Hello Everyone, So I have this TC75 Terex excavator. A little over 300 hours on the clock. We started having problems with the dipper stick boom being under-powered however it could be made to work by activating another control simultaneously. Now the machine once put to work for a few minutes looses hydraulic pressure at the main valve body. The smaller valve body that controls, the slew, arm articulation and blade are fine and pressures there remain good. Yesterday I inspected the valve for the dipper stick. The valve was very difficult to remove when compared to the valve above it. I tapped the affected valve out with a brass punch and upon inspection that valve is bent. you can see the evidence of it getting stuck I am trying to locate a new one and any help there would be appreciated. I am also wondering if that valve, seeing how it acts as a fluid gate could be getting stuck in such a way that could allow significant enough pressure drop through that entire valve body to render the other controls on said valve body useless or if i could also have a questionable pump. My current plan is to correct the affected circuit in the valve body by replacing the bad portion and seeing what I have afterward. However if someone who has more experience than I repairing these which I am sure there are many cares to chime in here that would be great. Thanks in advance-Joe
If the sppol valve did not cause any internal damage, then you should not have a pressure drop. If all other functions are fine and no ghost movement in the other controls when operating the dipper control, then your control block is still good, but i would still replace the valve bank of the dipper. Your next question with the hydraulic pump I believe it is ok
The Terex TC75 is the same machine as a Bobcat 442, both built by Schraff in Europe. Does it have a sectional valve (held together with rods) or a unitized, one piece valve? You cannot replace just the spool, you will have to replace the complete unit.
Hey guys thank you. Forgive my terminology as I realize it may not be up to snuff. Spool Valve = the actual valve that moves back and forth in the body. So the Spool Valve has some wear on it but it is very slight , however the spool is in fact damaged enough to require needing to be tapped out of the valve block with a brass punch. Looking at the entire valve unit it does seem that it is unitized. I can imagine the entire unit will be quite pricey. You guys are going to cringe when I say this but what are the chances of running some 1000 grit sand paper along the spool valve to get it to slide easier in the body and temporarily work better? I know its not ideal and certainly not a fix just a temporary solution so I can move the machine to a better location to be worked on while I wait for parts to arrive. Just a thought. Does anyone have a preferred supplier for parts such as the valve block? Cheers, Joe