FUEL LEAK, CUMMINS 98 12V, ABOVE THE STARTER AND BELOW THE FUEL/WATER SEPARATOR...HELP!

Don't feel around for a leak. It's very dangerous. A pinhole leak in a high pressure fuel system can inject fuel into your hand. It's very painful and this type of injury often results in amputation.

Nah, he's on the low pressure side, well away from the injector lines -

10-15 psi at most. The only danger there is getting your fingers a little oily :)

As to the problem itself, it could be a rotted-out section of fuel line itself, though that usually manifests as an air leak, causing very poor/rough running. The fittings on the fuel filter canister (particularly the heater element) have been known to leak, as well. A technique that works well is to wash the area down with degreaser, let it dry, then blow a little talcum powder around the suspected area. The talc will readily show the tracks of any leak, leading you right back to the source.

If you have the OEM fuel filter, you might want to make sure the old gasket isn't still stuck to the housing from the last change. The other thing that happens on 1st gens is the rubber return hose cracks. I have both on 89 and a 00, so have run into some of these problems. If its the filter gasket, you'll find the time after it blows out on the road. If it's the return hose, you might have hard start or other performance troubles.

joemyers

I know it's all low pressure before the injection pump but I get nervous when people say they are going to feel around for a leak anywhere near high pressure systems. It's possible the leak is in an injector line spraying fuel into that area. It may not be likely, but still possible.

Thanks for all the replies. I got out this morning and drove it hard and stopped after every few miles to look for leak, but only thing I came across was a little film of diesel around where the fuel/water separator attaches to the mount (guess it's screwed on?). How do I tighten it?

It was NOT enough diesel to suggest where all the diesel came from. Saturday I found the starter drenched in diesel and it dripping from the bottom of the bell housing. This "film" was small in comparison. I will mention that before I degreased and cleaned the area Saturday I cracked open the fuel/water separator and made darn skippy it was closed firmly. Wonder if it hadn't cracked open under vibration and that's where all that diesel came from?

Note: I did inspect the rubber fuel lines that run around the area and they were never degreased/washed and have always been dry as a bone. It would suggest they haven't rotted yet...but I'm no expert obviously.

Where is the fuel filter on my 12V? Inside the fuel/water separator? Thinking it might could use changing.

Randolf

Yep. How long has it been since you changed it? Anywhere between 10K and

15K is the usual interval.

Tom,

I've never changed the fuel filter on mine. I got it with 120k and now it's at 170k. No fuel filter change. Maybe it's time???

I did inspect the rubber fuel line piece behind the filter and up against the block. It kinda looks like it's in the process of cracking. When I drive to see daddy-in-law this weekend I will employ his help in replacing both the filer and that stupid rubber line.

How do you tighten or remove the filter/fuel/water separator????

Randolf

If you cange it and haven't done it before and it has the old style connector on the bottom of the filter can disconnect it first so you don't mess up the wires, and when moving the probe plug to the new can, be careful, as it is plastic and although sturdy, you can break it. Clean the probe electrodes. Oil "O" ring before screwing it back on. Also oil the filter can gasket(make sure the old one is off). Don't overtighten the new can.