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Cat 3406 Low Oil Pressure
Posted 14 February 2011 - 11:16 PM
Posted 15 February 2011 - 12:35 AM
Posted 15 February 2011 - 09:21 AM
Check the oil pressure at the front and back of the block. Are they the same? Different?
Does it have Jakes? A cracked or inproper installation of the jakes can cause low pressure.
Did some one change oilpumps? The E and C oil pumps are the same but the E motor releaf spring and hold down are different. The E runs a lower pressure, but not that low. A good E will run 50-55 at 1800, a C should run 65.
57 mack h67
Posted 15 February 2011 - 10:13 PM
Posted 16 February 2011 - 12:07 AM
I would check the Jakes an the oil pressure (front an back of block as peterj suggested).But it sounds to me like there is tollerence issues either in your oil pump or your crank. Did the guy know you had oil pressure issues before he did the overhaul? If so why didn't he put a new oil pump in when he did the motor? How did the bearing inserts look when he pulled them, were they showing copper? I'm not trying to be a Monday Morning Quaterback I'm just trying to help. Now with that being said if we do a motor job either in shop or sending it out, if there is an oil pressure prob. we check all of these things including micing the crank for oil clearance. I would call the guy who did the motor job for you an run some of these questions that peterj & myself asked. As far as the oil leak? I would clean up the block where you see the oil an try to pin point where the leak is
Good Luck Ernie
Posted 16 February 2011 - 08:12 AM
I just noticed your address. West Texas Peterbilt is the place to go , in your area.
Posted 24 February 2011 - 11:41 PM
Posted 25 February 2011 - 12:02 AM
If you are losing oil at the jake brake housing, it would be easy to find. Pull the valve covers and watch while an assistant starts the engine. Why an assistant? They could also shut it off before it makes too big of a mess.
And don't let the Jake come on with the valve covers off!!! BIG MESS!!!
Posted 27 February 2011 - 10:53 PM
Posted 28 February 2011 - 04:13 AM
Posted 28 February 2011 - 11:30 PM
I did take a sample of oil to get checked out there was no oil in fuel.
Also if not already done you should check for fuel in the oil. Take a samlpe and send in for the check.
Posted 28 February 2011 - 11:57 PM
Posted 13 March 2011 - 10:30 PM
Posted 13 March 2011 - 10:43 PM
When the pan was down would have been a good opportunity to roll new bearing shells in. Did you mic the bearings for clearance at all? A lot of aged engines lose oil pressure internally due to bearing clearance which is a factor of wear from operation.
Well I have an update. Pulled the pan and replaced the the oil pump. Noticed that the old pump had some wear on the shaft bushings, I was sure this was my problem,put the new pump put fresh oil and filter turned her on and ran it for a while till the temp got to about 180. It has good pressure when truck is cold but once it gets to operating temp it drops to about 25#'s. any other suggestions? I am going to get the front stucture redone as it is leaking oil would it be wise to replace cam bearings in it? this has me stumped.
Going through life knowing considerably more about nothing than the next person.
Raining on your parade
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