Hey guys, purchased a kw t 300 few months ago, it had a digger body on it, we pulled digger body off an we put our auto crain service body on the truck an hooked it up, well we left the the front bumper on the truck due to it has a braiden winch in it, we left the tandem hyd. pumps on the truck, one is a big pump an one is a smaller one, the bigger one ran the auger an the bumper winch, an the smaller pump run the craine, so basicly we took the hose that ran the auger an looped it back around an back to tank. an the outrigger control valves we reinstalled to this body from the digger body so I can have hyd out riggers down the road, so I replumbed the hyd pressure line back into the inlet of the valve an the outlet went to my auto crain priority valve an threw it to the crain like before. well we got it to opperate the craine but after a while the oil will get hot an pressure will drop off, then I have to idle the truck up more to get pressure up more then itll go back to working, im sure with not having the correct pump that puts out the 8 to 9 gallons per minute has a lot to do with it, but I don't wanta pull these bigger pumps off due to possibly adding an hyd air compressor or other stuff down the road. also the auto craine priority valve that builds my opperateing pressure (2200psi) an the valve has an inlet press. an a electric solinod with a port that returns to tank an a pressure outlet that goes to craine, an when solinod isn't powered it dumps more oil back to tank, an when its powered it sends more oil to craine to give more psi, so basicly I have the solinod powered up at all times while using the craine, (not sure if its hurting me or not) we left the altec circuit board an fuses in the cab were they were used before the body swap. ive figured out how to wire my 8 function remote into the altec board to get the truck to crank up by the remote, hadn't figured out how to shut it off tho, but I couldn't shut it off from digger body either tho, had got to looking at the electrical relay an board in cab an noticed that the relay was unhooked, ( im guessing this was the shut down function) an I found that the throttle potentiometer switch from digger body ran all the way to the circuit board. but the auto craine high idle function isn't floatable like the altec foot pedal potentiometer, so when the auto craine remote is flipped to high idle it idles the truck up to 1000 rps. well ive contacted a altec tech representative an he didn't really have any information on the older digger (d945b) tried looking online for wireing lay out for the altec system but hadn't found nothing, when I did talk to the altec guy an toldem bout my hyd heat issues he told me that he though the digger hyd pump put out 11 gallons a min an my auto craine only needs 8 to 9, so he advised installing a adjustable hyd flow control valve. not sure if it ll work for my issues any hyd goo roors out there to adivse me here.
Not enough information, too vague and confusing to give any sort of logical answer. I am guessing the priority valve you are talking about may be converting an open center system (gear pumps?) to a closed center setup on the crane, but it's just a guess. Couple things you can do, first drop the engine down to idle, less revs is less oil, less oil dumped across the flow divider at high pressure is less heat. Another idea would be to use a two section gear type flow divider, the benefit of this is you split the pump flow in half, and dump one half back to tank, but it's driving the gear on that side of the divider, essentially putting the power back to the other side, so it only takes roughly half the pump pressure to give you full pressure to the crane. Again, less heat.