My 70D handles a 5' heavy steel bush hog with ease. It raises and drops properly, and I have set the metering screws properly for slow raise & drop. But it's always had a tendency to very slowly sink until the load is sitting on the ground. Doesn't matter if the engine/pump is running or off. It's annoying to have to jog the lever every minute or two to reset the bush hog height...
There's no oil leaking anywhere. So it has to be an internal leak back to the reservoir. After perusing the Hydraulic Equipment JD manual, it appears there are basically two possibilities: a leaking check valve (easy), or the cylinder's piston/rings are worn (not so easy!).
I will check the valves to see if the balls are round and smooth, but have the uncomfortable feeling that I'll need to pull the entire lift assembly (and drain the 7.5 gallons of gear oil from the transmission case) in order to get to the hydraulic cylinder.
Looking for hints/tips for anyone who's done this before...
thanks
Charles
There's no oil leaking anywhere. So it has to be an internal leak back to the reservoir. After perusing the Hydraulic Equipment JD manual, it appears there are basically two possibilities: a leaking check valve (easy), or the cylinder's piston/rings are worn (not so easy!).
I will check the valves to see if the balls are round and smooth, but have the uncomfortable feeling that I'll need to pull the entire lift assembly (and drain the 7.5 gallons of gear oil from the transmission case) in order to get to the hydraulic cylinder.
Looking for hints/tips for anyone who's done this before...
thanks
Charles