So my rt has been sitting in the shop for a while. We stripped the drive spline on the 2 section pump that's mounted to the engine, not the main hyd. pumps. This pump runs the brake boost and swing in one sector, and the steering on the other sector. New pump, spline drive in engine gear housing, and new bearing for it, should fix it all up.
First new pump we got was wrong. Second new pump was right pump, but needed to make some adaptors for fittings etc. Finally, new pump installed, have swing and brake (front sector), but no steering (rear sector). Steering has always been weak on this machine, so I'm thinking we have something else wrong. Have hyd. flow, but no pressure at the front steering cylinders. Good flow at swivel, and someone has been at the orbital, so I guess its decided to give up the ghost. No change after replacing orbital.
There's a flow restrictor valve, with a pressure relief, between pump and swivel. I have flow coming out of this valve, but no pressure. I disassemble and the pressure relief has a lot of wear at the seat, and a fine shaving in it. So I go looking for a new pressure relief. Its a griesen, which has been bought out by parker. Grove is 13 days out on the whole valve, 26 days out on the pressure relief. Can't come up with a good part number for the pressure relief. But the hyd. shop has a generic adjustable flow divider with pressure relief, and it's only $100, so I buy it and some fittings and install. Still no pressure.
Pull the line off the pump and put my gauge right in the line. I know I've got no relief now, and the pump will just deadhead, but I decide to just bump the starter and see if the gauge even jumps. I don't care anymore if it deadheads, I'm ticked. I get nothing out of the pump for pressure.
So we repull the new pump, which is a pain in the a$$ to get out, the motor mount bolts have to come out and slide the engine and trans to the side, and its a pain to get at the fittings.
The guys finally get it out, and disassemble it. Call me over, and the seal on the back sector of the pump is out of place. Its kind of all goofy in there, because that seal is actually right by the gears. How in the world do the gears not chew up the seal? Well it doesn't get chewed up by the gears, because there's supposed to be a swash plate on the gear side, holding the seal in the housing. The front side swash plate was there, but the rear one wasn't in the pump. Gears were turning giving me flow, but with no swash plate I sure wasn't going to get any pressure out of that pump!
New pump is ordered. This one has been a little frustrating. I just couldn't see how the problem could be in the new pump, because it was giving me flow. Usually if you have flow, the pump will build pressure. So I went chasing other things all over that stupid crane. Pump to flow restrictor, through swivel, to orbital upstairs, back downstairs through the swivel to the twin steering cylinders, I had gauges put in all over that stupid thing trying to figure out what was going on.
Its kind of nice to have it figured out.