Fuel dripping on first start; then less, then stopped

[dagsurplus]

I started my new-to-me M1009 from GL; fired right up. Then found a pool of diesel on ground under bell housing. "Valley" under intake manifold wet with fuel but could not find source of dripping. After searching this great site, assumed it was bad throttle shaft and/or IP seals. In the multiple times I've started the engine in the past 3 hrs, I noticed that the dripping slowed and now has stopped, at least the dripping on the ground. I have two questions:

1) Could it be that the throttle shaft/IP seals had dried in the 2-3 yrs it sat (all fluids were drained) and have now rehydrated and thus, sealed? If so, other than watching for future leaking and putting the IP rebuild on the to-do list, is the truck drivable?

2) Is it dangerous to drive with a possible fuel leak on top of the engine?

Thanks in advance.

 

[Hasdrubal]

My fuel leak I had from the valley drain was coming from a deteriorated rubber fuel line near the CDR valve, it connects to the steel line from the lift pump on passenger side. Try putting a rag underneath the IP, you'll be able to see where its leaking from.

Lots of people have operated the 6.2 with a fuel leak in the valley, never heard of a diesel self-combusting.

 

[dagsurplus]

My fuel leak I had from the valley drain was coming from a deteriorated rubber fuel line near the CDR valve, it connects to the steel line from the lift pump on passenger side. Try putting a rag underneath the IP, you'll be able to see where its leaking from.

Lots of people have operated the 6.2 with a fuel leak in the valley, never heard of a diesel self-combusting.

Great tip on using the rag Hasdrubal; thanks so much, will give it a go. By the way, took truck around the block for first tour; fuel dripping that I thought had disappeared turned into semi-flood.

 

[Vhyle]

I'm not sure about your leak, but I definitely wouldn't worry about your truck blowing up from a fuel leak. I had fuel dripping directly onto my exhaust manifolds (injector drainback lines) for a while, and I never had issues. It simply doesn't get hot enough for diesel to just combust.

Now I'm not suggesting to drive it with a leak forever; obviously you should get it fixed if it happens again. But if you do have a leak, don't be scared.

 

[dagsurplus]

The rag diagnostic technique worked to perfection; showed dripping from under IP. Thanks again Hasdrubal for this practical approach to confirm problem location.

 

[Barrman]

Make sure it is the throttle shaft seal before you go pulling everything apart. There are 8 injector lines and any of them could be loose. The IP fuel supply line also screws in there and could be leaking. Then you have the hose from the filter to the IP. It is 1/4". I really could just be a loose clamp on that line.

The best way I have found to work on that fitting is this. Take a lawn chair pad, lay it on the drivers side of the engine/alternator. Lay on the pad and reach under the intake from the rear. Feel for anything wet. If it is the hose from the filter. Then with a 1/4" drive socket driver with a 1/4" or 5/16" short socket on it lay on the pad. Reach under the intake from the back until you feel the screw clamp. Remove it, pull the hose off. Remove the other end of the hose from the filter and put a new one on.

 

[dagsurplus]

Make sure it is the throttle shaft seal before you go pulling everything apart. There are 8 injector lines and any of them could be loose. The IP fuel supply line also screws in there and could be leaking. Then you have the hose from the filter to the IP. It is 1/4". I really could just be a loose clamp on that line.

The best way I have found to work on that fitting is this. Take a lawn chair pad, lay it on the drivers side of the engine/alternator. Lay on the pad and reach under the intake from the rear. Feel for anything wet. If it is the hose from the filter. Then with a 1/4" drive socket driver with a 1/4" or 5/16" short socket on it lay on the pad. Reach under the intake from the back until you feel the screw clamp. Remove it, pull the hose off. Remove the other end of the hose from the filter and put a new one on.

Thanks for the tip on using the lounge pad; will save some arm bruising. However, I used the rag technique suggested by Hasdrubal and it shows the leakage is from under the IP; way towards to front end of the "valley". Thus, I conclude it must be the IP or the throttle shaft that is leaking.

 

[Hasdrubal]

Like Barrman said, make sure you trace that leak in case its not the throttle shaft seal. It could very well be the input line from the filter or one of the 8 injector lines. Dry everything off as best you can, you should be able to find precisely where the leak originates.

 

[dagsurplus]

Like Barrman said, make sure you trace that leak in case its not the throttle shaft seal. It could very well be the input line from the filter or one of the 8 injector lines. Dry everything off as best you can, you should be able to find precisely where the leak originates.

Quadruple checked the leak location. It's not the rubber hose going to the IP; I can see that. I can see most of the steel line connections to the IP; no visible leaks there. I've narrowed the leak location to under the IP biased toward the driver's side; seems to be right under where the label is located.

Made some calls about rebuild; pump works perfectly except for the leak so I think a rebuild rather than exchange is best. Guy who seemed most knowledgeable is from E. M. Tharp, a diesel truck repair facility in Porterville, CA. The guy quoted $700-900. Anybody have any dealings with them?

 

[epitts]

Mine was leaking from the shaft seal and you could see it leaking. We took it apart on the truck and replaced the shaft seals, runs fine still and no leak.

 

[lindyp38]

how about a leak from the front......dripping from the front cross member? any idea where that might be coming from?

 

[phil2968]

Check the rubber lines to the fuel pump.

 

[Hasdrubal]

Could be the lift pump or the fuel lines, thats precisely where it leaks down to. Get underneath the front and do a visual inspection, it should be easy to pinpoint. I had a lift pump fail after 13 months, leaked where the two halves are crimped together. Do not buy a Carter!! Get an AC Delco pump.

 

[lindyp38]

Are u talking about the fuel pump? Autozone lists one for about 50 bucks? Thanks

 

[Abbylind]

Had the same problem(s) with mine. First was the shaft seals on the IP. Replaced the seals...no leak. Second problem was the lift pump. PITA to replace but after completion....no leak!

 

[lindyp38]

It was the fuel pump. Original one to the vehicle. Thanks for the help.