Weak travel motor 335

[neller840]

I have a 335 excavator. The left track has started getting weaker, but only going forwards. Reverse it tracks ok(equal power), but forwards the left track is weak. I've tried easy things: checked track tension, control linkage, checked travel motor case drain.
A friend thought it was the travel motor's control valve o-rings. I am no hydraulic expert, and want to diagnose this properly, before I pull a valve manifold off. Any advice as to next things to check?

I was going to buy a pressure test kit, but I can't find great troubleshooting steps. I want to get a kit that will have everything needed to test this and other circuits. I know testing flow is really important as well. Any advice on tools to add to my arsenal for troubleshooting this?

Thanks for reading and any help you might offer!

 

[neller840]

Also was reading about making my own test kit from:

MEL1355 Pressure Test Kit for Bobcat 331 Excavators

Tazza, I've been doing a lot of reading and I came across a post, long ago, where you discussed checking hydraulic pressure etc. The manual says to use a MEL1355 Pressure Test Kit....well, the sticker shock has me thinking about making my own test kit. I came across a site that listed all the...

www.skidsteerforum.com

Trying to verify the test port on a 335 is a "Dixon 1PDF2....(1/4" NPT on backside)"

I would need 1/4" npt female to female hose and that would get me started? With a 5000psi gauge?

Also was wondering if I could test pressure out of the control valve for my left track, and then at the motor. Wouldn't a discrepancy show any swivel issues?