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Fuel Filter Manager leak

SnowDrift

SnowDrift

Ultra Conservative. ULTRA!
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In some reading, it looks like several things can leak on the FFM. I suspect the o-ring on the bottom since it's pretty stiff, although it's not cracked. Is there a good way to test this before putting it back in the truck, after I install new O-rings? I guess just cap the outlet ports and put air pressure into the manager?

The pinhole in the heater that people mention - is this usually easily visible?

The wires leaking - either for the water indicator or the heater wires - is there a good way to check any of these?
 
Thanks. I'll see if I can locate the O-rings. Looks like the big one is a #134, measuring 1-7/8" ID x 2-1/16" OD x 3/32 on the roundth. I'm not sure of the small one for the water indicator. Anyone have this?
 
The hole was visible on mine. Replace all seals. Thats another item I tried to cheat and ended up taking out again.
 
From the dealership, it says it is 25/64 ID x 45/64 OD - thickness should be 5/32 if this is the case. Seems a little fat, but I'll see once I get it in my hands.
 
FYI mine are made of Viton & OK to use with the new BioD fuels, $16 shipped. GM will be Buna rubber.
 
Bleeder, If you can wait, Viton is the way to go IMO. I keep my old steel forever, so I went that way.
 
O-rings didn't do it. Leaking profusely from wires on water indicator, from what I can see. Only leaks after cranking for a while, though, not when I pressurize the system manually with the lift pump. Does this make sense?
 
SnowDrift said:
O-rings didn't do it. Leaking profusely from wires on water indicator, from what I can see. Only leaks after cranking for a while, though, not when I pressurize the system manually with the lift pump. Does this make sense?
Click to expand...


That seems to be normal. On the Suburbans I thought i would be able to tell where the leak was by hot wiring the lift pump, but I could never tell anything by doing that. They would have a huge leak when running.
 
I figured maybe there is something in there around the wires that "pops" out of the way when the pressure increases and then allows the fuel to flow. I talked with the guy I bought the truck from the other day and he said the owner before him mentioned a fuel problem of some sort - he may have even said a fuel leak.

New part is scheduled to be at my door tomorrow.
 
...or, maybe I just didn't see the fuel flowing in from the disconnected line. Boy, I feel like a dope. Anyone need a new FFM?
 
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