terramite T5D loader drifting down (won't hold backhoe up either)

[refixer]

Hello

First post. Just yesterday bought 1999 backhoe. Some leaks. Strong hydraulics but they leak down so fast my front bucket will dig in. Is this just the cylinder or maybe a check valve somewhere. Need help!! Book has nothing on hydraulic troubleshooting so please give complete advise like I'm an ignorant idiot on a backhoe near you

 

[muddstopper]

To check the cylinder, extend boom all the way and place on ground. Cyl must be fully extended. Remove hose from rod end of cylinder and plug hose only. Operate control valve as you would to extend cylinder further. If you see oil squirting out of cyl at the fitting, then cylinder is bypassing internal. Rebuild or replace cyl. If no oil comes out of the cyl. then it is possible your control valve is bypassing. This could be the relief, or it could be the spool. If relief is adjustable, then try adjusting to see if this helps.

 

[refixer]

To check the cylinder, extend boom all the way and place on ground. Must be fully extended.Remove hose from rod end of cylinder and plug hose only. Operate control valve as you would to extend cylinder further. If you see oil squirting out of cyl at the fitting, then cylinder is bypassing internal. Rebuild or replace cyl. If no oil comes out of the cyl. then it is possible your control valve is bypassing. This could be the relief, or it could be the spool. If relief is adjustable, then try adjusting to see if this helps.

Thanks Mudd,
I am going to try that only on the loader end lift cylinders. Those are the ones giving me a problem. I need to stabilize the machine while I dig with backhoe. Also need them to hold their position when driving around. I guess the same concept applies (extend cylinder all the way and remove & cap hose end). To do that, the loader will be way up in the air and need to be blocked up somehow, right?

Parts book showed a relief valve on both Hoe and Loader controller. But nothing about how to adjust them.

 

[muddstopper]

You dont have to lift the loader to test the cylinder. You can set the loader on the ground and instead of testing at the rod end, test the base end. Just remove the remove the hose at the base instead of the rod end. If the cylinder is bypassing one way, it will bypass the opposite direction also. And you can always just pull the clevis pin and extend or retract the cyl without moving anything. On the loader, you probably have 2 cylinders lifting the bucket, you will need to test both cylinders since they both work off the same valve at the same time and either one or both could be causing your problem. I suspect that the control valve for the loader also has a float function which lets the bucket float instead of having down pressure and that could be the source of your problem instead of the cylinders. I would test the cyl's first since its easy to do and doesnt cost any money to try. if the cyl test good, then move to the control valve, it might need rebuilt or replaced, or it could simply be the relief needs adjusting. I cant say how your relief is adjusted, but most reliefs have a acorn nut covering a allen head set screw with a locking nut. You remove the acorn nut and loosen the lock nut and use a allen wrench to turn the screw in to increase pressure relief setting and turn out to decrease pressure setting. Some valves have a preset relief that is not adjustable.

 

[refixer]

You dont have to lift the loader to test the cylinder. You can set the loader on the ground and instead of testing at the rod end, test the base end. Just remove the remove the hose at the base instead of the rod end. If the cylinder is bypassing one way, it will bypass the opposite direction also. And you can always just pull the clevis pin and extend or retract the cyl without moving anything. On the loader, you probably have 2 cylinders lifting the bucket, you will need to test both cylinders since they both work off the same valve at the same time and either one or both could be causing your problem. I suspect that the control valve for the loader also has a float function which lets the bucket float instead of having down pressure and that could be the source of your problem instead of the cylinders. I would test the cyl's first since its easy to do and doesnt cost any money to try. if the cyl test good, then move to the control valve, it might need rebuilt or replaced, or it could simply be the relief needs adjusting. I cant say how your relief is adjusted, but most reliefs have a acorn nut covering a allen head set screw with a locking nut. You remove the acorn nut and loosen the lock nut and use a allen wrench to turn the screw in to increase pressure relief setting and turn out to decrease pressure setting. Some valves have a preset relief that is not adjustable.

OK Sounds like something I can handle. Dug out a couple 12" pine stumps today. Loader sometimes would stay up for a while sometimes not. It does have the float down control but I'm not sure if it's working right. it might be dirty in the valve causing a float down when you don't want it to. It lifts machine up off ground great only comes right back down. Other cylinders seam to hold OK. Loader Cyl is 13 years old and No sign of ever being worked on. Thanks so much!

 

[J_J]

You might try and remove the load check valve for each spool and inspect, clean, etc.

If the machine is 13 yrs old, the cyl seals might be brittle and failing.

Does your relief come on when you get to the end of cyl shaft travel. If not, it is a good indication the fluid is going somewhere, and the cyl seals are the most probably cause.

If you install a hyd gage, you can monitor and trouble shoot the hyd system.

Hyd test gage set cost about $30.

You can install the gage in a tee in the IN port of the loader or the first valve in the series flow.