Hi All, I'm a new member and I'm hoping that someone here might be able to help with a problem that we're dealing with. We have a case 530CK with the 32 backhoe. The cylinders have all been rebuilt and the valve body came out and was cleaned and put back with new o-rings. All functions work fine except the boom lift. I get very little pressure in the hydraulics and the engine doesn't load up. If I hold the stick down and deadhead another function I get full pressure and the boom comes up. As it stands I can barely get the boom up, let alone lift a bucket of dirt unless I use another function at the same time. I can't find a hydraulic circuit drawing anywhere but I'm wondering if there could be a problem with the regen circuit or if it's something I'm not aware of. Pushing the boom down makes good power and can easily lift the machine off the ground. I know this is an odd ball question but I'm getting desperate. I need to put the machine to work in two weeks and I have no idea what to look at. Any help would be greatly appreciated! FWIW, all filters have been changed, fluid has been flushed. All other functions produce full pressure and I can hear the pressure relief valve squeal. This is the only direction in the only function that has problems. Thanks All! Joe
Welcome to HEF @JLambert I can't, at this point offer any real specific advice. However, there are two valves listed for the 32 backhoe which are very different. Can you tell us which you have? D36122 or D30776? This will be a good starting point.
I have the 30776 valve. Thanks for your help!
Two things only come to my mind here, the secondary reliefs & the check valve/restrictor in the lower fitting port. Have the secondary relief pressures been tested with a hand pump after the rebuild? Could their original locations have been mixed up during the rebuild? Is the check valve in the proper port location?
At this point I'm thinking that anything is possible. I have not checked the relief valves by hand, is there a procedure? One thing I have noticed is that on all other functions you can hear the reliefs humming when you deadhead a cylinder while on the boom up it just never builds and I don't hear the relief. The flow restrictor definitely went back in and while it's possible I put it in the wrong port I don't think I did.
I take it you don't have a service manual? If not, I do have some hydraulic info on PDF. I cant upload it as the file is too big. Start a conversation with me (private message) & advise me of your email & I'll send it to you.
Probably something not assembled right in the valve but could be loose piston on the boom chylinder
You're thinking it could be bypassing right at the cylinder? I don't think I have rebuilt that cylinder yet but it doesn't leak down very quickly, (several days at least for the main boom to come down). Thanks!, Joe
I usually advise the to check the cylinders first in hydraulic issues..... but thought you already had it covered.