VXD 4200 Hydraulic pump replacement

jmcallister · Mar 6, 2019

Ventrac's service support is in school for a couple days, and I'm in a time crunch.

Had some issues with our 4200, went to change the filters and lo, there is metal contamination in the oil. Oh goody.

Pulled the top off the drive pump, and it's in pieces internally. Yay.

So, anyone with experience in replacing the closed loop system on a 4200? Is it necessary to pull the engine to replace the pump and front drive motor? Do I need to worry about damage to the open loop side of the system? Tips, tricks, suggestions and commiserations all welcome.

Thanks,
JI McAllister

MountainBuck · Mar 6, 2019

There are 4 possible engines in that model. Three made by Vanguard and one Kawasaki. Which one do you have?

Do you know what might have happened? Does it see regular service? How many hours does it have on it?

jmcallister · Mar 6, 2019

Excellent questions. It's the 950G engine by Vanguard.

The thrust plate appears to have disintegrated along with most of the swash plate. Possibly something to do with not changing the filters often enough (according to what I know now, not what the manual for the tractor said), but I'm not completely sure, unfortunately.

Best guess, the tractor has around 2500 hours, but as it was purchased used with a broken tach/hour meter, that's just an estimate.

oldnslo · Mar 6, 2019

JMcallister,
Since this is a hydrostatic drive there is a very good chance that the wheel motors are also damaged from the pump failing. Sorry to be the bearer of bad news....

johara1 · Mar 7, 2019

oldnslo said:
JMcallister,
Since this is a hydrostatic drive there is a very good chance that the wheel motors are also damaged from the pump failing. Sorry to be the bearer of bad news....

Ventrac doesn't use wheel motors.. jim

jmcallister · Mar 7, 2019

No wheel motors, they're... what would ya call it? Transaxle mounted motors? One forward, one rear.

This jives with what I suspected though, that they're likely also shot. Which doubly sucks, since I just replaced the rear one about a month ago. Anyone ever send out motors like that to be tested in a specialty shop?

johara1 · Mar 8, 2019

A powertrac uses four wheel motors, a Ventrac uses two motors one on each trans axle. I had one go on an other machine and replaced parts that couldn't be resurfaced or repaired..... but you have a lot of cleaning and flushing to do..... jim