question for you guys, i have just repowered my 642 bobcat and have some problems. after about 10 min my main pump gets very hot and and then all the hydraulics start to whine and not work very good. they get so hot i cant leave my hand on them. i have a fan blowing on my oil cooler and i can hold my hand on the cooler and the oil filter. they get warm but not hot. i have changed the hydraulic oil and filter. thats problem one.....the other problem is when i push down for my boom it wont lift the front of the bobcat. it trys but its struggling. i can push down with my bucket and it just pushes the boom up. im thinking my my hydraulic valve needs to be rebuilt and have ordered the kit to do this. im wondering if somethings wrong with the hydraulic valve can that make my pumps over heat? when the machine is running its not laboring and the aux are not engaged. any ideas?
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Does the machine scream when you move it around? Some older models have a hidden filter that is easy to miss, it causes this exact issue with getting stupidly hot and making it not move well.
On top of the hydraulic pump, there may be a square block with a buch of hoses coming into it, the left side shold have 3 hoses, behind the fitting on the middle one is a filter. Like i said, not all modele have this setup, but if yours does, it could be the issue.
On top of the hydraulic pump, there may be a square block with a buch of hoses coming into it, the left side shold have 3 hoses, behind the fitting on the middle one is a filter. Like i said, not all modele have this setup, but if yours does, it could be the issue.
it doesnt scream cold, but when it gets hot it makes some good noise! i had seen that on other posts, but mine doesnt have that block.Does the machine scream when you move it around? Some older models have a hidden filter that is easy to miss, it causes this exact issue with getting stupidly hot and making it not move well.
On top of the hydraulic pump, there may be a square block with a buch of hoses coming into it, the left side shold have 3 hoses, behind the fitting on the middle one is a filter. Like i said, not all modele have this setup, but if yours does, it could be the issue.
What did you figure out? I repowered my 642b with a Kubota. One thing I noted was the RPM the new motor needed to run for max HP.. The old motor was quite a bit lower rpm. I lowered the RPM of the newer motor to match the old one.. The new one technically does not reach max HP, but it is plenty. I was afraid the HYD would not take the extra 800 or so rpm of the new motor.. Just a thought.. I am curios to what you found. Aaronit doesnt scream cold, but when it gets hot it makes some good noise! i had seen that on other posts, but mine doesnt have that block.
everything is on hold right now, the weather is crap and im very busy. i kicked it outside for the winter. i bought the seal kit from bobcat for the control block and when i get time i will rebuild it. i tried to run the motor at a lower RPM but the main pump still gets hot. im betting the main pump is wore out, but will have to see. give me a few months and ill get back on it!What did you figure out? I repowered my 642b with a Kubota. One thing I noted was the RPM the new motor needed to run for max HP.. The old motor was quite a bit lower rpm. I lowered the RPM of the newer motor to match the old one.. The new one technically does not reach max HP, but it is plenty. I was afraid the HYD would not take the extra 800 or so rpm of the new motor.. Just a thought.. I am curios to what you found. Aaron
