JD 500C - Outrigger leaks down

[MontanaSteve]

Have an old JD 500c Backhoe. Replaced one of the lines that had split on one of the outriggers, and now it will drop completely to the ground after a few minutes, which it did not do before.

We've run it up and down a few times, hoping if there was some air in the system or something, but it continues to drop. Any hints on what to do to resolve the issue?

Thanks!

 

[JDfan500C]

Nice machine. I have the same one and I also started a post about them. The outriggers go down slow on my machine after sitting off for a while. But I have notices that after I had one rebuilt because the seal blew out it dosent go down as fast as the other. Now dose this happen while the machine is off or on?

 

[Oxbow]

Sounds like you may still have some air if it did not do this before the hose replacement.

 

[MontanaSteve]

Sounds like you may still have some air if it did not do this before the hose replacement.

What's the best way to try and bleed the air out?

 

[MontanaSteve]

Nice machine. I have the same one and I also started a post about them. The outriggers go down slow on my machine after sitting off for a while. But I have notices that after I had one rebuilt because the seal blew out it dosent go down as fast as the other. Now dose this happen while the machine is off or on?

This is with the machine off. Before the hose was replaced, it would take a couple of days to leak down. Now, it takes a few minutes. The only thing that was changed was the hose, nothing else. So, must still have some air in it or something even though we've cycled it a few times.

 

[JDfan500C]

To bleed air you have to crack the fitting until fluid comes out and bubbles stop. But something is telling me it's not air. We had to replace the same hose and no problem. You might have to rebuild it. I do suggest calling your local jd dealer and asking them.

 

[Delmer]

If the piston seal started leaking, that turns the rod into the piston, so that there's a higher pressure with the same load on the cylinder. That could have caused your hose to burst. Either that, or the valve has cracked, or the relief got a bit of teflon tape or something stuck in it?

 

[MontanaSteve]

If the piston seal started leaking, that turns the rod into the piston, so that there's a higher pressure with the same load on the cylinder. That could have caused your hose to burst. Either that, or the valve has cracked, or the relief got a bit of teflon tape or something stuck in it?

The backhoe had been sitting outside for years, and the hose was all weather checked, and it got crimped. It was fine, right up until we changed the hose, so I do think there is any bad seals or anything. We took the old hose off, put the new one on, and now it leaks down.

 

[workshoprat92]

The backhoe had been sitting outside for years, and the hose was all weather checked, and it got crimped. It was fine, right up until we changed the hose, so I do think there is any bad seals or anything. We took the old hose off, put the new one on, and now it leaks down.

When you put the new hose on did you flush the hose out to remove any contaminates from when it was made? When a hose is made the hose is removed from a spool and cut with an abrasive saw machine. A portion of this abrasive material and particles from the cut find its way up into the hose. new hose ends are crimped on and the hose handed to the customer. If you did not flush this junk out and make sure your hose was clean you may now have gotten a piece of crap stuck in your valve body. Always flush a new hose clean before install!


Does it leak down when the outrigger is down or when it is up in the stowed position? If the leakage is from the stowed position you may be able to stow it take ratchet strap and tie it stowed. remove both hoses and plug both ports on cylinder. remove strap and wait. if it creeps down its your piston seals. If not then prolly junk in valve body. To find the problem it is all about fault isolation.

If the leak down is from the outrigger in the down position do same thing but use bucket to hold machine up while you install caps. then lift bucket and place weight on outrigger.

 

[workshoprat92]

Oh also air will not cause it to leak down. Pressure is pressure be it air or hydraulic fluid. the only thing that can cause a leak down is a LEAK! Normally all one needs to do to bleed air out of the system is to operate the cylinder from stop to stop several times and it will self bleed itself. Even if you did have air in the system all you would notice is the action might seem spongy. Do some diagnostics and isolate the problem from the cylinder or the valve body as I have suggested.

 

[MontanaSteve]

When you put the new hose on did you flush the hose out to remove any contaminates from when it was made? When a hose is made the hose is removed from a spool and cut with an abrasive saw machine. A portion of this abrasive material and particles from the cut find its way up into the hose. new hose ends are crimped on and the hose handed to the customer. If you did not flush this junk out and make sure your hose was clean you may now have gotten a piece of crap stuck in your valve body. Always flush a new hose clean before install!

Does it leak down when the outrigger is down or when it is up in the stowed position? If the leakage is from the stowed position you may be able to stow it take ratchet strap and tie it stowed. remove both hoses and plug both ports on cylinder. remove strap and wait. if it creeps down its your piston seals. If not then prolly junk in valve body. To find the problem it is all about fault isolation.

If the leak down is from the outrigger in the down position do same thing but use bucket to hold machine up while you install caps. then lift bucket and place weight on outrigger.

Thanks for the tips. Haven't done much work with hydraulics, so am learning. Will try your tips and see what we can find.

Thanks again