I have an older TMZ 34/19 lift.. I seem to have lost hydraulic pressure... Aa of the cylinders have recently been rebuilt...all of the solenoid valves seen to be working...I was useing the lift, cradled the booms, moved it and now it doesn’t want to raise the lower boom...the middle boom is slow and the oil heats up very rapidly... It seems to be bi-passing in the control block on the pump. I have removed the pump ( A gear pump) and cleaned and checked it and the pressure relief, still acts the same...
Do you have access to a pressure gauge? Oil filter changed anytime recently? Oil in good condition and tank full? Mechanically all the booms are free, pins/bushings not seized. If hydraulic outriggers do they function OK?
Thanks for the reply...yes checked filter, tank full of good oil and I was using the lift when it quit...I have low pressure everywhere all of a sudden like something is bi-passing
Did you check the bypass valve to make sure it was closed?
Oh yes...I have completely torn apart all valves, by-pass, pressure relief, electric solenoid, and all cyl. Have been rebuilt...after a month I have found the problem and repairEd it...it was in the rotation ( which worked fine), but under pressure the oil was bi-passing though the rotation solenoid...A small o-ring fixed it...thanks anyway
good to hear!
Yes, good to hear you resolved it. Curious, did you replace the o-rings in all the valves you took apart or just the o-ring in the rotation cartridge? Was the problem with that o-ring obvious? Torn, cracked, lost it’s round profile? Did you source a third party/generic o-ring or did you buy Genie? I’m refurbishing a 2002 TMZ 34/19 and am curious what general condition the cartridge valves were in when you inspected them. I haven’t got that far yet. Still cleaning rust, painting, replaced pins/bushings, limit switches, etc. I’m over the hump but haven’t done any maintenance on the hydraulics yet except for replacing some cracked hoses to the outriggers.
The hydraulics are very simple...I guess that is why it took me several tries to fix it...I replaced all the O-rings as I went through it...
I should probably just replace them all too. Where did you get the o-rings?
I purchased several o-ring assortments online and use the all the time....