[AJD] JD B Powertrol trouble

[Daniel W. Oehmke]

I hooked up the one-way hydraulic cylinder for a mower/conditioner to a
JD B and think I blew out the powertrol.

The conditioner had been in the travel position with the cylinder partly
extended.  The powertrol was already pretty full of oil before I hooked
it up.  Once I pushed the powertrol handle to the rear and lowered the
conditioner --- well, after that the powertrol just wouldn't lift
anymore.  

After I hooked up another tractor to the conditioner and it rose up and
down just fine --- I thought that by lowering the conditioner, it forced
too much oil into the already full powertrol on the tractor, blowing
gaskets or o-rings.  

I looked in the shop manual, but it doesn't have much help.  Can anybody
help explain what to check for?  Is it possible I may only have to
replace some o-rings in the powertrol, rather than take the rockshaft
off to check/replace the gasket the back side of the powertrol's piston
cylinder? And before removing the piston to check the leather cup on top
of it?

And what's the reference for working on the small parts within the
powertrol itself?

Thanks!

Dan Oehmke
Welch, MN