Hello, I'm considering buying an old bobcat 743. The owner moved it a few meter(towing), and after this there where some noise from pump area. He continued driving it for a while, but it got much worse. So now it's very noisy, don't even now if it's drivable anymore... Is it worth repairing, anyone know what could be the scenario, best and worse case? I would guess some seals blew when towing, and maybe that blew the pump when he continued using it?
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OldMachinist
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What kind of noise? Why did he have to tow it?
The first thing I think of on a 743 when someone says it has a strange noise are the u-joints that drive the pumps from the engine. If they fail completely it can do some expensive damage.
The first thing I think of on a 743 when someone says it has a strange noise are the u-joints that drive the pumps from the engine. If they fail completely it can do some expensive damage.
Thanks for replying!
I haven't heard the sound myself, he said the battery was empty and he had to move it somehow. And after this there has been some noise, seems like it's coming from the pump underneath the seat. And now he said it sound like the pump will come apart..
OldMachinist
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That sounds like the u-joints. If they fail completely and pumps are damaged the repairs could cost more the machine value.Thanks for replying!
What happens then, only the pump or the motors on each wheel as well?
antfarmer2
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Most likley just the main pump shaft but can do more like the radiator and oil cooler if it grenades just unhook the engine and slide it out pretty easy and a hundred bucks for ujoints and have a great machine
When you go look at it take a helper and a socket set with breaker bar. Lay on the pumps and you can put your hand on the u joint while someone rocks the engine back and forth just a little with a socket on the damper pulley. If the u joint is bad you will be able to feel the two halves moving differently. Doesn't take much rocking either just enough to take up any slack in the parts. If you can move it a quarter inch back and forth you will feel it if bad. You may even be able to hear or feel it just with the socket if it is really loose.
Another thing, if it was towed, it does seem to make the pump get loud for a little while, but it does quieten down.
I'd like to start the machine, see if there are any wild vibrations, that is a sure sign that the u-joints are failing.
If the noise is a high pitched whine, that could be air in the system, or the engine RPM was a bit low.
If it's an older machine, it may have a port block filter that get plugged and the pump can get really loud.
Thanks for many replies, will check more if I buy the bobcat
