I'm new to this page but have been reading any post relatable to try and fix my issue and after a couple months of trying and no luck I figured I'll make one myself. Started about a couple months ago. Was using grapple bucket on skid loader was working fine. Next day a contractor went to switch buckets and he couldn't lift up the bucket. Brought the machine to the shop and saw one of the plates on the bottom of the tandem pump have came loose and some of bolts were loose. Took the pump out inspected the flywheel it has the update spline coupler. Re seated the plate and bolted everything down and installed. Still wont lift a load. Next step took gear pump off saw some scoring on the inside. Decide to replace it with a new one. Once installed it did improve things but not much. Was able to lift a load a little bit more. PSI reading off the aux hold is around 2000-2300 PSI seems to want to creep down as I hold down on the control. Next replaced boom relief valve and system relief valves. Tried adjust the valves both ways didn't change anything. So the skid loader itself drives great. Seems to have normal speed boom up and tilt up but under a load it just wont do anything. When trying to do 3 functions at a time the 3rd one say boom up, tilt up and then try to turn left or right, it wont move left or right it just makes a grinding noise. Or say driving straight, tilt up and boom up. Boom up didn't do anything. So the third operation seems to never want to do anything. There are no air bubbles in the hydraulic system and is at the correct level. Last thing I tried was detaching the lift cylinders to see if they were deadheading but they both move in sync and have great force in both directions. I'd appreciate any suggestions i'd like to get this machine back to work. Thanks,
Make sure your auxiliary hydraulics are off. It sounds like they are engaged and loading your pump over relief
Thanks for the quick response, I have also thought this could be an issue. Other than hearing the engine/pump bog down when I cycle the lever back and forth it seems like its off? I can also visually see the cable move in and out beneath at the valve body. Maybe its not fully disengaging?
Welcome to HEF gwizz15 ! Can you post pictures of the old pump and the wear? Also was the splined pump coupler between the hydraulic gear pump and the hydrostats in good shape? How about the bushings in the hydrostatic pump where the hydraulic pump bolted on?
Hi mg2361, Thanks for responding, good thing I have a couple pictures prior to installing the new pump. The bushings still felt tight.The old splines were in perfect shape with no play in the spline engagement. Now that you mention that plug.. Is that the blue plastic cap? That looks all chewed up on mine? On the old pump it was mainly scoring on the sidewalls. Enough to catch a fingernail on a couple. Other then that the cap with the silicone seal (#7) that covers the splines was also very sloppy. I can post more pictures later if interested?
Yep. It looks damaged and that would allow Hydraulic oil pressure to leak into the case drain of the hydrostatic pump.
So your saying a 10 dollar plug could potentially be causing of the issue? I mean I saw how beat up it was but didn't think a plastic little plug would do much and figured it must have been like that for a while. Like someone installed it stupid. So I'm going to go off a hunch that some crap got through at the quick discount coupler went straight to the gear pump did some damage and those parts bounced around in the little crevice and did that to the plug? I'll order a plug... I'll let you know if it changes anything. Thank you for your help.
Installed that plug the other day. After a little warm up was able to raise the boom on low idle like nothing. Machine now reads 3000 PSI. Feels better then it ever did before. Worked the machine for 20 minutes or so and had to tighten a fitting. Ran for another hour and now to find another leak. But a leak is nothing a this point thats just a matter of find it. I just hope its not those bottom covers on the tandem pump those sucked to put on! The real issue has been fixed. Thank you for you help its very much appreciated.