hydraulic drive issue...help

martinrdcustomz · Jan 1, 2012

hey guys..i posted on here last week about an issue i had with my earthforce ef1 D that i just purchased. it was "kicking" in and out of gear. so anyway my neighbor and i troubleshooted for awhile and figured it the be worn out hydraulic motor. so i took it to local shop to confirm my findings i and i was correct the motor was pushing oil past rollors. so during our troubloshooting of the hydro motor we turned in a pressure adjustment on top of pump..when putting the motor back in and test driving it jerked and barked like it never did before! so we adjusted the pressure screw all the way out and it runs smoothe as can be! no jerking at all...just great, but one problem...it has no "spin the back tires loose" power at all....and it will slow way down climbing a small grade and after it get warm it wont climb the grade at all. does anyone have any idea what could be happening? we put a pressure gauge on the pump and was getting good pressure but not sure if we are gettin the flow...maybe somehow gettin pressure from other side and not lettin it get up and go. any info would be appreicated. thanks guys

oldnslo · Jan 1, 2012

martinrdcustomz said:
hey guys..i posted on here last week about an issue i had with my earthforce ef1 D that i just purchased. it was "kicking" in and out of gear. so anyway my neighbor and i troubleshooted for awhile and figured it the be worn out hydraulic motor. so i took it to local shop to confirm my findings i and i was correct the motor was pushing oil past rollors. so during our troubloshooting of the hydro motor we turned in a pressure adjustment on top of pump..when putting the motor back in and test driving it jerked and barked like it never did before! so we adjusted the pressure screw all the way out and it runs smoothe as can be! no jerking at all...just great, but one problem...it has no "spin the back tires loose" power at all....and it will slow way down climbing a small grade and after it get warm it wont climb the grade at all. does anyone have any idea what could be happening? we put a pressure gauge on the pump and was getting good pressure but not sure if we are gettin the flow...maybe somehow gettin pressure from other side and not lettin it get up and go. any info would be appreicated. thanks guys

What pressure are seeing? Do you know what the system pressure should be? Pressure provides the torque while flow provides speed.

Roy

martinrdcustomz · Jan 1, 2012

well...a guy from bobcat dealership told me that it aint the "right" way to do it but u could plug the one hose comin off the pump and see if it stalls the motor out..then u know it isnt the pump...we did that and it barley bogged the motor...i mean just a little bit. put pressure gauge on it and a lil about idle had 500. then a lil more throttle gave me 1500..then maybe half throttle gave me 2000. i have no idea what the pressure should be...dont know anything about these machines and frankly i cant find anything out about them on the internet. guy from bobcat said he has to hook it up to flow meter to see how many gpm im getting. so i guess tuesday thats what im doing. just was hoping someone had a solution or some insight into what i might be getting into. as it gets hotter it gets worse but even cold at wide open throttle it wont spin the tires..so something isnt right. other than that it is a nice little machine.

Ford tractor · Jan 2, 2012

martinrdcustomz said:
well...a guy from bobcat dealership told me that it aint the "right" way to do it but u could plug the one hose comin off the pump and see if it stalls the motor out..then u know it isnt the pump...we did that and it barley bogged the motor...i mean just a little bit. put pressure gauge on it and a lil about idle had 500. then a lil more throttle gave me 1500..then maybe half throttle gave me 2000. i have no idea what the pressure should be...dont know anything about these machines and frankly i cant find anything out about them on the internet. guy from bobcat said he has to hook it up to flow meter to see how many gpm im getting. so i guess tuesday thats what im doing. just was hoping someone had a solution or some insight into what i might be getting into. as it gets hotter it gets worse but even cold at wide open throttle it wont spin the tires..so something isnt right. other than that it is a nice little machine.

....
Shudder....

It takes about 1/100th of a second for a dead headed hydraulic system to cause permanent damage to the pump. If you dead headed a line before the relief valve, then it's probably time to buy a new pump. Could be wrong, but...

SSdoxie · Jan 2, 2012

There are 3 pressure adjustments on that pump system that need to be checked and adjusted. There are also internal non-adjustable high pressure reliefs, these reliefs seldom if ever open if the other pressures are correct.
Pressure checks MUST be done in specific order.
1st is charge pressure - this is the adjustment screw on top of the pump you have been turning. High charge pressure can cause jerkiness, and force pump to work to hard & loading the engine.
2nd is Flushing valve adjustment - this dumps some of the charge pressure oil off the low side in hydro pump to motor circuit for oil cooling and helps give pump a smooth transition from neutral to travel when pedal is stroked. Flushing valve should drop charge pressure 30 pis when pedal stroked and return charge pressure to 320 psi going back to neutral. Adjustment screw is on right side of pump and faces forward.
3rd is torque limiter - this balances the combined load of the hydrostatic pump and the loader gear pump to prevent severe engine load when pushing hard into a pile and loading/lifting bucket at same time. If adjustement is too tight will cause end lug or die under load, if to light it will let drive system slip with no load on engine. This adjustment screw is underneath the pump.

These adjsutments can get a little complicated because as each is adjusted or changed you must go back and reset the prior settings. I recommend you let the dealer go through this. If all adjustments check out and still can't get drive power the pump has suffered same type of damage as the drive motor.

martinrdcustomz · Jan 4, 2012

thank you for the very informative reply! yes i know the 3 adjustments u are talking about and it makes sense...i took the dealer yesterday to have them check flow on pump...they said they had to adapt there flow meter to the goofy overseas fittings so they didnt test it yet however said they thought it might not be pump it just may need adjusted...i guess they were trying to find certain specs or what not...we just adjusted the top one out the get the pump to stop chattering and jerking...we adjusted the other 2 out all the way also but i can see how u need to have them all fine tuned together in order to work properly...hopefully thats what it is and the dealer gets it set right. thanks again for your helpful info and i will keep posted on results.

SSdoxie · Jan 5, 2012

Just an FYI here the fittings in the pump are BSP (British Standard Pipe), so to test with our common US connections they need to adapt to form BSP to 37 degree flare. I also noticed in research the Earthforce manual was very limited in information of setting this pump, but Bobcat did a good job of explaining this in their version after the purchase of the company and rewriting the manuals. Use pump setting for the B100.
Who is the dealer you are working with? Maybe I can give then a call and help out if need be.

martinrdcustomz · Jan 7, 2012

the dealer i was working with is called bobcat of johnstown...they informed me that they didnt have the fittings ur talking about to adapt over to hook gauges up...said it would be $75 for the fittings and i would have to pay...however the they give me 3 pages of how to set it up and adjust the pump..so in the mean time i found a earthforce service manual on ebay and bought it. and i also ordered the fittings i need on my own...so as soon as they come in i will attempt to set the pump according to the instructions. it said the charge pressure should be 320 at 1000 rpms and then the flush valve should drop that pressure by 30 pnds. but it doesnt give me what the max pressure should be on the torque adjustment. just says to turn screw in 3 turns. then max throttle and record pressure. then it says to back it off 100 pnds. then at the bottom it basically tells you if u want more power to wheels turn it in or if u want more power to front end loader turn it out...it acts as id the torque adjustment is turned all the way out....loader and how work great just doesnt have and torque. also i think im gonna change the hydraulic fluid too bc i have no idea it whats in it is even the right stuff. i appreciate you help sir. i will keep u posted on my results...hoping fittings are here this week.