jdschwass

Hey'all,

I have read a bunch of difference people's experiences with fuel leaks, but I would really appreciate a second opinion. 1993 12 Valve Cummins Engine with VE pump in my 82 Crew Cab 4x4.

Drove about 15 miles over to the shop to get tractor tire fixed up today. I made it about 2 miles back before I smelled that sour diesel. I hoped that someone before me had left it behind. The engine kept running, so I kept driving, until I got to some road work, where I idled for 30 seconds before the flag man told me I was dripping "water". After confirming it was fuel, I drove the rest of the way home as swiftly as I could without making any stops. I could see the tire tracks of diesel behind me. I think it must have cost me half a tank. I had to be light on the pedalto prevent it from bucking from lack of fuel.

Getting home, I flipped up the hood to inspect further. I have an electric lift pump, so I had my wife turn the key while I watched. There is a fuel fountain coming from the back side of the injector pump, shooting upwards and towards the block, and another stream flooding down from the bottom of the pump.

I was thinking it would most likely be the return line... is there anything else that could produce that much flow without even turning on the engine? It's so bad that I cant stick my head under to look up and see where it is coming from.

That's my story. Appreciate your thoughts.

Thanks.

Sheep Herder

Well since I've been messing with my pump a lot lately, I would guess it's the big oring between the rotor head and main pump.
I would try to dry it off the best you can, then get a little mirror while someone turns the key to try to find the source.

I bet you will have to pull the pump for a complete reseal.

jdschwass

A mirror is a good idea. I can't imagine how an oring can lose this much fuel. Not saying you're wrong, just hard to picture it. The entire side of the truck, firewall, front and back tire, and underside are coated with fuel. Must be losing half a gallon a minute. Ripping apart one of these pumps is one thing I havent had to do before... was hoping I wouldnt have to either!

Thanks for your help.

oliver foster

Wow that sounds like quite the leak.
One question....What pressure is the electric fuel pump running?

If it a pump that was designed for a P-pumped 12V or 24v it might be running at a LOT higher pressure then that VE pump wants.

Which would blowout all sorts of seals in the pump and make it leak badly.

Might want to check the oil dipstick and make sure you are not leaking tons of fuel into the engine through the VE pumps front seal, into the timing case and into the oil.
Running the motor overfilled with thinned out oil is not great for it.

jdschwass

I honestly have no idea what the lift pump pressure is, I dont have a gauge or anything installed. The pump was installed on the engine when I got it, and I have been driving it like such for over 10 years now with no issues.
I will certainly check the oil to make sure it isnt contaminated.
It really is quite the leak though. The stream of fuel coming from the back looks as if someone just disconnected a fuel line and then started pumping fuel through it. Fun times.

Thanks again.

oliver foster

Supply fuel line tight at the pump?

jdschwass

Supply line is good. I just got brave and crawled under while the lift pump was running. It appears there is a jet of fuel coming out on the back side of the injector pump, towards the front, but fairly low down. I still need to locate a mirror to see if I can get a better look, but either way, the stream is coming from the side of the pump, which I assume means I need to pull it out regardless.

kensmachine

advance piston oring bad you will not be leave how much fuel will leak out of there. pump off to repair ken

jdschwass

Looking at a diagram, I would say you are correct. It looks like a pretty simple repair once the pump is off. Just need to find the correct oring. Is there anything complicated about it?
Once pump is off, is it stupid to just fix the leak? Or should I be doing an entire overhaul of the unit? I dont really know the history and what has been done in the past. It works great, I know it has been tuned, no other leaks, but also has 300k miles on it.

Really appreciate all the feedback.

kensmachine

I would just do all the seals I think you will find that the all the o ring's will be hard and flat. other things to look at with the apart are the head and rotor springs when I worked in a fuel injection and turbo shop we never put the old H&R springs back in any VE type of pump just two many of them come in with broken springs. they will run just fine with broken springs till the springs brake down to where the eat the pump up form the in side. check the throttle shaft and bushing if its the old brass 1 change it to the new updated one witch is steel. Ken

jdschwass

Great info, appreciate it. Thankyou.

Just about got all my lines pulled and getting ready to pull the pump out. I will plan to tear the pump right down and replace the springs once I can find a source for parts.

jdschwass

Found the smoking gun... finally got the pump out of the truck. One of the two bolts on the advance piston cover is backed off, and the oring is broken and extruding out of the opening.

I guess my question now is: the oring is green, so does this mean is has been replaced before? If that is the case, should I still tear this thing apart? Or do I just fix the oring and drive on assuming that the rest of the seals have been done. I am not aware of any other leak spots, and it ran great until this oring finally gave out.

I guess this explains why the leak was so bad!

Sheep Herder

In my reseal kit those where green.

jdschwass

When you installed the reseal kit, were the old ones also green? Or were they black?

Sheep Herder

Old ones where black, but no know service history on truck or pump.