put a thumb on my excavator what to istall releif valve on the axillary valve bank how do adjust the setting or is it complicated thanks
Serial Number of the machine please - or at least the S/No prefix ........ Do you know what Part # of auxiliary valve you have installed..? There is more than one and specifically some are for high pressure single flow circuits for a hammer, others are medium pressure for attachments such as a thumb. Did your machine maybe have an attachment on it at some time in the past..? What does the manufacturer of the thumb recommend for relief pressure..?
6YM02078 part#107-6917 it had the bank on already don't think it was ever used I built my own thumb got the switchs and some stuff from suregrip
Loosen jam nut 4 and turn screw 3 clockwise to raise pressure counterclockwise to lower pressure. I would start at about 2200 psi to test your thumb. You will need a pressure gauge on the pump to test and adjust. Run about half throttle when checking pressure.
got 5000psi is that enough
Too much. That may be the main relief your seeing and not the circuit. Seem to remember them being in the 2500 psi range. Need to be able at have your bucket overcome it. Don't want to much as you can damage your thumb. Back out your screw until, as Mobiltech said your around 2000 ish and raise slightly from there
okay thanks for the info
5000psi in an implement circuit and you're going to start blowing hoses like it's going out of fashion, the hoses on that machine are only rated for 4000 IIRC. As Ben says are you testing the pressure in the thumb line or are you seein manin relief valve pressure. I'd crank that valve out at least a couple of turns before starting to check pressures and slowly work up to what you want. To be honest if the thumb supplier doesn't have a pressure recommendation personally I'd start somewhere maybe around 1500-2000 and see how much clamping force you get on the thumb. If it's not enough increase the circuit pressure a tad and try again. Keep going up until you are satisfied or you hit 2500psi, whichever comes first. Too much pressure and you could end up tearing the thumb mounting off the stick or buggering up the linkage.
sorry what I ment I have 5000psi gauge to test I was wondering if that was big enough
5000psi gauge should be more than enough. I'd still crank the relief valve on the thumb circuit back a couple of turns before starting pressure testing.