KX080-3 hydraulics shut down engine

[rush creek]

I have a kx080-3 excavator when the bucket is open all the way the engine shut down same thing if I curl it all the way in. All filters fuel and hydraulic filters was change same problem I also feel that I'm not getting enough digging power. any help is be appreciated

 

[K5lwq]

When you say all the way down or up are you continuing to hold the valve open and that kills the engine or just the bucket being in that position kills the engine? When it dies, can you start it back up and leave the bucket in the position it died in and the engine will run?

 

[rush creek]

I continue to hold the valve open and the machine starts back up and if I holds it open again it will shut down.

 

[rush creek]

It only dose this with the bucket cylinder if I extend the stick cylinder it will not happen

 

[K5lwq]

I continue to hold the valve open and the machine starts back up and if I holds it open again it will shut down.

I was thinking that is what you meant. First of all I would not want to hold the valve open once the cylinders have reached full through. This dead heads the pump and can damage it to the point of no repair.

I suspect the relief valve is adjusted too tight and that is what is killing the engine. You need to get a pressure gauge and check the pressures on the system. The same thing could happen if you tried to lift to much weight. It should be set back within factory specs.

 

[rush creek]

I will check that tomorrow I should have a pressure gauge set somewhere . Do you happen to know offhand what the pressure should be

 

[rush creek]

I found my pressure test kit I will let you know the results tomorrow I think I will install a new relief valve also. Thanks again

 

[K5lwq]

Really need the manual for exact pressures but I see the working max pressure is 4000PSI.

 

[oldnslo]

Do you have a parts diagram or schematic for your machine? Curious since unless you have two pumps. All the the functions should be at same max pressure and cause engine to stall.

I looked at Messicks at the T version shows two pump or three pumps. Not sure if these where 3 difference options though

 

[K5lwq]

I saw the same thing. He really needs a service manual because pressures could be different at different points. There definitely would be more than one relief valve.