Just tried to purge air again. Seems like it is the issue? Un screwed the tow screw completely. Then back in most of the way. Jacked it up and ran the levers back and forth with the tow screw loose and tight but still having intermittent surging. The wheel goes forward for 5-6 seconds there I hear chattering and lose power, wait and then it comes back slightly.

I do not see air bubbles in the reservoir unless I have the tow screw loosened. Even then it is barely noticeable.
.should I pull the wheel motor? It definately sounds like the noise is coming from the wheel motor

 

I received my parts to rebuild the old wheel motor and did last night. I decided to see if it was the wheel motor causing the surging and the rebuilt one does the same thing. gives forward speed for 5-6 seconds then slows down for a couple seconds and speeds up again.

I dont know how it could still have an airlock somewhere....

all the connection seem tight and there is no oil leaking. no bubbles in the reservoir.

 

Check belt?

 

A lot of times if it chatters while turning one way the belt is loose as what fireball stated. Sound like an air issue. Bleed till you think its ok then bleed it some more.

 

the belt is tight. i can replace it just in case. any suggestions on bleeding? I have bled it via normal means on what the manual says (jacking up the mower, ive ran it for 30 min or more, with the tow belt open and closed) and via loosening the top cap of the hydro pump probably 5 times at least. oil does flow out

 

You mentioned tow belt, are you opening the bypass/ tow valve? If not try what your doing mower jacked up w/ the tow valve open multiple cycles and then closed multiple cycles. If that does not clear up may be trash/ debris in the hydraulic system.

 

Sorry yes tow valve. Multiple cycles open and closed. Just did it again tonight. Still is ok 5 seconds and then not ok.

This is all on the left side. The right side has been fine the entire time

 

I think I'll just pull the pump next week and tear it down. Drain the fluid and start over

 

Good chance it has debris in hydraulic system.

 

tore the hydro pump out today. opened it up. and didn't take long. the cylinder barrel I inspected and 2 cylinders are completely stuck in the up postion. I un jammed them and tried swapping them around and the same two will stick. guessing it got hot and warped at some point.

ordered a new cylinder body and ill let you guys know if that is the fix

 

As you can see the barrels all stick but two are completely jammed.

Just figured I'd take a picture while I'm waiting on parts to rebuild it

 

Good deal looks like progress. Thanks for the picture and please let us know how it goes.

 

So i cleaned out the pump, replaced the cylinder piston and filled it with oil.
Ill tell you the air purging process described by exmark does not work. at all... as in loosening the tow screw 1.5 rotations and pressing the levers back several times. tried this for over an hour.

what did work was removing the top of the hydro pump and letting oil leak out and then using a long funnel to top it off.

problem solved

Im guessing after the seal blew out of the wheel motor the system lost too much oil and over heated the hydro pump making the cylinder piston expand.the total costs to fix the wheel motor replaced the end bushing and both bearing on the end of the shaft) and hydro pump was only around 200 bucks including the hydro oil. no metal flakes in the WM or the pump. As a side note rebuilding a hydraulic pump is easy anyone should be able to accomplish this. the wheel motor on the other hand you must be very careful with how you disassemble, one error could lead to a waste of time and money.

It is interesting to me aster searching everywhere on this forum no one else had an issue like mine so i hope this helps someone.

 

Yep it will help someone! You can never have to much info, well when it comes to repairing things that is! Hope she's ginning!

 

Good information!