I recently replaced a bad hyd. Pump and it has worked great for a month. Today it started to lift slow and will not lift at all at idle I cked the pressure at tank and its fine 3900 psi. It acted like maybe a lift cylinder had went bad so I raised it all the way up and took the lines off one side at a time and no oil passing by the piston. It will raise from ground to full height in 10.5 seconds witch is 3 seconds to long but the tilt is 6 seconds. Any input would be great I'm thinking I need to go into the tank but don't want to till Im sure that's where I need to be. Thanks in advance first time user. George
I suspect the old pump had the cartridge side plates blown apart and or a cracked rotor. That would generate a lot of contamination that might be sticking a valve or dammaged your new pump. Check the pump pressure again while lifting and tilting at full and half throttle and come on back please. Later Bob
It has 3900 psi stalling I had the bypass valve apart and didnt have a gauge to set it back toll now so thats why its a little high in psi. Question can I get to the valves to clean them through the filter housing? I was also going to try to reverse the pilot valve hoses and see if that would tell me anything since the tilt and dump work normal? Thanks
Bruiser, I have a similar issue with my 953c. Started all of a sudden. The tilt is not as slow as the lift. The lift is very slow and only works at full throttle. Anyone got any suggestions?
LMitchel any noise from your pump? Do you have access to a 5000 psi gauge ? Need to ck pressure at the tank port. That's what mine did when my pump went bad but the pump made noise. And it was low on pressure. This all Started with mine all if a sudden as well but now I have psi. I'm going to ck the pressure while lifting but it's to muddy to get to it now. Keeper posted on what you find. Also you will need a quick coupler for the gauge.
Bruiser, I can get access to some gauges. I spoken to a couple local mechanics, they have advise me to change filters first. In doing that, I discovered the inline filter that is currently installed is not the correct filter. A new correct replacement filter will be here this week. I don't think my issue will go away after this and will have to continue. One fellow told me he would consider a new pump cartridge. I think the pressure checks will be more beneficial. So, all that to say I still haven't fixed anything. Stay tuned. Thanks!
BTW, no noise from the pump. There is some cracking noise when the boom is being lifted, sounds like it is in a bind.
Well mine is fixed I had to use it to grade a yard and it started working. It must have been something under a valve. We loaded 63 dump truck loads of dirt to day and still working great. Mitchel I would ck your lift cylinders for a blown piston seal. The best way is to lift the bucket all the way up and take the top Hyd. Line off and have someone try lifting and see if its bypassing fluid past one side or the other. Or call me and I can better explain 913-238-6070 George