Hydraulic leak when PTO engaged

jjbath · Jun 26, 2009

My TC35 has a small hydraulic leak under the seat where the PTO engagement shaft goes. I can't tell exactly where it is yet but I'm hoping its a simple fix.

I purchased it used from a dealer with 1100 hours. I have put almost 30 hours on it so far and found no leaks. Then tonight I used the PTO to do some mowing and I noticed a little fluid under the seat. I've never seen any fluid there before. I assume that its only leaking when the PTO is engaged. I will know for sure when I get some time to play with it.

Does anyone know if this is a common problem? I'm looking to buy a repair manual but I haven't found one yet.

Thanks in advance for your help.

jjbath · Jun 28, 2009

I just pulled the PTO valvle off and replaced the o-rings. Hopefully that does the trick. The bolts were a little loose so I suspect that using the PTO lever allowed the vavle to move enough to allow a little dirt in and the o-rings lost their seal.

So far it looks good. I'll need to run it for a little while to know for sure.

It was a real pain removing the seat assembly by myself. Its alot heavier than it looks.

jjbath · Jun 29, 2009

Ok, it looks like its still leaking but not as bad as before. I suspect the o-rings I used aren't exactly correct. At leas I hope so otherwise I can't figure out why its leaking.

I looked on Partspring.com for the o-ring kit and that thing is ridiculously expensive. For 5 o-rings and 2 eclips they want $60. That is blantant price gouging. This whole kit shouldn't be more than $10 maybe $15 but $60 that really annoys me.

jjbath · Jul 1, 2009

No one has ever had the PTO valve leak before?

I don't know why its still leaking after I replaced the o-rings. The only possiblity is that the shaft seals are leaking too. I can't tell where the fluid is coming from but it sure looks like its leaking from under the valve.

jjbath · Jul 1, 2009

Here is an image of the valve (PTO control valve) I'm describing. Its under the seat.

I replaced the 3 o-rings (#13 in the diagram). I did not replace the 2 o-rings (#3 in the diagram) on the Spool (#2).

I got this image from www.messicks.com

thclimer · Jul 1, 2009

Fortunately for me I have never had any leaks from O-rings. However, I can understand with the extreme pressures created within a hydraulic system even a small discrepancy in O-ring sizes could result in a leak.

Did you keep the old O-rings, just wondering if you could take them somewhere to get an exact match?

jjbath · Jul 1, 2009

I have the old ones and I bought 2 400+ piece o-ring kits. 1 Metric and 1 SAE. I believe the o-rings are metric but I'm not 100% sure.

The leak isn't that bad and it only leaks after running it. While its running there are no leaks at all that I can see. You would expect it to leak under pressure but it doesn't. It must be a return line.

I'm going to take it all apart again over the weekend to see what I can find. Its not to hard to get off except for removing the seat.

thclimer · Jul 1, 2009

Wow, it doesn't leak under pressure, only when not running. That must be a clue to indicate something, maybe someone familiar with hydraulics would know what means. Sounds like you need a chain fall or hoist to lift that seat off. Hope you can find the problem.

jjbath · Jul 1, 2009

You actually don't need to remove the seat but I can't get the roll pin out of the pto lever with it on. If I had shorter punches it may work but mine are to long to fit under the seat and still be able to hit it with a hammer.

I'm planning on stopping tonight to see if I can find a set of short punches otherwise I will try making one.

Hooked_on_HP · Jul 1, 2009

All O rings are not the same. Not only are there sae and metric but they are made from different materials. A cheap buna o ring wont take the heat and pressure of a hyd. system for long. Partsspring and Messicks are usually cheaper than my local dealer
Bill