642b oil pressure light

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Dougiefresh

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Joined
Dec 24, 2010
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Hello just bought my first bobcat 642b. serial number on bobcat 504028341 on engine 46326F2470. The dummy oil pressure light comes on after running it for about 10 min. The oil is up to the full mark. I did continue to run it for about 30 min after the light came on and nothing happened to engine. Ran it at 25 degrees outside. I was wondering if anyone had advice on possible checks to do on the oil pump or is it just the sensor switch that might me bad. Any advice on this or service information welcome. I have the owners manual but no service manual. thanks.
 

skidsteer.ca

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Jan 20, 2006
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3,853
You need to get a pressure guage and install it pronto!
The light gets tuned on by the lack of pressure to the sender allowing it to ground the wire for the light thereby completeing the circuit. If the sender is falty or the wire insulaton wore through you can get a light when you should not.
I thing we have a manual for that machine here in the manual thread, it should have info on how to test to see ifyou have a real poblem or just a indicator light problem
Ken
 
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Dougiefresh

New member
Joined
Dec 24, 2010
Messages
3
You need to get a pressure guage and install it pronto!
The light gets tuned on by the lack of pressure to the sender allowing it to ground the wire for the light thereby completeing the circuit. If the sender is falty or the wire insulaton wore through you can get a light when you should not.
I thing we have a manual for that machine here in the manual thread, it should have info on how to test to see ifyou have a real poblem or just a indicator light problem
Ken
Thanks for the reply back. I am new to forums and looked through the threads but could not find any manual. If you or anyone else has a manual or any other information/pictures on how to test the sending unit that would be great. Also do you or anyone know where the sending unit would be located. Thanks a buntch.
 

under the bus

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Dec 25, 2010
Messages
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Thanks for the reply back. I am new to forums and looked through the threads but could not find any manual. If you or anyone else has a manual or any other information/pictures on how to test the sending unit that would be great. Also do you or anyone know where the sending unit would be located. Thanks a buntch.
Are you saying that you have an engine oil pressure warning light coming on or a hydraulic general warning light?
 
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Dougiefresh

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Dec 24, 2010
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Are you saying that you have an engine oil pressure warning light coming on or a hydraulic general warning light?
I think it is just an engine oil pressure warning light. I changed the oil and filter and light still comes on. when you are sitting in the machine there are two lights on the right side of the machine, the lights are side by side. the light that keeps coming on is the light on the left. i dont have a service manual yet but will be getting one. not sure if that light only goes on for engine oil pressure or other things? thanks
 

under the bus

Member
Joined
Dec 25, 2010
Messages
14
I think it is just an engine oil pressure warning light. I changed the oil and filter and light still comes on. when you are sitting in the machine there are two lights on the right side of the machine, the lights are side by side. the light that keeps coming on is the light on the left. i dont have a service manual yet but will be getting one. not sure if that light only goes on for engine oil pressure or other things? thanks
if it truely is an engine op light I would not run it at all. normally the sending units are 10 psi. You better figure this deal out soon or you may end up with a box of rox.
 
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