Can anybody tell me the procedure for bleeding air out of the hydraulic pump and downstream system after replacing the pump discharge hose on the rear pump. I assumed that after refilling the tank and removing the diagnostic test port immediately after the pump the oil would gravity purge the pump and would then be able to safely start machine and start opening bleeder valves at the hydraulic cylinders to further bleed system...(this was suggested by cat tech). However no oil has passed thru the pump to self bleed it at this point. Thanks for the help.
Cat excavators of that time frame were notorious for not having the pump mounted lower than the middle of the hydraulic tank. Gravity just wasn't enough to get the fluid to fill the pump. I used to remove the cap and use some air pressure on the tank to force the oil into the pump and out the bleeds. I used my hand or sometimes put a rag in the fill cap and stuffed the nozzle in. You didn't need much pressure. About what you could hold by hand.
After keeping the the tank 100% full for a few hours it finally appeared to gravity bleed the pump. I killed the fuel and rolled the engine over a few times, then fired it up and it appears to be good. Thanks