Hello truckers and family, Would someone be able to help me figure this out? Why my Freightliner FL 112 2003 Caterpillar C12 engine has only one oil filter? Why is the secondary disabled, it appears to me it has been factory disabled. Any input would be greatly appreciated.
Some of the 3176,s that were here had two filters side by side like that. The primary is a 1R1808, LFP4005 or 57792. The secondary filter is a bypass 1W8845, 51749 or LF777.
You can look up the microns of each. All of the oil that runs through engine is filtered by the primary unless a bypass opens. The secondary is a very fine filter, normally only has two inlet ports into it, and returns oil back to the pan. Only a small amount of the oil that runs through the pump goes through it.
The 777 replaced the big LF750B Luberfiner bypass filter. When the new trucks came out with those oil change intervals went from 8,000 to 16,000 miles.
You would probably need a nipple in order to install a second filter on you truck. I have never done that.
Things like that happen for different reasons. I have a Cummins with the 777 blocked off and a Spinner II mounted on the frame?