I think pages 42 and 43 are the parts diagram for the unloader valve assembly. Both probably need a rebuild. There seem to be replacement parts from a variety of suppliers.
Coming back to this after all the parts came in. On the hydraulic unloader valve assembly, there are three ports.
One on the top that goes to the unloaders (leave alone)
One on the front (dead center) that on mine was open to atmosphere, now connected to tank pressure.
One on the bottom...
No, I know I won’t fix it by moving to another port.
I’ve already pulled the valve apart and tried cleaning it. It’s toast. I was talking about placement for the new valve.
And for the unloader line, it should go to that port in the middle of the square component on the crank?
That's what the searching of some casting numbers turned up, but I wasn't able to 100% confirm. Not bad for $100 then?
You mean the hydraulic unloader is on the bottom of the pump (connected to the crank internally)? If so, I'll get some line in place to activate that unloader. Sounds handy...
Just picked up a new to me Speedaire with a few markings on it.
I called up Grainger and they seemed to think it was manufactured in 1986. I'm unfortunately not able to find their catalog from that year to confirm.
The main label shows a Model 1Z781 (Non-Code)
The motor is a 120v/240v 1HP...