OP
Smalljobs
Gold Member
All set, all seals off. It seems like I should remove the piston head so that I can install the blue lip seal from that end instead of having to force it over all the other grooves?
Jinma Backhoe Swing Cylinder Leaking
- Thread starter Smalljobs
- Start date
- Views: 14171
OP
Smalljobs
Gold Member
I cannot seem to stretch the blue lip seal over the piston head even after immersing in boiling water. What is the trick to installing a lip seal without the tool?
Bob Rooks
Elite Member
Does that piston come apart if you remove the nut on the rod? Some do. Another trick, after you have it boiling hot, is to use some steel shim stock around the seal lands. This practice is also sometimes useful when installing the piston into the cylinder. Saves the seal surfaces. A tool that will work well for that purpose is an exhaust tailpipe expander. http://www.harborfreight.com/catalogsearch/result?q=tailpipe expander
It looks like you got the better urethane cup seals too.
It looks like you got the better urethane cup seals too.
OP
Smalljobs
Gold Member
Bob, Tks. The piston comes apart, but at the other end.
wdchyd
Elite Member
Think "Tire Machine".....using slender smooth screwdriver and grease.....work fairly quick, no need for hot water....it'll drop right in with a twist
OP
Smalljobs
Gold Member
Thanks! I brought the seal and piston head to a local hydraulic shop this morning. He brought the parts into the shop and returned in less than a minute...all done! He would not accept any payment or even a coffee. Now I know where to buy fittings and misc help.
OP
Smalljobs
Gold Member
It's all back together with no leaks but the other one, #2, is now leaking out the same vent port. It never leaked in the past. When I removed the upper bar that retains the cylinders I noticed the upper stub bearing had lifted up allowing the #2 cylinder to be unsupported on the top. Now that's it's properly restrained, it leaked on every push stroke. Suddenly it stopped. I wonder what's going on here. I really need to use the BH this weekend and will avoid any end of swing where the relief valve hits maximum pressure. Yup, I have a gage on it, and it relieves around 2200 psi. Any ideas what happened to the #2 pistoni lip seal? It's never been repaired and the BH probably has less than 40 hours on it.
OP
Smalljobs
Gold Member
#2 Still leaks just like #1 did at the outset. The BH was stored outside under a tarp during the winter and I'm wondering if the two vents ingested enough moisture to damage the end of stroke areas. I found a lot of gunk and minor surface corrosion at the unswept area of #1 when I took it apart. It really seems strange that #2 never leaked and now it does. Maybe during the repair of #1, when I swung the hoe over one way and then the other, the piston head of #2 passed over the normally unswept area?
RonMar
Elite Member
Thats possible, when you had #1 out, the boom could swing past where #1 would have normally stopped the swing allowing #2 to be pulled into "new territory"
Bummer, but at least you know exactly what needs to be done to fix it
Well I have heat in my garage now, so maybe I will get around to paralleling my swing cylinders this winter
Bummer, but at least you know exactly what needs to be done to fix it
Well I have heat in my garage now, so maybe I will get around to paralleling my swing cylinders this winter
OP
Smalljobs
Gold Member
Ron, I think you're right. The hose still leaks too. Meanwhile I found the perfect mandatory Jinma backhoe accessory:
