Fuel line question - filter to IP

[JTodd]

I am chasing a fairly serious fuel leak. It is coming from the rear of the engine, and so far I have change the fuel filter lower o-ring and replaced the spring clips with screw type hose clamps. The leak is still there. And by leak, I mean that it will pour out the entire contents of the fuel filter bowl. There is no apparent degradation in engine performance. It starts and runs without any fuel starvation issues. The odd thing is it appears to leak worst when the truck is not running

My next step is to replace the rubber fuel lines on both sides of the fuel filter bowl. The big question is that to replace the two lines between the filter and the IP, do I need to remove the intake manifold?

[handcannon]

It is possible to replace them without pulling the lower intake. Connect the old and new together with wire or a piece of rod and clamps and carefully pull it through.

Or, do what I did. I got two pieces of metric threaded rod (I think I remember something about 6" long) and remount the FFM up higher than stock. This allowed me to easily route the fuel lines along side the lower manifold. This gets them out where they are in a bit cooler environment. You can also replace the water drainline easier this way and eliminate that as a possible leak.

Don

[AllThumbs]

I had a problem much like that when I changed my fuel filter. The filter simply was not seating. Mine did not leak when the truck was not running though. Fuel would pour out when the lift pump was running.:eek:

[JTodd]

It is possible to replace them without pulling the lower intake. Connect the old and new together with wire or a piece of rod and clamps and carefully pull it through.

Or, do what I did. I got two pieces of metric threaded rod (I think I remember something about 6" long) and remount the FFM up higher than stock. This allowed me to easily route the fuel lines along side the lower manifold. This gets them out where they are in a bit cooler environment. You can also replace the water drainline easier this way and eliminate that as a possible leak.

Don

While working on them, I wiggled them to see where they come out up front, but did not see the other end of either. Do they go straight forward, or connect toward the side of the IP?


I had a problem much like that when I changed my fuel filter. The filter simply was not seating. Mine did not leak when the truck was not running though. Fuel would pour out when the lift pump was running.

Mine actually seems to leak worse when not running. I have also tried two different filters, but still a huge leak. I have not captured the run-off, but I would say it is at least the entire volume of the filter bowl.

[handcannon]

You have a 96, is it a dual thermostat? I don't remember if it was 96 or 97 when the change to dual took place. I am going to assume it is. The thermo housing protrudes rearward and covers a lot of the IP.

Stand at the front of the vehicle and look under the thermostat housing. You'll see a round canister about 1.5" diameter and 3" tall (the fuel shut-off soliniod) on top of the IP. The fuel line will be directly behind that. The fuel line comes up from underneath the manifold, bends forward, and connects to the IP.

The second line is the water drain. It comes forward from the FFM and out to the passenger side of the IP. It culminates in a small t valve that is bolted to the passenger side of the thermo housing. The t valve has a line that continues on down the front of the motor to drain away liquids when the drain valve is opened.

The line between the t valve and the FFM is pressurized the same as the fuel line is. With these two lines under the manifold it is very hard to see leaks if they develop a leak.

Don