B2400 HST Charge Relief

[BradB]

Hi, my B2400 has a noise when moving F or R, it's a kind of a chatter, and worse in high, but seems to be more hydraulic based than mechanical type of chatter. It moves and actually operates okay other than that. I had it to the local Kubota dealer and after a clutch and $1600 later it still does the same thing. They were going to replace the main hydro pump, but I lost any confidence in them, because the loader and attachments work fine. After researching the repair manual I am somewhat confident that it is the charge relief valve or at worst the charge pump, because, it states the charge pump is there for the smooth operation of the piston pump and piston motor, the flow chart also states to replace charge relief valve if pressure is too high. No, have no way of checking pressure at this time. Any ideas or experience on this?

 

[dfkrug]

You are right not to change the implement pump....it has nothing to
do with the HST at all. The dealer may have properly expected that
you could have a contaminated dry clutch, which could be blamed for
the chattering. Dissassembly of the clutch would have shown if
it was oil fouled or not. If dry, it was not the problem and should not
have been replaced.

As for your HST, the charge pump operates under fairly low pressure
and you need your service manual to locate the pressure test port. The
HST itself has 2 test ports...one for forward, one for reverse, and they prob
run at 4500-5000 psi.

 

[BradB]

Thanks dfkrug. The clutch they removed looks fine with no oil. Guess I will do some more investigating and check the pressures somehow. I still don't understand why the dealer didn't check the pressures, in hind sight I realized a lot of red flags went up but I ignored them. I will figure this one out and repair it myself from now on.