Hydraulic system not working after changing fluid

jeffgreef · Mar 3, 2016

Changed the fluid in the hydraulic box on my Super A, now the hydraulics don't work. What did I do- drain the pump so it needs to be primed? How do I fix?

DJ54 · Mar 3, 2016

Move both of the hydraulic control levers back and forth until it picks up the prime. Rock shaft my just move a bit at first, so move the lever back and forth until it becomes fully functional. Nosing it down hill a bit helps, if that doesn't work.

Just don't run for extended periods of time, or it will take the hyd. pump seal out. That's another good reason to check the engine oil level before doing a job, beyond the obvious. If the engine seems to be "making" oil, the seal is out of the hydraulic pump.

DJ54 · Mar 3, 2016

I forgot to ask if you removed the filter screen in the side of the hydraulic block. Should be on the left side, like 3" square, with 4 bolts holding it in. On my Super C's, the have a hyd. oil temperature sending cable coming out of it. Not sure if the Super A's had them or not, without looking. Remove the 4 bolts, and bump it, it should come loose. Just a fine mesh screen that can be cleaned with solvent. Having a few cans of carb./brake cleaner on the shelf is handy for this kind of thing. Spray, clean and reinstall. Gasket usually stays with the filter. Clean the mating surface, and give it a light coat of gasket sealer. If i haven't mentioned it, I prefer the Permatex 300 that comes in the brush on can. Seals well, but then releases well when you take it apart the next time.

Also with the screen removed, you can see the bottom of the reservoir, and see if there is any gunk laying on the bottom, and a good time to flush it out, while it's apart.

jeffgreef · Mar 3, 2016

Thanks DJ

I tried moving the levers, but not long, I'll do that again. I'm going to drain and fill twice since you can't drain the whole system at once, I'll do the screen the second time. Got the gasket at a local Int. dealer.

Thanks again

Oh- and I have no hyd. manual- how high do I fill it- to the fill hole?