4035 HST hydraulic problem

[IronHorsePilot]

I have a 4035 HST that started having weak hydraulic issues. I was unloading some landscaping blocks with my qd pallet forks and the FEL would barely pick up the pallet of blocks. I quickly did some math and the FEL should have easily lifted the load. Once those were unloaded I was grading my gravel drive and I noticed as the box blade got full the tractor would bog down. I had to feather the heck out of the pedal to finish the drive. Parked the tractor and finished some other projects. Went to use the tractor a few days later and the FEL will raise but is very slow. Same with 3 point. Hooked brush hog up and it will not lift the cutter off the ground. I was close to a service so I went ahead and changed both hydraulic filters and refilled the tractor with new fluid. I also pulled the hydraulic / transmission strainer. I noticed there were some pretty big pieces of metal in the strainer. Still same problem, very weak hydraulics. Im at the conclusion that I have a trashed hydraulic pump. The question is which one? Part 15 or 29? 15 is labeled as PUMP Gear 8cc / Rev. and is $193.90 through my dealer. 29 is labeled as TANDEM Pump - Hyd and is $327.80. Hate to buy the wrong one and end up having to buy the other.

Anyone know which pump is which? My local dealer is not very helpful and the dealer I bought the tractor from no longer sells mahindra.

 

[mikeman1]

i accidentally hit my hydraulic lever that controls the rear ports and it robbed alot of power from the hydraulics. make sure your lever is in neutral. i noticed my hydraulics were really weak right off the bat and checked the lever and sure enough thats what it was. once the lever was back in neutral the loader worked fine.

 

[IronHorsePilot]

That was the first thing I checked. The arm is in the middle and if I do move it, the problem is even worse.

i accidentally hit my hydraulic lever that controls the rear ports and it robbed alot of power from the hydraulics. make sure your lever is in neutral. i noticed my hydraulics were really weak right off the bat and checked the lever and sure enough thats what it was. once the lever was back in neutral the loader worked fine.

 

[CincyFlyer]

First spend twenty bucks for a pressure gauge and whatever quick release fitting you have, and start measuring. Low pressure can be a trashed pump, or a clogged inlet filter, or a stuck relief valve. In any case, you'll want to adjust the pressure with the new pump! My 2540 was set about 15% lower than spec, so I adjusted it to the spec and gained missing lift capacity.

 

[dfkrug]

Interesting way Mahindra designed your hydraulic system, with 2 pumps end-to-end. One will be for implements, and the other for PS and usually the charge for the HST. Other tractors make that one pump with 2 gear chambers.

Regardless, before you rush off and buy a pump, check one more thing: is the inlet to the pump compromised in any way? It may be rubber or steel. If you are sucking in air, that could cause your problems. You have already checked the inlet screen, oil level, and relief, so that is good. Is your HST driving OK?

 

[IronHorsePilot]

Well, before I saw the last 2 posts I had already taken the hydraulic pumps off. I have to give it to Mahindra here. I had them off in less than 20 min. 4 bolts to hold the inlet lines on and 2 banjo bolts for the supply lines. Then 2 long bolts that sandwich the 2 pumps together on the spline drive assembly. As I guessed, the high volume pump has a trashed bearing. The stupid thing is they are aluminum. It will only get picked up by a filter, not a magnetic plug. I guess now I know where all the metal shavings came from in the strainer.

I found a used pump for about 50% off a new one. Problem is I also need all the gaskets and O-rings. Would like it back together sooner than later so I can have my garage back. Oh well, off to the parts store.