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Cat Man
Cat Man, Caterpillar Engine Expert
Category: Heavy Equipment
Satisfied Customers: 8952
Experience:  23 Years Caterpillar Engine experience.
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What is the oil pressure suppose to be on a 3406b cat idling

Customer Question

what is the oil pressure suppose to be on a 3406b cat idling at about 700 rpm
JA: What is the complete model and serial number of your machine?
Customer: i cant find the serial number it is 425 HRS 1987 PETERBUILT
JA: Are you fixing this yourself? What have you tried so far?
Customer: I JUST REBUILT THE ENGINE USED OLD OUMP I AM SUR IT IS THE LOW PRESSUR PUMP IT HASE THE RETARDER BE HIND IT
JA: Anything else you want the equipment mechanic to know before I connect you?
Customer: NO
Submitted: 1 month ago.
Category: Heavy Equipment
Expert:  Cat Man replied 1 month ago.
Thanks for asking your question. I will try and help you out.How much oil pressure do you have at idle? Is the engine cold or warm?
Customer: replied 1 month ago.
THE TEMP IS WARM I HAVE ABOUT 6 POUNDS AT 600 RPM
Expert:  Cat Man replied 1 month ago.
Thanks for the information.
Minimum oil pressure hot is 15 psi. If you have 6, that's too low.
I would first make sure the correct rod and main bearings were installed. Many times the crank has been turned and when normal sized bearings are installed. The engine will have low oil pressure.
I would also make sure none of the piston cooling jets have been knocked off.
If all of that's ok. I may try a new oil pump next.Please reply back if you need more help or have more questions. I am happy to assist.
Expert:  Cat Man replied 1 month ago.
Hey. I just wanted to see how things were going. Please let me know if you need more help. I am happy to assist. If my information was helpful, please leave a good or higher rating so that I receive credit. Thanks.