520 wont lift

[Dieselcowboy 210]

I put the tiller on my 96' 520 yesterday , everything was fine. Today I tilled and it lifted all the way up at first then next time less and less the next. It will raise if I help ever so slightly on the back of the tiller.  Fluid level is good. Trans works perfectly. Hyd lift just doesn't seem very strong. Any ideas?

[js5020 111]

Only thing that comes to mind is a blown piston packing and its leaking internally.

[Ed Kennell 35,741]

Will it stay up if you stand on it , or does it leak down ?

[Dieselcowboy 210]

It will stay up.

This tractor ran a 60" deck for the first 600hrs of its life if it makes any difference.

[Ed Kennell 35,741]

If it stays up with additional weight, it must not be leaking by the piston rod seal.  Must not be getting enough pressure from the pump.

[Dieselcowboy 210]

wonder if replacing the trans filter could help. it has a wh filter on it still. One side note which it has done since I've know this tractor is it squeals when it reaches its limit of travel on the cyl or comes up on resistance like it is doing now.

[Ed Kennell 35,741]

Sounds like new filter and oil are in order... maybe you'll get lucky.

[Dieselcowboy 210]

I've looked around on here for the cross on trans filter #'s Looks like a Napa 1410 for the eaton 1100 correct? 

[bmsgaffer 2,043]

You can order the original WH filter from toro still.

 

I will have to leave the filter number to the pros i think its either 1410 or 1420. one is a hydraulic filter one is an engine oil filter.

 

The squealing is form the bypass circuit on the valve under the dash. It releases oil back to the tank when the circuit reaches its maximum allowed pressure of 700 psi. You could have a problematic bypass circuit or the seals on your control valve could be shot. (the lever on the dash that does the raising and lowering).

 

I would look at that before a pump. The eaton manual also shows a way to put in a gauge and measure the pressure of the charge pump (lift) circuit.

[shorts 182]

Sure sounds like a low pressure problem, put a 1000 or larger psi guage in the pressure side of the hydraulic circuit, adjust the relief valve in the lift valve to 700 psi when the hydraulic cylinder is bottomed out in the lift mode.

[bmsgaffer 2,043]

I do believe the Eaton 1100 relief valves are not field adjustable. I dont know why, but it states in many manuals the sundstrands are, eatons are not.

[cheesegrader 433]

Transmission filter 

Toro 108335/79-5270

Wix 51410

NAPA 1410

[squonk 38,906]

I know you don't want to spend a lot if the pump is junk, but I would put Mobil 1 10w30 in it too

[Dieselcowboy 210]

I just changed oil and filter. it will lift if I rev the engine almost to full throttle. it didn't take near that much the other day. it still drives very responsively on the hydro forward and reverse.

[Dieselcowboy 210]

ok I gauged the charge pump just like the manual says to at the cyl using the down pressure side. it's right at 700 psi like it should be. hmmm. So it holds the tiller up when not running, the charge pressure is in limit. and it will raise very slowly at full throttle. I must be missing something.

Edited April 22, 2014 by Dieselcowboy

[squonk 38,906]

Maybe something with lift control valve?

[ericj 1,576]

if the tractor runs as it should and the lift does hold and don't drop i would have to say look at the control valve. i changed the oil and filter in my 416-H and my 520-H last fall. i had problems with both this winter, the tractor would move but not lift for a long time. basically till the trans started to warm up a little. i used the napa 1410 filter. a dealer told me that the napa filter is a finer screen ( more micron than oem ) and that could be my problem. it was just to cold snowy and nasty out to get them changed but it is on my to do list. the lifts work fine as long as its not so cold out. i say it probably only affected the lifts when temps were below 32° out or somewhere there about

 

 

 

eric j  

[Dieselcowboy 210]

I did use the Napa filter today. after the change I tilled the garden of course not lifting very well and at the end (warm) still not lifting. what is there to the control valve? can I do the work at home to it?

[Dieselcowboy 210]

I think you may on to something on the spool valve. I went and tried it again, when it hits any resistance or weight it starts doing the squealing thing. - by pass- so that would mean I need to do what with it?

[ericj 1,576]

rebuild it don't ask how i don't or replace it. i would think it is only o rings that would need replacing. i would think kelly or somebody on here would have a used one for sale

 

 

 

eric j 

[MalMac 1,328]

There really is not much to rebuilding them. Just about all that's in there is O rings. The worst part is getting the valve off the tractor. Once you have it apart inspection is the key. Look for any scoring on the spool or in the valve body itself. If there is sometime a very light emery cloth will take it out. If not you would be money ahead replacing it. Like I said getting the thing on and off the tractor is the worst part. There is also a rebuild manual available form Toro for Download. I have not checked it might even be here on RS.

[bmsgaffer 2,043]

If it starts squealing quickly, the system is either hitting 700psi too soon (clog, issues with lift cylinder or lift mechanism) or its bypassing too soon (bypass valve is not working correctly).

 

The bypass valve is not serviceable and will not be fixed if you rebuild the lift valve. (must be replaced)

 

I think there is a problem with the lift system because you did measure 700psi. (I would double check that number on the lift side since that is what you are having trouble with). If the bypass valve was failing, you would not see that pressure, it would be too low.

 

Here's my recommendation:

1. Remove all attachments
2. Disconnect the lift cylinder from the rock shaft and make sure is moves freely by hand
3. reconnect lift cylinder and cycle it up and down without attachments and see how it does
4. if all above look good, rebuild the lift valve. Its like $8 worth of parts from rcpw.com and there may be some issue where the full flow is not getting to the cylinder
5. If all the above look good, I would check for hydraulic hose issues or bad lift cylinder (last resort as this involves the most expensive fixes).

Some guys have had good luck taking the lift cylinder apart and bringing the o-rings to a hydraulic shop and getting replacements cheap. If you have to order the Toro kit for rebuilding the cylinder its like $60 from rcpw. Hydraulic hoses are pricey too.

[MalMac 1,328]

classic Kitchens did offer the cylinder rebuild kit for a lot less than Toro's kit. I don't know if they still do or not. Also they might have had the lift control valve kit also. Like said the if the by-pass is not working you need a different control valve. You also might check for debris blocking one of the lift cylinder lines. Sometimes old hydro lines deteriorate and can let pieces of hose go through the system. which may block the line and never even make it to the filter.

[bmsgaffer 2,043]

classic Kitchens did offer the cylinder rebuild kit for a lot less than Toro's kit. I don't know if they still do or not. Also they might have had the lift control valve kit also. Like said the if the by-pass is not working you need a different control valve. You also might check for debris blocking one of the lift cylinder lines. Sometimes old hydro lines deteriorate and can let pieces of hose go through the system. which may block the line and never even make it to the filter.

 

Unfortunately classic kitchens doesnt have any more of the cylinder kit, and I dont think their valve kit works on the newer valves (ie 520). But yea, old hoses could be the problem.

[shorts 182]

If the lift valve is not leaking to the atmosphere resealing it is just an exercise in futility, their are no soft seals or O-rings in the part of the valve that controls oil flow. the internal sealing is done with tight tolerances between the valve body and the spool valve, typically the spool will also have some labrinth seal grooves machined into the OD to also help control oil flow.  After the spool their should also be a relief valve cartridge to control the max pressure on the auxiliary/lift hydraulic system, it should not exceed the pressure developed by the transmission pump

 

try putting your pressure guage in the supply side of the aux/lift system and then bottom out the lift cyl and read the pressure