We have a CAT 336 with a 9.3L engine. We keep getting fuel filter restriction event codes about every 150-200 hours and end up swapping filters. We only run CAT filters, approx. 600 hours ago we drained, flushed and refueled the unit. We aren't experiencing this in any of the other units being fueled from the same source. We've cut open replaced filters and aren't finding anything obnoxious in the filter media. Replaced the inlet and outlet fuel pressure sensors as well as the check valves in the priming pump. Low pressure fuel readings are within specs from the testing we have performed so far. We are going to try recleaning the tank and fresh fuel when we can get our hands on the unit again as well as tearing down the filter head to look for obstructions but just curious if anyone has seen this issue in the past and can offer some advice on a direction to head.
Have any of the old fuel filters ever been cut open.? If so what did the material that was plugging them look like.? That would be my first suggestion. If you want a detailed look at the fuel system you will need to supply a machine Serial Number.
You did change this one, too? If it has one?
Thank you for the response, as stated we've cut open the filters and they look to be in good shape, nothing obnoxious. We have a set to cut open today with 150 hours on them. Ill post photos when we get them opened up. SN# is TZA10080, I do have SIS and have read through the fuel system theory of operation. But maybe im missing something. Low pressure fuel is reading approx 100 psi with approx a 2 psi difference with new filters. When it trips the event we are seeing about a 11 PSI differential across the filters. Also you may know, i noticed in the screenshots from the technician ET notes the % of filter life used. Is this calculated by running hours or pressure differential?
Does not have an inline. It has the fuel water separator then 2 spin on fuel filters
Never mind, then.
To the best of my knowledge filter life is calculated using pressure differential. Have you downloaded a Product Status Report from the machine recently.? I'd be interested to see one if you have it available.
We have not downloaded PSR from this unit yet. We are still getting acclimated to using ET. We will make it a point to download it next time we get called out to the unit.
Wanted to post the UPDATE to this issue. We suspect to have found the culprit. New technician hasn't been installing the small center seal on the filter head when replacing the fuel/water separator. We suspect that is allowing the 10 micron filter to bypass sending unfiltered fuel to the 4 micron secondary and tertiary, causing filter pressure differential on the secondary/tertiary fuel filters prematurely and throwing the "fuel filter restriction" code. We have addressed it and in the current "find out" stage. If it doesn't cure the issue ill be back to update and ask for any other input.
A common occurence on water separator elements and not just on that model of engine. Fingers crossed it is the root cause of your problem.