Good Day I'm having a problem with my hydraulics on my 2010 JCB JS200 excavator. This problem started after my valve bank got reconditioned. I had the stick hydraulic cylinder that got damaged and some of the broken pieces got back into the valve bank so I had it cleaned and checked. I also had a new cylinder manufactured. After fitting the recon valve bank back into machine I noticed that the stick cylinder only moved in one direction (extend direction) until the end, but wont move back at all. All other hydraulic movements work 100%. it is only the stick that has problems. Boom up/down , bucket open/close , slew left/right. travel left/right all working 100% and fast. I swopped the 2 stick hydraulic pipes on the valve bank and now the cylinder closes perfectly but wont extend. I opened the spool on the valve bank that controls the stick to check if it moves with no obstruction in both direction. Spool is moving freely inside valve bank. I did check pilot pressure on 1 side of the spool valve controlling the stick cylinder and I get my pilot pressure of about 40 bar which is in spec according to manual. I have even connected the stick hydraulic lines coming from the stick cylinder to the bucket ports on the valve bank. the stick works perfectly in both directions then, proofing the stick cylinder is fine. Problem looks like it is only on the stick spool circuit. I would greatly appreciated any ideas that can help me fault find this problem. Thanks in advance
Perhaps a blockage in the control/ low pressure side?
Good day 2164 Reconditioned valve chests are allien to our group, we have reports of attempts but little sucess, most often these are scrap. Maybe you have some special process in Africa ? suggest you take a close look at what has been done to the valve chest. Kind regards Uffex
You try swapping the pilot lines?
Remove and check the holding valve and ARV on stick circuit
Good Evening Thank you Skata. Machine is now working 100%. I swapped the 2 pilot lines on the dipper spools on valve bank and dipper ram is working great and nice and fast to. I have learnt a lot from all of this. Much appreciated for your assistance and everybody that gave me advise. Regards