running skid loader with damaged pump?

[kidstrustfund]

I have a 71 IH skid loader. I repaired a line and did not manually fill the drive pump with fluid. That was not one of my brighter moments. Now I believe I have a damaged drive pump or motor. I will buy a pressure gage tomorrow and check the pressure next week. The loader still operates. But the left drive wheels are operating at a reduced rate. Also when I move my drive lever to full, the vibration coming from that motor is strong enough to move the throttle lever. My questions are. Will I damage the pump or motor if I continue to operate the machine until the end of my job? ( 2 weeks). The pump/ motor are 40 years old and replacement with the original pump or motor will probably not be an option. Can a pump or motor that has run dry be repaired? If not can the pump or motor be replaced with an after market pump? Thanks Tom

 

[wdchyd]

The damage from not filling the case on a hydrostatic pump is not going to cure itself or stay the same......

This pump should immediately be taken out, stripped down and check out the rotating groups especially the, pump section involved......the more you run it, the more you risk completely junking the pump......also the corresponding hyd drive motor that's hooked up to the problem pump should also be stripped, cleaned, inspected and resealed at the very minimum to pull out contaminates from the closed circuit.......

If not versed in hydrostats, best to find a trained eye to check out internals.....not everyone that works on hydraulics knows what to look for....and these units are precision lapped and cleaned before assembly.....

Best of luck, cuz you have a lot of work ahead.....

 

[wdchyd]

Hopefully Tom it won't cost you the "kidstrustfund" to fix it......

 

[wdchyd]

Also when I move my drive lever to full, the vibration coming from that motor is strong enough to move the throttle lever.

The pistons/shoes in the rotating group have already come apart inside the case........:thumbdown:

 

[kidstrustfund]

I quess that is not good. Will running that in that condition cause additional damage to the loop/ motor. Can that distroy the motor? The Kids are on their own. Tom

 

[wdchyd]

Yes......

 

[kidstrustfund]

I ran it 4 hrs already in that condition. It did not deteriorate while I ran it. Their couldn't be something stupid like air in that loop. Or is that wishful thinking? Is their sources for pumps and motors that would fit my application. Or should I look for a rebuilder? I know this all speculation until I put a pressure gage on the loop. Thanks for your help. Tom

 

[wdchyd]

Air would have worked it's way out very early on.....

Where are you located......

 

[kidstrustfund]

south new jersey

 

[wdchyd]

checking pressures in these is not as easy as a pump on a tractor....

It requires test port identification and test procedures from service manual

 

[wdchyd]

Dependable Hydraulic and Hydrostatic in Amityville, NY | 18 Ranick Dr W, Amityville, NY

Equipment Service Association

Baltimore Hydraulics - hydraulic service and repairs



Look for hydrostatic repair service when looking for repair centers.......I'm sure the more you investigate you'll find someone close as you are lucky to be nearer to the bigger cities.....

Once you get the unit out, you can ID this with the model code and some places offer Reman/exchange.......best to remove it then make decisions....

Pics would be nice also......

 

[kidstrustfund]

I do have the repair manual. It would have been nice if I checked the manual before I changed the hose. I have changed plenty of hoses in the past with no problem. I quess I got lucky. Their are test ports located on both lines going from the pump to the motor. I should be able to handle the test after reading the manual. Both forward and reverse on that loop are effected. I am thinking pump. The manual says to service the pump and motor as 1 unit. What happens? I am thinking the pump fails then contaminates the loop which effects the motor. Tom

 

[wdchyd]

Yes, your thinking is right.......when one component fails, it's important to rinse/inspect internals of the mating unit.......they share the same oil when operating......

 

[kidstrustfund]

I went out and messed around with the skid steer today. I added some hydraulic fluid to the reservoir . The fluid was a little low, not bad though. Then I took the fill plug off the pump and topped it off. The fluid was about 1 inch below the top. After filling the pump I noticed the fluid level receding a bit. I put the plug back on and fired her up. Most of the power to the set of wheels were the problem was returned. The noise subsided. The linkage does vibrate a bit more than it use to when under heavy load. but it was no ware near as bad as it was. I ran her 1 hr in the morning and 3 hrs tonight and she has the power back. I think By opening the plug on the pump I purged the residual air in the closed loop that got trapped. I might of been granted a stroke of luck. Thanks for your advice. By conversing with you and talking with a few local mechanics. I was able to get through this . Tom

 

[wdchyd]

A great way to purge after a rebuild or dilema is to raise the drive wheels off the ground before start-up......at idle engage levers in for/rev directions to visually confirm everything's good.......then let it run with all wheels spinning for 15 mins or so in both directions......this will purge air without straining components......:thumbsup:

 

[J_J]

wdchyd,

Would that work with a closed loop hydro system? On our PT, we have a bleed port on the VSP, and we motor the engine over for short periods. We do this when changing out filters and hyd wheel motors.

 

[wdchyd]

JJ,

My experience with doing this would be only if purging after a component rebuild/replacement on a closed loop system.......it doesn't put strain on the hyd system during start-up and prevents the "Oh-$#it" senario......

Also if something wasn't plumbed corrrectly (wheel motor going backwards), then you'd see it rather than have drive motors fighting each other destroying themselves........

Not necessary for regular maintenance work (oil & filters)