help deere 250 hydro issues.

[brapp]

Given you know some debris was introduced to the system reservoir I would be looking at the low pressure fluid feed to the problem pump. Commonly called the charge line. Blockage could be in a T fitting that sends fluid to both pumps. An IR point and shoot thermometer would tell you if you have a blockage due to heat change at the blockage. I worked on a brand new unit with no drive to one side it was set up to feed both pumps from the filter housing that was cast aluminum. The feed to one pump was completely blocked with casting slag. Needless to say that housing was overnighted to the manufacturer and we sent the entire unit back. Tazza is right about the paper all the manufacturers specify a lint free enviroment. If you had no fluid in the problem pump due to a blockage at initial startup you may have scored the mating surfaces badly enough to ruin the pump. At some point the blockage may have passed but the damage was done. If you can verify the problem pump has charge fluid I would suspect it is bad; but I would check the motor lines with a guage to verify.

what i do not know and cant comprehend is how does the fluid get from the charge pump to the problem pump?? is it internal ports or is it a external line that i am overlooking. i have literaly spent hours apon hours reading up on the hydrolic system on this machine. and i do have flow out the manifold for the drive motor just not enough to turn it( possibly just charge pressure) i have even went to the extent and printed out all 400 some paged of the manual and been takign it with me so when i have a few mins and a free mind i can look at it to see if there is somethign i am not comprehending or overlooking

 

[Tazza]

what i do not know and cant comprehend is how does the fluid get from the charge pump to the problem pump?? is it internal ports or is it a external line that i am overlooking. i have literaly spent hours apon hours reading up on the hydrolic system on this machine. and i do have flow out the manifold for the drive motor just not enough to turn it( possibly just charge pressure) i have even went to the extent and printed out all 400 some paged of the manual and been takign it with me so when i have a few mins and a free mind i can look at it to see if there is somethign i am not comprehending or overlooking

Are the pumps all inline? or seperate?
I only know how bobcat have their pumps setup, they are all inline, the charge pressure is generated by the fluid returning to the tank and maintained by a relief valve, this oil goes into the case of the hydrostatic pumps, this is a common housing for both pumps. With this setup, no one pump can lose charge pressure as there is a hole about 3/4" linking both pumps.
Can you move the drive motor from the working side to the non working side? Its a good test to see where the issue lies....

 

[frogfarmer]

Are the pumps all inline? or seperate?
I only know how bobcat have their pumps setup, they are all inline, the charge pressure is generated by the fluid returning to the tank and maintained by a relief valve, this oil goes into the case of the hydrostatic pumps, this is a common housing for both pumps. With this setup, no one pump can lose charge pressure as there is a hole about 3/4" linking both pumps.
Can you move the drive motor from the working side to the non working side? Its a good test to see where the issue lies....

Your tandem pump does have the charge pump internal but there are ports externally if the plugs will come out to check the pumps individually. The hydros are unitized but there is a pump for each side inside the tandem pump case.

 

[brapp]

Your tandem pump does have the charge pump internal but there are ports externally if the plugs will come out to check the pumps individually. The hydros are unitized but there is a pump for each side inside the tandem pump case.

i will check for plugs and i will see what i can do here this afternoon, i am workign in the home office today so i will have a hr or 2 to look it over with a clear mind . if i decide to just have the pumps rebuilt and start over with a clean fresh slate possibly rebuild other drive motor and start over fresh and flush allthe lines out and start over with a empty system

 

[frogfarmer]

i will check for plugs and i will see what i can do here this afternoon, i am workign in the home office today so i will have a hr or 2 to look it over with a clear mind . if i decide to just have the pumps rebuilt and start over with a clean fresh slate possibly rebuild other drive motor and start over fresh and flush allthe lines out and start over with a empty system

As bad as that sounds initially I have done it more times than I can count due to a failed component contaminating the entire system. When the pump assm costs 5k you cant take a chance on whether it will be OK or not. Hope all turns out well.

 

[brapp]

As bad as that sounds initially I have done it more times than I can count due to a failed component contaminating the entire system. When the pump assm costs 5k you cant take a chance on whether it will be OK or not. Hope all turns out well.

well if thats the case and it cost me 5 k to get the pump figured out i will part it out before then. that 2.9 turbo diesel would make a heck of a wood splitter lol but i will try and see what i can do to rebuild it .

 

[Tazza]

well if thats the case and it cost me 5 k to get the pump figured out i will part it out before then. that 2.9 turbo diesel would make a heck of a wood splitter lol but i will try and see what i can do to rebuild it .

Hopefully its something simple.
Its just odd that you have a total loss on one side only.
You said you got new bearings and seals, just what was gone in this motor?

 

[brapp]

Hopefully its something simple.
Its just odd that you have a total loss on one side only.
You said you got new bearings and seals, just what was gone in this motor?

the brake seal on the putside went bad and dumped hydro oil into the chaincase. so i pulled the entire assembely and took it to a retired heavy equipment mechanic i know and now dont have anything from the pump once re installed.

 

[Tazza]

the brake seal on the putside went bad and dumped hydro oil into the chaincase. so i pulled the entire assembely and took it to a retired heavy equipment mechanic i know and now dont have anything from the pump once re installed.

Just a seal should not have put anything into the system. If it was a bearing then yes, it could have taken the pump out with it too.....
What did your mechanic mate say? does he have any ideas?

 

[frogfarmer]

well if thats the case and it cost me 5 k to get the pump figured out i will part it out before then. that 2.9 turbo diesel would make a heck of a wood splitter lol but i will try and see what i can do to rebuild it .

I didnt mean to imply it would cost 5k to fix your pump I was refering to the cost of a pump assm when you replace the entire unit. In a commercial shop it isnt always feasible for us to repair a pump assm. For the same reasons we dont rebuild engines we install remanufactured engines with waranties. If your pump actually has a problem I would bet you can fix it for a thousand dollars or less. Most likely you will have some scoring or sealing surfaces that needs to be cleaned up.

 

[brapp]

I didnt mean to imply it would cost 5k to fix your pump I was refering to the cost of a pump assm when you replace the entire unit. In a commercial shop it isnt always feasible for us to repair a pump assm. For the same reasons we dont rebuild engines we install remanufactured engines with waranties. If your pump actually has a problem I would bet you can fix it for a thousand dollars or less. Most likely you will have some scoring or sealing surfaces that needs to be cleaned up.

well i have a pair of s185's and a deere332 rented this week and have all 3 of my employees runnign them and once i get everythign cought back up i plan on pulling the deere250 into the basement of the house and havign a clead dust and dirt free enviroment to tear it apart and do it right. i will go back trough the drive motor i had apart and pullthe pump that is not workign corectly and try and diagnose it .

 

[frogfarmer]

well i have a pair of s185's and a deere332 rented this week and have all 3 of my employees runnign them and once i get everythign cought back up i plan on pulling the deere250 into the basement of the house and havign a clead dust and dirt free enviroment to tear it apart and do it right. i will go back trough the drive motor i had apart and pullthe pump that is not workign corectly and try and diagnose it .

I would look very closely at the drive motor since that is the one component you had serviced. The entire problem could be there. Let us know what you find.

 

[brapp]

I would look very closely at the drive motor since that is the one component you had serviced. The entire problem could be there. Let us know what you find.

once i get it back inside i am goign to buy guages and fittings and run pressure test on it and see if ther eis anything that is restricting it or if there is debris blockign flow to that pump. i could really use a diagram of the pump itself and how the hydro fluid flows trough them so i can understand and grasp the concept of it also. ther eis a also a good chance dirt or somethign could have gottien into the system for it beign open for so long .