Piston not working in one direction any more
 

Hi Guys,

Hopefully someone can point me in the right direction on this problem.

I was using my excavator on Sunday, and after a while I noticed the bucket was stuck so I manually moved it and it worked again, then not long after I tried shortening the piston but wouldn’t move tried other way but that worked but it will not shorten at all under hydraulic power. And I can now manually move the bucket piston, where the other pistons are locked solid to manual moving.

The piston, pipes or oil cooler was warm but not hot. Cannot see any noticeable leaks and all the other pistons are working as intended.

It’s a Magom HRC Excavator, pump and pistons.

Thanks in advance.

Ian.

Re: Piston not working in one direction any more
 

Ian, i had the same issue with one piston.....was leaking past the internal seal but not coming out the end. replace seal, it working now.

Re: Piston not working in one direction any more
 

Hi Rob,

That’s what I thought might of happened. Guess I’ll have to strip it down and replace the seal(s). Will regular rubber O seals work? Or does it need to be something specific with it been in contact with hydraulic oil?

Ian.

Re: Piston not working in one direction any more
 

Is the cylinder the one that Magom makes? If you find an aftermarket replacement, that should work just fine or maybe order some extras from them.

Re: Piston not working in one direction any more
 

Any correct size oring will work, only thing you have to be concerned (aside from correct size) is if it is acceptable for oil applications. Black is usually oil application.

http://www.mcmaster.com/#o-rings/=1050a31

Metric sizes also.

Re: Piston not working in one direction any more
 

Most low cost O-rings are of Nitrile, no problem with oil

Re: Piston not working in one direction any more
 

Thanks for the answers guys.

Re: Piston not working in one direction any more
 

Quick update guys.

Magomhrc sent me some replacement o rings which arrived just before Christmas and I got round to fitting them last week. So now up and running.

Re: Piston not working in one direction any more
 

This may be a sign of contaminants flowing inside the circuit. The more contaminants = less room for oil which makes more pressure and in the hydraulic world pressure creates heat. The hot oil can cause seals to harden, making them lose their suction, resulting in leaks. This is why you need to changes your oil frequently and change the filter frequently. If your cylinder doesn't move, the barrier that the piston rod is attached to may have worn out.