1872 Hydro Leak - Relief Valves

GWRdriver · Apr 30, 2008

After mowing for the first time with my new (to me) 1872 I came back a day later to discover it standing in a puddle of hydro oil. Long story short . . . . hydro oil is being forced out of the tops of the relief valves, otherwise things look OK. The valves on my 129, the pushbutton relief type, never leaked a drop in 35 years.

I recall seeing a thread a while back which addressed something about these valves (rebuilding, replacement, etc.) but can't find it. I don't want to start a new thread if this problem has already been covered somewhere.
Thanks,
Harry
Nashville

Update: Filter and oil are Cub and correct but I don't know how old the filter is. I pulled one valve and it looks clean, rings look OK, etc.

Bob_Bainbridge · Apr 30, 2008

A little dirt can cause the valves to leak. You can try flushing them with kerosene or a cleaning solvent while depressing the check valve. Blow them out with an air compressor if you have one. If all else fails they will have to be replaced.

Bob B.

OhioGuy · May 3, 2008

I have the same problem on one of two 1872's I own. I tried soaking them in mineral spirits and hitting them with compressed air, no change. I wanted to try swapping them wit the other 1872, just can't find the time.

The leaker gets parked outside, on the gravel!

Curt

GWRdriver · May 6, 2008

Curt,
Both of mine are leaking, just squirting a lot of oil out the top hole. I've got them soaking in solvent right now so I'll report my results when I have some to report. I'm told a company named Sauer-Danfoss makes these, anyone know their part number?

GWRdriver · May 12, 2008

I thought I'd follow up and post my experience with an attempt at cleaning the relief valves. I first removed (and discarded) the external O-rings and soaked the valves in regular gasoline for a couple of days. I then did a thorough wash-out in fresh mineral sprits and using a piece of .090"+/- drill rod to continually actuate the internal ball and plunger valves (from the bottom) I blew out the valve with 100psi air. I replaced the O-rings with new and installed the valves. In an hour of hard mowing this afternoon there wasn't a drop of a leak.

OhioGuy · May 17, 2008

Harry,
That's great news, I'll have to try your technique and see hope I get the same results.
Curt

GWRdriver · May 20, 2008

Curt,
A 2nd hard mowing has produced no leaks so I guess I'm good to go for a while. I don't think I made it clear that I spent some time actuating the valve plungers (with the rod) WHILE they were immersed in the gas and mineral spririts hoping to get as much cleaning action as possible. I didn't see any way to get at the insides of the valves with any effectiveness so some surface residue remained visible on the plungers.
Harry
Nashville Tn

OhioGuy · May 20, 2008

Thanks Harry,
That's the part I left out when I cleaned mine. I soaked them for a day or so, then just blew them out the best I could.

From what you said I'm thinking maybe a little time in the ultrasound cleaner at work might be in order, plus the valve actuation.

Thanks,
Curt

GWRdriver · May 31, 2008

Well my cleanout job didn't last. After another couple of hours an overflow began to appear and by the time another hour had passed they were worse than ever. Screwwit, I bought new ones.