I just noticed that some outriggers on my Grove RT-60S are not holding well and slowly come down. Here's what I know: - They come down maybe 1/4"-1/2" per minute - There is NO oil coming out of them, no pool of oil under them My understanding is that the piston seal leaks, which equalizes the pressure between top and bottom oil, at which point it engages the counterbalance valve and as a result the outrigger comes down. Would anyone comment on my diagnosis. We can pull and rebuilt hydraulic cylinders in-house if necessary.
Yes, piston seals would be the most likely problem. If you have the time and somewhere you can spill a little oil, you could lift it up a few inches and carefully remove the hose (if it's not a steel line all the way) from the rod end where it connects to the counterbalance valve. Put it in a bucket and watch the drift and how much oil comes out of the hose. Only other thing I can think of is a problem with the counterbalance valves.
I agree with lantraxco , Most likely piston seals . Although leaking down 1/4 to 1/2 " per minute is pretty fast ! Are they leaking down from the stowed position or is this with them extended with load on them ? Or maybe both ? Give these guys a call for parts & seal kits . I deal with the Lebanon , IN . store . Seem to be pretty good people to work with . Give them the serial number on the crane and they can identify what you need pretty quick . Also tell them to send O- rings for the check valve mount . Have to remove it to get the lower outrigger leg & cylinder out . http://www.wppecrane.com/locations/ You have the box type outriggers similar to what we have on the Grove truck cranes . This is how I do it . HeavyEquipmentForums
td25C, thanks a lot. First things first: thank you SO much for the manuals. I am reading one right now. I mailed you something also. I am truly grateful. We have Walter Payton here too, I will give them a call. I have a lot of 40+ year old equipment and cylinder seals leak on many of those machines, due to hardened and cracked plastic. It is kind of typical. We pull out and rebuild those. I hope that modern seals will last longer than the original ones. I may just jack the crane up instead of digging a hole in the ground. I have a forklift that can jack it up. Your thread on cylinder takeout and repack is great -- this is exactly how my cylinders should come out.
Probably control valves leaking. Mike
That's cool ichudov ! The cylinder itself comes apart pretty easy on my rigs . No crazy torque value on the gland head or piston nut . Everything gets snugged down and is held in place with set screws . Little cumbersome getting the lower leg & cylinder out but probably not any harder than equipment you have worked on in the past . We are still run some 40 + year old equipment . I like it , no plans on changing anytime soon . Old school equipment kick's ass
OK, guys, I have some questions pertaining to outrigger cylinder rebuild. A) you would say that a rebuild of an outrigger cylinder should involve the following: 1) Change of all cylinder inner and outer (wiper) seals 2) Change of O-ring for the counterbalance valve 3) Change the hydraulic hoses proactively (I have a hose machine, hose and fittings) * Note * I have a pathological mistrust of old seals and hoses B) Should I also rebuild the counterbalance valve, is it rebuildable? C) These outriggers are equipped with removable pins. Unfortunately, holes for the holding pins, in two outriggers, have been ripped due to excess load on them. Can I just weld repair them?