hondaracer2oo4
Member
Hello all,
Everyone has been very helpful in the past, hopefully someone will know the answer to my new questions. I have a mid 60s Case 440 gas with the model 22 loader and model 21 backhoe. The story as best as I can tell is that the backhoe was digging out a stump and the operator didn't feel as though it had enough grunt, so they adjusted the main pressure relief valve up higher on the backhoe control valve. After this a hydraulic line blew and after that the hydraulic pump wear plate cracked in half. I wasn't aware of the part about the main hydraulic pressure relief being turned up. I obtained a new pump, installed it and was told that the blow off pressure should be 2500 read on the boom cylinder. Well when checked the pressure wouldn't go over 2000psi. I believe that this was because the booms pressure relief valve was blowing off. I have also since found out that the setting is supposed to be 1650psi. Well i put the new pump in and raised one of the stablizers and as soon as it reached the top of its stroke the new pump cracked just as the previous one had. I am wondering where I should be looking for the problem? Is the main pressure relief valve the culprit and not blowing off soon enough to save the pump or is the problem else where? Thanks.
Everyone has been very helpful in the past, hopefully someone will know the answer to my new questions. I have a mid 60s Case 440 gas with the model 22 loader and model 21 backhoe. The story as best as I can tell is that the backhoe was digging out a stump and the operator didn't feel as though it had enough grunt, so they adjusted the main pressure relief valve up higher on the backhoe control valve. After this a hydraulic line blew and after that the hydraulic pump wear plate cracked in half. I wasn't aware of the part about the main hydraulic pressure relief being turned up. I obtained a new pump, installed it and was told that the blow off pressure should be 2500 read on the boom cylinder. Well when checked the pressure wouldn't go over 2000psi. I believe that this was because the booms pressure relief valve was blowing off. I have also since found out that the setting is supposed to be 1650psi. Well i put the new pump in and raised one of the stablizers and as soon as it reached the top of its stroke the new pump cracked just as the previous one had. I am wondering where I should be looking for the problem? Is the main pressure relief valve the culprit and not blowing off soon enough to save the pump or is the problem else where? Thanks.