# TO30 hydraulics



## Boodog (3 mo ago)

Has anybody tried to replace hydraulic pump control vales with pump still in the tractor?
Have removed pump 3 times. Once to replace "o" rings after arms would not lift. Lasted about a year with being able to lift, powerful but jerky when fully up. Second time arms went down and would not raise - replaced "o" rings but lift was weak and only able to lift at half throttle, removed pump again and found "o" ring half out of pump - replaced with new and checked valve and rods. Reinstalled pump and again the arms lift at half throttle but will not lift when placed under load. Thinking this could be control valve but don't want to remove pump unless I have to.

Any thoughts/suggestions are appreciated.


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## Boodog (3 mo ago)

First line should be control valves vs vales.


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## FredM (Nov 18, 2015)

Boodog that sounds more like the seals on the ram piston have had it, what valves in the pump are you talking about, do you mean the spool valves in the hydraulic control valve?.

Do this, with no weight on the lower links, start tractor and raise the links to full height or to whatever height they will raise to and then stand on the ends, if the links sink down with your weight, then you can be 90% certain that the seals on the ram piston have had it.


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## Boodog (3 mo ago)

Sorry it took so long to reply but trying to read up on the ram piston removal/repair etc. 
The valves I replaced were the chamber valves. 
With a scraper blade and me at 220 lbs. on top it will raise the blade and me to full height but setting to at least half throttle. Less throttle and only lifts slowly and I can push lift arms down with blade attached.
Trying now to educate myself regarding the seal on the ram piston.

Thanks for your info. - if you have any more would gladly like to read it.


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## FredM (Nov 18, 2015)

If you were to raise the 3 point with the back blade mounted and then let it sit in the raised position, does the blade sink back to ground level with a sinking rate that can be seen with the eye?, this would then indicate the ram seal is suspect and also previously you said the 3 point jerks when raised, most times this is also an indication that the piston seal is faulty.

Do you have the manual covering this repair?.


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## Boodog (3 mo ago)

FredM said:


> If you were to raise the 3 point with the back blade mounted and then let it sit in the raised position, does the blade sink back to ground level with a sinking rate that can be seen with the eye?, this would then indicate the ram seal is suspect and also previously you said the 3 point jerks when raised, most times this is also an indication that the piston seal is faulty.
> 
> Do you have the manual covering this repair?.


I have a service manual but for the life of me I can't seem to find information specifying the piston seals. References to all other parts are listed. The illustrations are grainy and somewhat hard to see. I have found a listing for the seal on ebay but no other info. yet. Still looking though.


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## FredM (Nov 18, 2015)

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www.ntractorclub.com





I tried to attach to the forum page, but was told the PDF is too large, go to page 171 and this will give you measurements for ram cylinder and piston and rings.

I am sorry but the piston uses rings, not seals as in silicone type, so might pay to see if there is a trouble shooting section in the manual for leakdown.


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## Boodog (3 mo ago)

Thank you for this. Now I'll see how far I get. The photos/illustrations are much clearer than what I have been looking at.


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## Boodog (3 mo ago)

FredM as an update I have removed the piston and new rings are ordered and a new cylinder "o" ring has now been installed. I also ordered the hydraulic pump control valve and safety valve. Waing for these to arrive.
Any advice for ring orientation or any other advice before I reassemble?
Thanks


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## Busted Tractor (May 22, 2018)

Been working on masseys for years. When hitch works it is not the control valve. When the hitch is slow to raise especially if jerky the pistons are leaking past in the pump. Newer pumps has a piston ring to help seal them. May or may not be able to use them on the TO. Also jerky is usually caused by the outlet or inlet valves leaking. Most of these systems usually slowly leak down with the engine off but as I said slowly. If it leaks down rapidly check the orings on the standpipe first. Then the cylinder and the cover to cylinder. But before doing a lot of work take the RH side cover off and observe all for leaks, anything under oil you will notice oil swirling. Just don't stick you head or hand inside or close to the hole and blow the relief valve!


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## Boodog (3 mo ago)

Busted Tractor said:


> Been working on masseys for years. When hitch works it is not the control valve. When the hitch is slow to raise especially if jerky the pistons are leaking past in the pump. Newer pumps has a piston ring to help seal them. May or may not be able to use them on the TO. Also jerky is usually caused by the outlet or inlet valves leaking. Most of these systems usually slowly leak down with the engine off but as I said slowly. If it leaks down rapidly check the orings on the standpipe first. Then the cylinder and the cover to cylinder. But before doing a lot of work take the RH side cover off and observe all for leaks, anything under oil you will notice oil swirling. Just don't stick you head or hand inside or close to the hole and blow the relief valve!


[Are you referencing the high pressure tube. Not sure I understand the "standpipe" ? I'm using the to30 service manual as a guide.
I have replaced valves and "o" rings in the valve chambers. After that the lift arms would go up after that but, would be slow unless under half throttle any less than half throttle I could push them down. Still have hydraulic pump and hydraulic lift out of the tractor as I'm waiting on parts.

Thanks/QUOTE]


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## Busted Tractor (May 22, 2018)

Yes that the standpipe is what you refer to as the high pressure tube. 
From the description of the problem you were having it could be anything from relief valve, bad exhaust valves, the standpipe o rings, the o ring between cylinder, or cylinder piston rings 
The control valve probably is not the problem.
If the pistons of the pump were the problem everything you stated would be affected except the hitch would not be able to be pushed down.

www.agcopartsbooks.com Parts books for agco (Massey too)


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## Boodog (3 mo ago)

Thanks for the info.
Went to AGCO but cannot find listing for the standpipe or high pressure tube though. I'll keep looking.


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## Busted Tractor (May 22, 2018)

It is shown with the center housing.


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## Boodog (3 mo ago)

It sure is - found it

thanks


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## Boodog (3 mo ago)

Wanted to let you know I finally got it all back together and it works well. Wanted to let you know how much I appreciated your information. Replaced the ram piston rings, ram piston "o" ring, high pressure relief valve, new gaskets put it together and it all works as I think it should. 
I have been using it on the burn pile moving/pushing/lifting stumps, logs etc. 
Now I'll be ready for the snow when it comes.
Thanks to everybody who helped me out.


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