hello all do you know how to adjusting HPV090 (komatsu pc 120-5 pump) hydraulic pump correctly? this pump have several settings like TVC valve, CO valves, NC valve anyone help appreciate
Before you try to adjust one of these beasts you need to know what all the terms mean. You can adjust the pumps on the machine if necessary but it is usually better to do them on a test bench. It takes at least four gauges to adjust one of these pumps. I used five most of the time. Two 6000 PSI gauges go into the output lines on the pump. Two 600 PSI gauges go into the test ports on the side of the pump. They are large bolt looking rods with a 17 millimeter hex head plug on the ends. As I recall they point down on this model of machine. I usually put a 600 PSI gauge in the pilot pump output also. The settings are done in order. Pilot pressure is done first on the pilot circuit test port. Jet sensors on the main control valves are set next. I usually put them so they show approximately 70 PSI with no functions on stroke, engine at high idle and system in H mode. You read these on the two 600 PSI gauges plugged into the pump control pressure ports. I then set the main reliefs to spec. Once those are set I adjust the cut outs to the same 70 PSI on the pump control circuits that showed when setting the jet sensors. After that you walk the machine for a couple of hundred feet to make sure it goes straight. If the swivel and travel motors are OK and it walks crooked you might be able to change some shims around in the servo piston caps to even it out some but the usual problem in those old systems is that the barrels the servo pistons ride in are worn out and need to be build up back to spec. At any rate if you can't get it close you have big problems inside the pump and you will have to tear it down to figure out what is going on. I've done lots of these and I'm afraid I might be making it sound either easy or so full of jargon that you might not understand. It looks like you have the manual so identify all the components you have to work with before you start plugging in gauges and twisting relief valve cartridges. More likely than not your pump and machine are badly worn and the best you can hope for is to make it usable for you. Good Luck!
thanks so much Mr.John C. I'll try to do this today and i reply to you result.thanks in advance