it started and tried everything out. PTO worked and so did the lift, I did not have any attachments so I had my neighbor hold on to it and it picked him up around 180 lbs. I bought a mower and tried picking it up but it did not. In fact barely started to pick it up. Checked the fluids and found milky color. Tractor had been setting for about year or a bit longer. I know I need to change the hydraulic fluid so I am wondering how I could try and clean the system without before taking it apart. Also have 5 gallons of Royco 717 Hydraulic fluid which meets MIL-DTL-1711C and was wondering if I could use this? Any help is welcome as I do not want to use the tractor again until I address this issue.

Thanks
Stan,
 
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.
75 Tips
 
........ Checked the fluids and found milky color. Tractor had been setting for about year or a bit longer. ......

Thanks
Stan,

The lift arm rocker shaft goes through 2" id bushings . Most of the shafts I have removed lately are rusty and pitted on the top side . I feel this is a major source for water contamination on tractors that are parked outside .

When you change your oil , it would be helpful to park it undercover or tarp the rear end to avoid more contamination .
 
(quoted from post at 13:59:23 05/30/16) Hi everyone I am new to this forum. Just bought a ford 8n tractor last week. Got it started and tried everything out. PTO worked and so did the lift, I did not have any attachments so I had my neighbor hold on to it and it picked him up around 180 lbs. I bought a mower and tried picking it up but it did not. In fact barely started to pick it up. Checked the fluids and found milky color. Tractor had been setting for about year or a bit longer. I know I need to change the hydraulic fluid so I am wondering how I could try and clean the system without before taking it apart. Also have 5 gallons of Royco 717 Hydraulic fluid which meets MIL-DTL-1711C and was wondering if I could use this? Any help is welcome as I do not want to use the tractor again until I address this issue.

Thanks
Stan,

No - that is a pure hydraulic oil and not suitable for use in drive axles. Get yourself a Universal Tractor Transmission Fluid (UTTF).

TOH
 
Thanks everyone for the advise and helpful hints. I bought this tractor for about $1700.00, when I got the tractor started the lift worked great but as I mentioned before I did not have a big load on it. The guy I bought it from started to restore it but he just did some paint work, new muffler, steering wheel, and seat cushion. He told me it had been pared under a carport for about a year or a little longer so he bought a new battery and tune up kit. When I first checked the hydraulic fluid it was clear on the dip stick but I guess water was at the bottom. He did tell me that the all the hydraulics worked well when he parked it. I will try the quick clean first until summer is over then pull the pump and clean out everything as suggested. Once again thanks for all your help.

Stan
 
FORD TRACTOR MC 134D hydraulic oil is still sold at your local CNH [Case/New Holland] dealer now under the AMBRA brand. Not cheap, was about $50 a gallon last I looked. Your local TSC store [Tractor Supply] sells a product specifically labeled for old Ford tractors 39-53 much cheaper and seems to work OK.

134GEAR6.jpg

TSC13401.jpg

Tim *PloughNman* Daley(MI)
 
Alright gonna get some oil cause I pulled the plugs on the bottom and milky color. Thnaks again everyone for the visual on the fluid.
 

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