IH 1566 Air in Hydraulic Trans Oil

Working on MCV valve and pump replacement - second time doing the job - two weeks ago I lost (after the tractor sitting overnight)my steering, clutch, TA, and Brakes...

So I replaced the pump...just the pump - reassembled and nothing.

My flow control valve is fine - I did not read pressure - but my pressure switch, which shows 6V w tractor off, goes to zero volts at the lowest of RPMs (and I have some steering clutch and brake function) to 6V at any higher RMP when nothing works.

When I drained the fluid - it was draining full of air bubbles...so clearly I don't have pressure cause I'm sucking air from somewhere...

So Im doing a complete overhaul of the MCV...I've got it all apart, but not really seeing anything out of wack.... - some of the internal orings are pretty flat and seem to have microscopic cracking...but IDK how much that will affect total pressure loss.

Couple questions...I cannot find any plastic check valve and spring - there is a hole on the lower right that has no thru hole so I can't see how any fluid gets there to operate a check valve nor can I find it or part numbers on the case IH site.

Also - I can see three tubes that come into the the top of the mcv off the clutch housing and I cannot remove them...should I?

Lastly - the dump valve is operated by a lever at the clutch - It looks, by a picture in my manual that there is a spring that this bolt goes thru to work against the "pulling out action" of the dump valve - well that spring is NOT there and it also doesn't show up on the case IH site parts diag's...nor do allot of other springs I have that I know where they go...

So IDK - but its friday and I'd like to get parts...or order parts, if I'm needing them...

Any help would be great...

Oh and last Aug - I replaced all the filters and hyd fluid but I did not replace the filter O-ring even tho I bought one...manual said to replace it, if it was broken. Which is wasn't...

Any chance that is where I'm sucking air from? And wouldn't that have started right away vs after using the tractor for 50hrs?

3pt works fine - a hair slow and a minor leak down and PTO works fine.

The suction tube O ring could be bad. Add another 5 gallon of Hy Tran to cover the Oring with fiuld. The extra fuild won't hurt a thing and save a lot of labor trying to replace that o ring inside the rear end housing.

Gary

Yea - I had done that already...

It did not make a difference - the air is coming from somewhere else.

I'd love to hear from the The Tractor Vet again - I know he's probably busy - but I really think he could help me...

Tom all i can tell ya is what to look for but you do not have the stuff ya need to check everything . Just because you think everything LOOKS ok with out testind each and every spring for length aand test strength were shooten in the dark. You have no means to test pressure . You have not found the sump check plug or the little spring . I ca not come and look for myself as you are not close to me . Your really in over your head. Ya need someone there at the tractor that knows what he is doing. Before i turn a bolt i test first then decide what is needed . IF i am replacing a T/A then we do it all while i am in there . I do not want to hear well just do the T/a and nothing else , NO we are doing it all now as i don't want to hear OH this is not working now since you Put the T/A in or the main clutch is now sliping or now it will not steer . When i go into a MCV i will check the springs , i will replace each and every O/Ring and each and every Gskt. I was called out once to a guys place that just had and I H dealer do a T/A job on his 1066 and after only five hours it just Stopped moving . He called the dealer that did the work and they told him that it was not there T/A that failed and it was going to cost him to get it hauled in and if there T/A failed they would fix the T/A but nothing else. That is when i got called to see WHAT else failed as i was cheaper . What i found was that they never went into the MCV while it was in and with them pulling the MCV off one old o/ring between the firt plate along with the gskt. had blowen and they also did not replace any of the o/rings on the three tubes going from the MCV to the t/A and they also had let go . and this was done by and I H dealer . So some place along the line someone was there before you and there is something wrong and i can not see for myself . Just where in god's green earth are you located at anyway.

Thanks for weighing in...but I have some info for ya...I can't find the sump plug and spring causa it wasn't there. The prev owner had placed a steel plug in their...apparently after market...so I don't think I'm over my head (yet)...I had to drill a hole in the cylindrical plug and then put a screw in their and then pull it out. Then went to Case IH and bought the plug and spring.

As far as pressure - your right - I cant' measure exact pressure and not made of cash so I can't really go spend the 250.00 to 500.00 to get a guage capable of measuring 1900 psi...

But I can use my noggen and use the pressure guage that is there - as well as loosen the pressure plug test port and start the tractor and see if it squirts hyd fluid...and it does not - infact I can freely turn that plug at full throttle - You saw I removed the flow control valve by starting the engine and it spit out the valve.

So I don't really need any expensive equipment to know I have flow and no pressure...I got frothy tans fluid because the damn starter broke the same day the steering did - and now i can start the tractor to warm up the fluid vs draining it cold...which is how I knew it was full a air... so I got it all drained out and have napa premium ready to go back in.

As far as the mcv - i've got all the orings replaced - all new gaskets on all the layers and all springs except the two that require I remove pins - I tried but they didn't wanna come out easy so I left em - best I could do...I did check them and move them w a screw driver to see if I could hear if they were broke - and they were not.

I live in NW MO (64458) and just dropped 6500 into repairs on a JD 2555 and if I have to drive this to a tractor repair, well....I'll sell it first...I don't have the cash to keep spewing - I've dumped a boatload into equipment this year in repairs...probably close to 15K...

If we are beyond the simple fix possibilities - would just like to know...any thing simple comes to mind - would like to know that too...

Case does a really weak job on their shop drawings and even their online breakaway parts list is deficient in any sort of detail...

Anyhow thanks for weighing in but really...the plug wasn't there and now you know there is an aftermarket plug available...

Don't blame Case for anything,the drawings,tractor was all IHC 10-15 years before Case got involved.I doubt that the new co.changed any of the drawings.

Now is a heck of a time to have a problem with your tractor , as i was out in N/E Mo for 16 days helping a vary close old friend with her farm . I can tell ya this it is 623.4 miles from my drive to hers .I will be back out there for a day or so to get one of her tractors that is DEAD and bring it back here as i sold it to a good friend back here . And also to get the manure spreader that is going to another friend . So i will be back out there come spring to do more work around her farm . And this time i am going to take a longer stay . 16 days i hardly put a dent in what needs done. Waisted way tomuch time tryen to get her 4 wheeler to go . When i do come out i am going to just take it down to the dealer and tell him to call me when it runs.

Tom you NEED gauges to really check anything dealing with your hydraulics. I don't know who told you that a 2500 PSI gauge was $200. Here is a link to Bailey Hydraulic. You can buy a 0-3000 or 0-5000 PSI gauge for $13.

A couple of cheap gauges and a few fitting will not run you over $75. You will waste that much time/money in guessing what is wrong with it.

Also hydraulic oil that has been aerated is not bad. The air will come out of it just setting around. IF it has water in it then it would need to be heated to make it separate.

You can save your self some money just doing a few simple things.

1) Buy a IT service manual. They are not as good as a factory manual but they are better than trying it this way. THIS very site has them.

http://www.ytmag.com/IH202_6925.htm.

The cost is $29.95 + shipping. So maybe $40 tops.

2) Get a pressure gauge to check things out. Cost will be less than $20 with shipping.

So for less than $50-60 you can get a much better idea of how deep you problems are.

I will tell you this. A IH with hydraulic issues usually takes someone that understands there hydraulic system well to fix it correctly the first time. I have seen too many guys just throw money at them and never get them to work correctly. Even with all of the years I have worked on tractors I still get someone to help me on IH trouble shooting the hydraulics. If you have to hire some one good just to look at it to tell what to fix will be money well spent.
Bailey Hydraulic

Thanks a bunch for the tip on the guages...I will link right over to that and order those. Appreciate it...

I do have the I&T book for the tractor - its how I've gotten this far - wouldn't be confident to take apart the MCV without it - but the schematics there are still lacking....Like there is NO picture of the "important" dump valve - just a note showing gen location and guys hand in the way holding the dump valve with his fingers in the way of the valve...

Turns out - theres an aftermarket plug for that valve...who knew???

T