Dexta hydraulics problem

[millwood]

i put new O rings in my lift cylinder. replaced all other O rings i could get to, had a worn pin welded up that rides on the lobe on the lift arms, had the linkages adjusted changed the fluid put it all back together and my lift goes all the way up like its supposed to now but slowly leaks back down even with the engine running. before i did all this it wouldn't go all the way up and leaked down when the engine wasn't running.. what did i do wrong???

[Nick]

Hi, did you replace the hydraulic piston seal aswell?

[ianpdexta]

I don't have any direct knowledge of the Dexta hydraulics (yet) but it sounds to me like the valve, or may be the linkages that operate it, are sticking a bit. The valve plunger should slide in and out of it's bore in a sikly smooth manor.

This is based on the fact that when the engine is running iit will be pumping more than enough oil to make up for slight leakage so long as the valve allows it to.

Regards

Ian

[millwood]

i did replace the piston seals

[ericcullen]

Having the same problem. I don’t have the time to look yet. If you work it out please post your cure, perhaps it could be the same thing.

Kind regards

[Brian]

If it leaks down with the engine running it sounds like a linkage or valve problem. Try this check, raise the linkage to the top of its travel then pull out the auxiliary service button. If the lift stays up and does not move your problem is in the control valve/check valve area. If the lift still drops you problem is piston seal, ram cylinder safety valve or "O" rings.

What piston seal did you use? Some suppliers only supply the "O" ring and backing ring for the '000nd series as Dexta seals and not the lipped seal. These will not work unless you also use the later piston.