Stabalizer Creep/Drift

[trex2]

I'm somewhat new to heavy equipment, so please forgive the question. I use a 1997 Fermec backhoe. It has about 2200 hours on it. When the machine is parked with the backhoe stabilizers up, they will drift down after a period of time. Is this becasue the hydraulic system isn't "charged" when the machine isn't running? Overnight the stabilizers will creep down to about 1/2 to 3/4 down from full up position. Is this normal? Thanks in advance for your responses.

 

[cat320]

Mine does the same could be an inner seal because mine does not leak but just drift down one more than the other.There is nothing wrong the only thing is if you park next to something that you wish not to have the stablizer hit you have to park away from other stuff.

 

[Ross]

Haven't worked on a 1997 Fermec backhoes either. Mainly CAT428's and JCB 3CX sitemasters here. The odd CASE Backhoe but lets not talk about them. :sleeping

I wouldn't worry about it at all.

Is this becasue the hydraulic system isn't "charged" when the machine isn't running?

I don't know anything about that statement.

The busness end of the hydraulic system is sealed and shouldn't drift any.

Backhoe stabilizers or landing legs. They take a good bashing during use.

Probably be the Piston seals in the ram's like CAT320 said :thumbsup

Could be an internal problems as Ive encountered machines with lock out valves on the landing legs to stop any shock forces from being trasmitted to the control system. This is hyper-productive as it blows the piston seals over time. Cheaper than replacing shock relief valves though

Most operators ive dealt with normally drop the legs down after a shift because of the drift problem.

Sorry but i cannot give you any direct advice as i have never worked on that machine.

Ross

 

[surfer-joe]

It's likely you have a seal or other problem inside the cylinders that is allowing the oil to transfer from one side of the pistons to the other. Good advice to not park near anything you don't want the stabilizers to creep down on and damage. Been there, done that!

Worse news is that you may have a problem inside the control valves for the cylinders. May be a scratch or a cracked bore, maybe a piece of seal or dirt or other foreign object obstructing the spools from closing properly.

In any event, it's not a good idea to ignore this, as the creep does indicate you have a problem inside your hydraulic system. Hydraulic problems do not tend to repair themselves, but, like Cancer, spread into other components of the system and eventually cause big and costly repairs to become necessary. Better to check it out now. After some initial system checks, I'd start with the cylinders; check for scoring, bent rods, damaged seals and pistons, possible loose retainer nuts for the pistons.

Good luck!

 

[Countryboy]

Welcome to HEF trex2! :drinkup

 

[NateV]

My dads drop down some but not to almost 3/4 overnight. They problaby only move less than a foot or so over about a week. I think you should problaby just put them down when you park it.

 

[tuney443]

As long as your cylinders aren't leaking externally and have the strenghth to lift your hoe and maintain it there,don't worry about it---happens a lot--nature of the beast.

 

[trex2]

Thanks for the responses and the welcome :thumbsup It's good to know that this appears to be a fairly common thing. The stabalizers do support the machine when it is operating.

 

[trex2]

As long as your cylinders aren't leaking externally and have the strenghth to lift your hoe and maintain it there,don't worry about it---happens a lot--nature of the beast.

What if the cylinders were leaking? What would be the diagnosis and the cure? I just want to know what I should look for and anticipate. Thanks.

 

[cat320]

If they were leaking then you would have to have them re-packed and if you don't have the right tools can be a pain to do .

 

[544D10]

They can also leak if they cylinder gets scratched from rocks or whatnot.

 

[Xcopterdoc]

This is something I deal with on an almost daily basis! Drifting stab cylinders and drifting boom/dipper/crowd cylinders overnight.
Bottom line, they should'nt move.
If there are no external leaks, then it's in the cylinder or the valve body.
If the cylinder, it will be on the piston side not the gland seals. The valve body, it will either be a load check with grit in it or in the extreme cases a crack internal. Some of the old machines were of the multi sectional valve bodies and all you had to do was rebuild or replace that section. Now adays they are going to be a modular valve body and you repack, hope for the best or replace the whole module.
Some older machines have a valve body that is only common to both stab cylinders.. if both leak down, I would look there. Of course, don't discount the fact that you may have more than one problem. When one is fixed, it may lead on to another! Good luck and happy hunting!

 

[glsahl]

i'd agree with xcopterdoc.if both drift,it's unlikely you could've damaged them both,equally.check or relief valves with dirt,weak or broke springs,pitted seats.it's a common problem in jd,or new holland hoes.