Priming a hydro pump...
 

Hello everyone, I put new seals in two hydro pumps, put everything back together, and the first trans worked like a charm... The second... not so much. Are there any tricks in priming a pump? How long can I run it with out damaging it with out it working?

The first hydro I made into a "little" tractor had a leak in the pump. I only discovered it 2 days from delivery. I have devised an electric "tester" that I mount on the top of the trans, and runs the pump with a belt. I've used this on four transmissions so far with good luck.

Thanks,
Kurt

Kurt

I've never had one fail to prime, first thing to check is that the charge pump cover didn't get put on 180 deg out. That's quite common to reverse.

If the charge pump cover is correct, then it's time to pull the charge pump cover and check the pin in the pump.

Last summer I delivered 2 tractors to Red Power. I finished them both with 2 days to spare. On my initial "test run" the 1206 I built leaked... um... um... what now. I bought a used pump off x-bay, and hoped for the best. I pulled the rear end, and swapped the pump the day I had to load for the trip.

After that, I had to come up with a way to test the transmissions before I painted them.

I was surprised how much horsepower it takes to run them. I tried a .5 horse, 1 horse, and finally, I'm using a 1.5 horse engine. It can only run it 1 to 1 ratio, so it's only turning 1750 RPM, but I can at least see if there are any leaks.

Kurt

I test them with a drill. The drill is not happy but it works. I like your rig.

Old trick I've used on Hyd systems, is to put a few pounds of air pressure on the resevoir fill.
I would be careful and not go much over a couple of pounds.
it usually works to "teach" the oil where to go Ha,LOL!