Filling Hydraulic System after pump rebuild

Sun Sep 01, 2013 4:50 pm

After much help from everybody on this site, I have the hydraulic pump all rebuilt from parts obtained from TM, and looking at the rebuilding instructions here. I have it all bolted back on the Cub (1959 International Cub Lo-Boy with fast hitch), with the pump hand filled with hytran oil as I put it together, and filled after bolted up and the gears turned over by hand to observe it's pumping action and get all the air out of it. I see that there are two allen wrench type plugs on the plate that bolts to the side of the hydraulic controller box. Each one in line with the incoming and outgoing oil tubes from the control box to the pump. These appear to be a means of filling the pump feed tubes with hytran before starting the engine? My question is, whats the proper method of filling the system with hytran before starting the engine? I haven't filled the reservoir yet either. :lost:

Re: Filling Hydraulic System after pump rebuild

Sun Sep 01, 2013 4:53 pm

If all goes well, just fill the reservoir, and with the tractor idling and the fill plug installed but loose, cycle the lever several times. That is the way it is supposed to work anyway.

Re: Filling Hydraulic System after pump rebuild

Sun Sep 01, 2013 5:39 pm

John has you covered.

Re: Filling Hydraulic System after pump rebuild

Mon Sep 02, 2013 8:35 am

The plugs are actually pressure test ports for troubleshooting iirc.

When I filled mine last spring after a complete rebuild I simply cycled the lever back and forth slowly and kept topping off the reservoir until the system was full and working.

Re: Filling Hydraulic System after pump rebuild

Mon Sep 02, 2013 3:53 pm

Matt Kirsch wrote:The plugs are actually pressure test ports for troubleshooting iirc.

When I filled mine last spring after a complete rebuild I simply cycled the lever back and forth slowly and kept topping off the reservoir until the system was full and working.


Thanks again everybody for your help on rebuilding this hydraulic pump. It worked as you told me. Filled the tank. Put the oil and filter in the engine. Turned it over several times with the crank starter and watched the mower deck move down since I had pushed the lever down. And then fired it up and it worked immediately. Worked the leaver several times to work the hydraulics back and forth and filled up the tank and she is off and mowing again. :thanx: :thanx: :mrgreen: :beer: