Scag Hydraulic problem-help please

[GSmith4965]

I just recently purchased a 2007 scag tiger cub with a blown engine. The tractor has 1100 hours on it I bought the machine for home use from a private owner who used the machine commercially. After installing the new engine, I found out that the left wheel operates fine but no movement on the right wheel at all

I have made sure the brake band was not stuck
There are no hydraulic leaks anywhere on the machine and prior to starting the new motor I changed the hydraulic oil and filter as per the manual.

When jacked up and the motor off, the right wheel moves freely by hand as does the left
When the motor is running the right wheel is locked from moving in either direction
Attempts to move the steering arm forward or backward when the motor is running do not allow the right wheel to move at all

Both pump dump valves are securely shut
When running, the left steering handle is nice and smooth
Small movements of the left steering arm produce changes in direction of the left wheel as it should
The right steering handle is much more stiff/sluggish and harder to move but not extremely

Questions
How do I know if I have a bad hydraulic pump or bad motor???? Is there a procedure to diagnose one or the other?
Are these rebuildable???
Could it be a more simple fix?? Perhaps a relieve valve sticking??

I am new to zero turns and would greatly appreciate some help from the experts

Thank you

 

[Carl_NH]

Could be several things and I am not an expert..BTW..

Air in the system on the right side? you might try opening/closing the dump valve on the right side pump which would bypass all the oil and may remove air. It sort of sounds like a valve or deadheading on the right wheel motor.

Second, do you have enough length of hose to swap pump lines left to right? Worst case would be swap motor side to side.

Are these parker or hydrogear pumps/motors? Replacement sets are about $800 pump and wheel motor.. so not a cheap fix so you probably want to narrow this down.

 

[Tough Luck]

Try Carl's recommendations, if that doesn't work, call your local Scag dealer and see if they can perform a flow test.

I have a '07 Scag Wildcat with almost 1100 hrs and have encountered issues with the left side drive. I tried to bleed the system and finally took it to the dealer for a flow test. After $50 flow test, they determined it was the motor with replacement cost of $580! Mine has hydrogear system. I figured it was worth a try to fix it, so I tore the motor apart and it looked good to me, but I'm definitely not a mechanic. I decided to try a seal kit with the thought it may be sucking in air although there were not noticeable oil leaks. The seal kit was $80! These are really expensive units. I'm trying to figure out how to pull the needle bearing race so I can get the seal out.

Sorry for such a long post, hope this helps.

If anyone has ideas on pulling a 42mm needle race w/o destroying it, let me know. I can't find a blind bearing puller that large.