Truck Repair: 98 2500 turbo deasel 12 valve, deasel, hot weather

Question
how do you adjust the idal durning hot weather the idal goes form 850 rpm to 500 rpm no oil presure orpower stearing.

Answer
There is a throttle adjust screw on the rear of the pump.But if it runs fine when cold,it might run higher RPM if you adjust it.I would make sure that the throttle was hitting the throttle stop at idle when cold.You need a 10mm wrench to loosen the locknut under pump & turn the screw out to raise throttle.Have someone hold throttle down(while not running) and you will see the screw on the rear of the pump going vertical.