[AT] OT(?) Cub Cadet 1812 Hydro question

[DBigdog]

Steve,
    Paul Bell is quite knowledgible on cub cadets so I forwarded your 
question to him.  His response is:

It's time to replace the valves. Actually, they are pressure relief valves, 
and are an "automatic" valve in that they automatically dump the pressure 
when the tractor is shut down, and it will then allow you to move or push 
the tractor. The earlier versions had a button in the center where his has a 
vent, and there was a lever to move that pushed the buttons down to dump the 
pressure. When they start leaking it time for a replacement. The "O" rings 
are on the outside of the valve body and are to seal around it when it is 
installed. Someone did post a so call fix or repair at one time, but it 
involved using a lathe to open up the valve and the remove the plunger for 
cleaning and repair, and then welding everything back up. It's better to 
replace them, although new ones are pricey, but most people just look for 
good used replacements. A new one is over $100, used ones are about $40-$50 
a pair.

BD

----- Original Message ----- 
From: Stephen Offiler
To: Antique tractor email discussion group
Sent: Sunday, May 31, 2009 8:16 PM
Subject: [AT] OT(?) Cub Cadet 1812 Hydro question


OK, it's not an antique farm tractor, guilty as charged.  It is a 1988
Cub Cadet (MTD built, a.k.a. "Cub Cadet Corp.") and it is a Model
1812, which is built off the same tooling as a real IH Cub Cadet Model
782 or so I am told.  I know all about the "IHCubCadet" online forum,
but nonetheless figured I'd start here on ATIS.  My goal is simply to
repair this machine so I can make the call whether I want to keep it
and mow with it, or sell it and buy a modern Zero-Turn-Radius mower.

The basic problem is a leak from the hydraulic system.  It was serious
enough (say a quart every 15-30 minutes into the cake pan that I was
forced to rig underneath the machine) that I parked it a couple years
ago, and here I am today, living proof that occasionally you DO get
that Round Tuit.

I've got the factory service manual, and it tells me I've got the
Sundstrand hydrostatic transmission.  With the sheetmetal stripped
from the steering wheel back, a good power-washing and running off a
remote battery connected with jumper cables, I found the source of the
leak, and mercifully it looks like something REALLY simple.  The pump
has two check valves threaded right into the top, very easy to access
with no further disassembly.  They are identical, and they each have a
tiny vent hole centered in the top.  The leak comes from this vent
hole.  The book says these valves cannot be serviced beyond
replacement of the o-rings, and removal and inspection of the faulty
valve shows that it is crimped together and cannot come apart, so I
agree with the book.

My specific question is this:  if the check valve is leaking out the
tiny vent-hole in the top, does that mean O-ring replacement, or do I
need to chase down a whole new valve?


Thanks and best regards,
Steve O.
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