Engine/Transmission (1994 - 1998) Fire at Fuel Strainer/Heater

[-Alex-]

I had a small fire start on the thermostst on the fuel heater when I started my truck the other day. After blowing fire out (Glad it wasn't gasoline) I noticed there was a lot of fuel leakage in the area of the fuel strainer assembly, the whole wire harness for the heater was soaked. I'm not sure which came first the leak or the fire, I'm assuming the leak. Haveing since read a couple of other posts on this problem I thought it was leaking through the thermostat attachment, but that is completely isolated from fuel. The heater itself, which is sandwiched between the strainer bowl and the housing, was pretty loose.



So, should screwing the heater back on tight fix my leak? I plan on leaving the heater unpluged as I don't see that much cold weather. Anybody else seen this problem? Thanks,



-Alex-

 

[bmoeller]

Don't know about fire, but the fuel leak there have been posted before.



There are some gaskets that can be replaced.



http://www.dodgeram.org/tech/dsl/Facts/96specs.html#parts



Some of these part numbers are still good. Others have been superseded.

 

[Andy Redmond]

The orings probably got hot and thus your leak.



You have a casting, then a oring, the heater, the "flanged" nut that holds the heater to the casting, then the oring for the bowl. Inside the bowl is the strainer and nut.



You might also get the compression washer (rubber) thats inside the metal tube that connects to the lift pump.



The 90 deg. L rubber hose could be changed while your right there to prevent probs later.



Lets hope it didn't warm up the check valves/orings in the lift pump too!







Good luck

Andy

 

[Joe G.]

Alex,



Since you live in a warm climate you can take the fuel heater out and leave it out. Remove the prefilter bowl. There is a big shiny screw that holds the heater on. Remove it with an allen wrench. Remove the fuel heater. The pre-filter will bolt right up where the heater was. The shiny screw is just an adapter.



Your leak is probably at the electrical connector for the heater. When it gets hot it melts an electrical joint inside just behind the electrical connector. That causes the connector to leak. Tightening up the hearter and pre-filter screws has no affect on that leak.

 

[krs]

"Remove the fuel heater. The pre-filter will bolt right up where the heater was. The shiny screw is just an adapter".



Good tip - thanks Joe.

 

[-Alex-]

Thanks to All. After digging up and reading some of the older posts on this subject there are some theories involving overheating of the fuel heater and thermostat due to lack of fuel due to air being sucked in while sitting. I've only experienced this once a few months ago after being parked nose up 30* for a couple of days. Probably time to R/R the return hoses again, and I'm going to throw a new lift pump at it also. Fuel pump pressure has dropped to the lower limits (18 PSI at idle, was 22 at last check).



-Alex-

 

[Joe G.]

Here is what the fuel heater / pre-filter assembly looks like. The heater part may be removed along with the screw for it. The lower part (pre-filter) will bolt right up. The gaskets are the same for both parts. If you are careful the gasket may be used over.

#ad

 

[JGheen]

Joe G. ,



Can one just disconnect the power to the fuel heater to prevent that fire from happening?? It gets somewhat cold here from time to time and I want to be able to still use my fuel heater when needed. I also pulled out my relay to the grid heaters to prevent a fire as well since the summer months are comin' around and it is gonna be hotter than blazes down here in So. Cal. Hey, what about just removing the relay for the fuel heater, could I do that instead of disconnecting the wire at the heater istelf??

 

[Joe G.]

Yeah, you can do any of that. I don't know how cold it has to get before the fuel heater is important. I suspect that it doesn't ever get that cold in So Cal. I took mine out because it was leaking. Not to bad but just a drip ever couple of seconds. I found that the drip was coming from the electrical connector to the fuel heater. (long story how I found that) I took the heater out. It looked ok, but it leaked around one of the pins in the connector. I drilled the aluminum rivits out so I could take the heater apart. The inside end of the leaking pin was burnt off where it connected to the heating element. I tried to find just the heater element, but could only buy the whole fuel heater/pre filter assembly. Then I noticed that the threads looked the same on the pre filter as the screw that held the heater. So I put it together without the heater. No leaks. Works fine. It's been that way for about six months. No problems. It doesn't get cold over here on the coast. Maybe down to 25 sometimes. I don't go places that are cold if I can help it. If I can find a source for the heater element I will replace it. If not, I won't.

 

[JGheen]

So, according to your pics posted above, can you just take out the entire fuel heater assembly and put it back together or do you just remove the heater element inside it and retain the assembly?? I think that is the element in the middle of the assembly correct??

 

[Joe G.]

You don't need to take the assembly off the engine. All you need is a 17 mm socket and an allen wrench. I forget what size. Unplug the electrical connector. Take the pre-filter off the bottom with the socket. Be careful or you will get a diesel bath. Remove the big screw with the allen wrench. That will release the heater element. Remove it. Then just screw the bottom part with the pre-filter back on. If you are careful with the gasket (use the best one) you are done. It should take less than five minutes.

 

[-Alex-]

OK. It's all back together, sans heater, just as Joe described. No leaks. Will contemplate putting heater in later. New fuel pump has fuel pressure back up to 23psi, and managed to get new starter contacts in while I had the starter out.

All is good again, I think I go and wash the beast!

 

[JGheen]

Sounds easy enough. And as for the electrical connector, just leave it unplugged?? Also, to avoid a diesel bath, can you loosen the 17mm nut a little before complete removal and let it drain into a bucket??

And the allen screw that holds the element inside, do you need to replace that or can you just leave it out as well??

BTW, where did you get that diagram of the pre-filter? Is it out of some Cummins service manual or something??

 

[Joe G.]

My electical connector is just hanging there unplugged. No problems. It's not long enough to get into trouble. There is a short harness that goes to the heater and the temp sensor. Remove that with the heater. The connector the harness connects to is on a cable. I forgot about that. My temp sensor burnt up so I had the harness off trying to find another. No luck at that.



When I clean my pre-filter I use a long extension, a u-joint, and the 17mm socket. That gets me out of the way so the diesel doesn't get on me. I use a small drain pan under it.



There is no allen screw. The big screw has a hex hole in the middle. I just checked the screw. The allen wrench needed is 8mm.



The diagram is out of my Dodge service manual. If you don't have one you REALLY should.

 

[-Alex-]

LMAO at myself, I've got the Chrysler manual - had forgotten to dig it out.

 

[JGheen]

Originally posted by Joe G.





There is no allen screw. The big screw has a hex hole in the middle. I just checked the screw. The allen wrench needed is 8mm.



The diagram is out of my Dodge service manual. If you don't have one you REALLY should.

Did you say you just "chucked" the screw and didn't even replace it since it just holds the element in?



Where did you get your service manual?? Is it a Chiltons manual?

 

[Joe G.]

I still have the parts. One of these days I may get a new heater. Probably not.



My service manual is the Dodge service manual. You buy it from Chrysler. The competing manuals would probably work ok in an out house.

 

[-Alex-]

Ordered mine direct from Chrysler, the order info is in the back of my owners manual:

Dyment Distribution Services

P. O. Box 360450

Strongsville, OH 44136

800-890-4038



$90. plus S&H



Worth every penny (when I remember to look in it)

 

[JGheen]

$90!!:--) That's insane!! Is it a pretty thick book with everything from the engine to the axles??

 

[-Alex-]

Phone book size and comes with a service and bodywork supplements. Way more info then I hope to ever use, handy when you need it.