Sk 120 won't track

[cooberb78]

I still can't get my machine to track properly. When I check a1 and a2 they don't have but about 200psi when travel valves are moved (cable operated). Left travel works sometimes and I get pressure increase at pump. If I hold the right pedal down after a while it will kick in at full speed and I get pressure increase at pump. Have went through book on all pressure measurements for all functions. All pressures are spot on except travel. Measured at pump,T in at top of swivel and T in at right motor no pressure

 

[mikebramel]

What kind of controls does it have, open center loadsensing

 

[cooberb78]

Sorry but i dont know what that means

 

[mikebramel]

You're measuring the outlet pressure but you need to figure out what controls the displacement of the pums?

 

[cooberb78]

The pumps are negative controlled by pilot pressure

 

[cooberb78]

If a am testing pressure at the a1 and a2 test ports at pump and get no pressure how do you know if the pump is bypassing or if the internal regulator is not advancing swash plate

 

[mikebramel]

Thats what Im saying, you need to know what the pump is "seeing"

 

[cooberb78]

Ok got ya. So I think I have four pilot signals going to pump. Should I dead head test them or T test. I would guess to do both in case problem is down stream.

 

[cooberb78]

Ok I T into my pilot negative control's at the pump. All levers in neutral at full throttle 500psi at both pumps. Left travel lever engaged I have no pressure drop I'm guessing this is causing my low power on left side. Right travel lever engaged I have pressure drop below 200psi and I can hear the pump change sounds like it is struggling but no pressure from pump to travel motor. (Brake spool and springs seem fine)