Howdy! 1997 Volvo A25C Ser # 5350V61047, has no pressure for steering while sitting, when moving the ground dependent pump kicks in and steers fine... Is there a priority valve that could be preventing flow from the engine driven pump to reach the steering valve? The truck is 500km away from me, trying to troubleshoot over the phone... Thanks, Greg
have you ruled out pump failure? is it tipping ok? there are a couple of things that could do it if the pump's are ok, on top of the steering valve "I think" is a dump valve used to return flow pressure when not steering, if this broke it could be constantly returning flow to the system, not the rams, there are also a couple of check valves above the front axle one either side of the engine, best way to check is to check pressures and see where you loose it I am not a fitter, only a lowly parts monkey, so I could be wrong, and hopefully someone with more knowledge will be able to help further
Thanks for the info, it dumps fine. It was steering fine the last time it got used about a month ago, thinking maybe that dump valve is just stuck? If it were closer i'd be doing pressure tests...
You will most probably find the steer pump is failed, its under the engine needing belly guards lowering and best to remove so they dont get damaged when testing, I think the pumps are Eaton units, there is an oil shut off control just under the hood n/s. tctractors
Okay so this oil shut off control under the hood is on the left side (when sitting in the seat) of the machine? Wonder if the operator shut it off some how? Would that disable the engine powered steering pump? Tricky as the truck is 500km away... Thanks, Greg
Greg, pop the hood up and look into the engine bay (injector pump side) if you look at the top of the hydraulic tank there is a lever that should have a stop control cable conected that stops the engine from starting, this lever hangs out from under the bonnet and cannot be missed, it shuts off all the oil feed from the tank, I would well expect your pump to be knackered as they fail fast, under the engine there is a few pumps Clock and Anti Clock rotation, I have forgotten the location of the steer pump off my head but I will double check if its a help. tctractors
It wont be the lever as you would have no tipping either, as tct said it will most likely be the pump itself, both pumps work the steering and tipping (hence my first question) but the rear pump on the pto housing has priority to steering, so I would start there, check the end of the main shaft on the pump when you remove it.
Thanks for all the info, looks like I won't be the one working on this unit, going to pass on the info and i'll let you know the outcome! Thanks again, Greg