Go Bottom1991 B7100 HST
 | dannycora
Join Date: Jun 2005 Posts: 6 San Diego 
|
2005-10-13 117826
I have a 1991 B7100 HST with 800 hours. When going in reverse, it is slow and sometimes I have to increase rpm for it to creep along slowly. It does better on high than in Lo speed. I check the fluid and it is slightly overfill. It also has a growling/vibration in reverse. About a year ago, I had water contamination in the transmission but I changed and flushed with new filters and fluid. Any advice is greatly appreciated. Dan
Reply to |
Quote Reply |
Add Photo1991 B7100 HST
 | Chief
Join Date: Jul 2003 Posts: 4297 Southwest MiddleTennessee 
 Pics
|
2005-10-13 117828
Water contaminatin is VERY difficult to completely flush out. It has been my experience that it may take more than a single drain and flush. The water combines with other contaminants and can cause a build up of "crud" which can not only readily clog up or restrict the filters but the pickup screen as well. Have you tried to drain a quart to half gallon of fluid into a clear container to observe what the color and condition of the oil looks like? ....
Reply to |
Quote Reply |
Add Photo1991 B7100 HST
| dannycora
Join Date: Jun 2005 Posts: 6 San Diego
|
2005-10-13 117834
No, I have not drain and check the color of the fluid but the dipstick shows clean fluid. I am thinking about taking it to the dealer but I thought I would try and fix it myself if I can. Is there a way to power flush ? I will try and repeat the fluid change and new filters again. What's with the growling/vibration ? Do you think the check valves or orifices in the transmission is clogged ? Thanks in advance for any advice. Dan ....
Reply to |
Quote Reply |
Add Photo1991 B7100 HST
| Chief
Join Date: Jul 2003 Posts: 4297 Southwest MiddleTennessee
Pics
|
2005-10-13 117839
Please excuse the lengthy reply but I figure a basic troubleshooting list would be of more help to you than my trying to type it all out. Hopefully is should give you a few ideas as to what to look at. Most hydrostatic drives are similar and fairly basic systems with the exception of the electronics of the Deere 4000 Ten series and up which is where this trouble shooting list came from. Disregard the parts about the pedal potentiometers and related electronics. I agree that the growling noise is typically caused by air that needs to be purged fromt the system.
Symptom: Machine Movement Problem
(1) Wheels On Machine Will Not Rotate?
Yes - Check torsional damper between engine and
pump
Yes - Hydraulic oil level low in transaxle
Yes - Low charge pressure. See Tests and
Adjustments section.
Yes - Internal pump or motor damage or excessive
wear
Yes - Parking brake engaged or malfunctioning
Yes - Transaxle malfunction. See Final Drive Power
Train section.
Yes - Forward/Reverse proportional valve
malfunction
Yes - Pedal potentiometers neutral position not
properly adjusted, Debris under pedal(s) or pedal
return spring problem
Yes - Seat switch malfunction
(2) Noisy Pump or Motor?
Yes - Hydraulic oil level low in transaxle
Yes - Main drive pressure relief valve stuck open.
See Tests and Adjustments section.
Yes - Air in system. See Hydraulic System Bleed
Procedure.
Yes - Internal pump or motor damage or excessive
wear
Yes - Parking brake engaged or malfunctioning
(3) Sluggish Response To Changes In Speed?
Yes - Hydraulic oil level low in transaxle
Yes - Low charge pressure. See Tests and
Adjustments section.
Yes - Main drive pressure relief valve stuck open.
See Tests and Adjustments section.
Yes - Air in system. See Hydraulic System Bleed
Procedure.
Yes - Hydrostatic pump output pressure too low.
See Tests and Adjustments section.
Yes - Internal pump or motor damage or excessive
wear
Yes - Forward/Reverse proportional valve
malfunction
(4) Low Power?
Yes - Hydraulic oil level low in transaxle
Yes - Low charge pressure. See Tests and
Adjustments section.
Yes - Main drive pressure relief valve stuck open.
See Tests and Adjustments section.
Yes - Air in system. See Hydraulic System Bleed
Procedure.
Yes - Hydrostatic pump output pressure too low.
See Tests and Adjustments section.
Yes - Internal pump or motor damage or excessive
wear
(5) Wheels Rotate In One Direction Only?
Yes - Main drive pressure relief valve stuck open.
See Tests and Adjustments section.
Yes - Forward/Reverse proportional valve
malfunction
Yes - Pedal potentiometers neutral position not
properly adjusted, Debris under pedal(s) or pedal
return spring problem
(6) Machine Does Not Move When Forward or
Reverse Pedals Are Pressed?
Yes - Hydraulic oil level low in transaxle
Yes - Low charge pressure. See Tests and
Adjustments section.
Yes - Internal pump or motor damage or excessive
wear
Yes - Parking brake engaged or malfunctioning
Yes - Transaxle malfunction. See Final Drive Power
Train section.
Yes - Forward/Reverse proportional valve
malfunction
Yes - Pedal potentiometers neutral position not
properly adjusted, Debris under pedal(s) or pedal
return spring problem
Yes - Seat switch malfunction
....
Reply to |
Quote Reply |
Add Photo1991 B7100 HST
| dannycora
Join Date: Jun 2005 Posts: 6 San Diego
|
2005-10-13 117844
Thanks for the list. I will check it out as much as I can and if I cannot fix it, I will probably go to Kubota. Thanks again and you have a good day. Dan ....
Reply to |
Quote Reply |
Add Photo
Go Top
Share This