Hydraulic valve leaking (1641)

[cnysabo]

Hello Cub fans,
Today while starting up my 1641 I had a huge oil leak/gush. It was coming from the bottom (send?) line of the hydraulic control valve. So I took it apart and there was no O-ring on that line, though they were on the other lines. I figure it blew out somewhere yesterday while snowblowing. Anyway, I replaced all 4 O-rings and put the system back together. Then I tightened everything down and turned it on and fluid continued to come out of that spot. Right where the line mounts into the valve block. I checked for pin holes, for cracks, for flat spots on the hose or grit in the valve block... nothing. All seems in good shape right where it is leaking.

What is more is the system is passive from bottom to top (send to return?) when not engaging the lift or lower arm. Yet it doesn't leak on the top of the valve. Is it possible to have clog in the system and the weakest link is the bottom of the valve block? Or am I missing something obvious. I have never taken this stuff apart before today, but it's all pretty straightforward mechanical stuff it seems.

Any advice would be much appreciated. It has worked like a dream this year in removing snow, but I was wondering when a problem would stop the works... Thanks.

[darkminion_17]

did you check to see if the old O ring was still in the valve body?

[cnysabo]

Thanks for the reply. If the old O-ring is in the valve body, I don't know where. It is a clear hole straight through...

[ol'George]

Is the spool leaking or a fitting?
The spool has "o" ring seals go to partstree and look it up.
http://www.partstree.com/parts/?lc=c...&dn=0028050020

[Oak]

Here is a 3000 series valve, they look close but I'm not sure they are the same.
DSCN1422.jpg

They have two O rings on the spool as Ol'George said.
DSCN1424.jpg


On the 3K machines they use an O ring and a back up ring to seal but I don't see that on the parts breakdown for your machine. Maybe it would help, maybe not. The ring goes on the pressure side and the back up is away from the pressure.
DSCN1428.jpg


Here is what I ordered from McMaster Carr.
mcmaster.jpg

If you want to try, pm me your address and I will send you a couple of the rings for free.

Also, IIRC there is an external pressure relief valve on the HG hydros so that could also be a problem if it is missing or not working.

[cnysabo]

Thanks again for helping me out everyone. I suppose it could be coming from the spool. It can't hurt for me to disassemble it since I have it all out of the tractor. If it is I will be surprised because it certainly looks like it is leaking right out of the pressure/send line. Before writing this I tried to take it apart but I really can't seem to get the interior snap clamp out? Perhaps that requires a special tool? Anyway, I will see what I can do.
Thanks for the kind offer Oak. First I need to get the thing apart and then I will see where to proceed from there. thanks again.

[cnysabo]

I came across this thread which is exactly what I'm facing (though I searched before I began a new thread)...
http://www.onlycubcadets.net/forum/s...ad.php?t=21054
Looks like I may need to take to hose off and inspect a little more closely. Looking at it in place in the tractor shows it is in fine shape, but now I am doubting myself. I will post any finds/solutions.

[ol'George]

If the spool isn't leaking, leave it alone, as sometimes ya nick an "o" ring
sliding the spool into the housing.
Never worked on THAT spool, but most are similar.
Hope you find the line is split, and get it fixed easily.

[cnysabo]

Hello again. Good news.. kind of. After taking the line off and inspecting it, I could then see a hairline crack tucked under the collar of the line! I am glad I ran across the other thread with the same exact problem. So my initial diagnosis of a perfectly good hydraulic line was wrong. Hard to diagnosis if the initial info is wrong... Thanks everyone for the help.