I am changing the seal kits on the boom cylinders on my PC-200 but the rubber o rings seem to be a lot slacker than the old ones. I am scared to try and push the parts together like this because it may hook and break. If I boil it for awhile will it shrink enough to be tight, or will it even shrink?
Boiling definitley will not help - at a guess, you have the wrong size orings & you need to get the correct ones. Were all the other seals in the kit OK?
Heating will definitely not help. Was the kit a genuine Komatsu kit or a "will fit" ..? If it was the latter was it a recognized brand or something from Joe Blow's Gas & Bait Shack..? I would suspect that the kit has been assembled using the nearest inch-size O-Rings to the original metric sizes, that would explain the slight size differences. Are things like the piston rings and the fibre bearings the same sizes as the old ones that you removed..?
Thanks. No its a genuine komatsu kit, but its a over seas version PC-200. The kit cost over $400.00 and only half the seals will fit. WTH.
Only thing I can suggest is to get a Part Number off the cylinder barrel (should be a plate or stamped there) take it to Komatsu and ask them what the correct kit is for that specific Part Number and generation of cylinder.
DMC - if you have fitted the seals, I would not not think you could credit the kit you have already bought. If the main seals are OK & it is only the orings that are wrong, it will be cheaper to just get the orings replaced. You could use genuine (part #'s will be necessary) or take the gland to a hydraulic repair shop & match the orings to the gland. Take your old seals with you for better comparison.
Thanks everyone. The seals that where leaking were the ones one in the outside. These seals were the only seals in the kit to fit. I just finished to change these and everything is back together. Everything is tight for now, I will see later when I go back to work. If it happens again I will take all the seals to a shop and get the same, I would have done this now but I need the machine for work and didn't have time.For now I guess the rest are garbage and my loss. O well.....thats life
Don't be so sure of that. If you toss them out they will sure as Hell be needed somewhere the day after you binned them.....
I'm a little confused about which O rings you are talking about. Do you mean the ones on the flanges hooked to the cylinders or are you talking about the internal seals in the gland and on the piston?
On my cylinder the o ring on the flange and between the outside ( where the bolts are) and the piston are the same.
There is an o-ring on the piston of a Komatsu PC200 excavator cylinder???
The pistons have the teflon compression rings with the expanders under them. There are seals inside the gland than look like a polypak which are real hard to put in. There is an O ring on the outside of the gland than seals the outside of the gland and the inside edge of the barrel. Those are usually tight. I was wondering if DMC is talking about the O rings where the hoses hook to the cylinder barrel and gland.
Sorry I said piston but I mean the sleeve (if you can call it that) before the piston. It looks to me like it just floats in the cylinder.Anyway, that o ring is the same as the one on the piece you remove first when you remove the bolts.This was where I changed the seals. Don't know the names of all these parts. Not a mechanic , just the owner/operator. Thanks