Carter fuel pump leaking

[Dragon Slayer]

I am just trying to be a little more helpful with a little more detail. The first link was to the 6 bolt pump. So you do not need to get your panties in a bunch. Throwing out numbers or info without specific is not always helpful.
Mancini is kind of unique in that they assigned the same part number to two different style fuel pumps, and the 6 bolt was a Chevy/Ford type with a Mopar lever. Pictures show the difference.
Just trying to help someone avoid a mistake in an order.

By the way, Mancini apparently just started to re-carry the 8 bolt M6903. As most OEM type guys would not want the 6 bolt on the car. Of course they don't want the new bulge style either, but that is the only way new pumps come now a days.

 

[moparnation74]

No one said you were not helpful.....lol. That's just what you ASSumed......

You made good points as others did....

It's a collaboration.....and Mancini provided adequate information to deduce what's needed.....or what's not....

 

[SlinktRR]

https://www.summitracing.com/parts/qft-30-440qft

I stopped using the carter m6903 and edelbrock mechanical pumps after diaphragm failures. The edelbrock put gas into the crankcase. I have had the quick fuel 110 gph pump for about 5 years now on two engines and it performs well without a problem.

 

[Dragon Slayer]

That is interesting, I have not taken a new one apart yet, but I have taken originals and rebuilt them. The ones I have done go on car's that want to remain OEM. I am going to put a cheater electric pump on my hemi car though to prime the carbs before starting. But only for starting.

By design it really should not put fuel in the crankcase. You have 2 sealed chambers and an upper seal and vent hole. So unless your using a cheater pump to pressurize the mechanical the fuel should not be able to get into the crankcase without multiple failures, and coming out the weep hole. Unless maybe a car with a fuel tank in the trunk and above the fuel pump. Looking at the diaphragm it has the upper seal that is held against the upper housing machined surface. This prevents oil from getting into the pump and gas out. Marine pumps do have the brass vent on that hump on newer styles; but they are worried about raw gas in the bilge and a bilge explosion. Once the diaphragm splits, you lose your pump. Have not opened an edelbrock pump.

 

[Sixpactogo]

Hi all, just noticed my fuel pump on the 440 is leaking out of the 2 small holes on the main body. It's squirting out both sides when the engine is running. What would cause this? cheers in advance. Matt

I just wanted to mention that those two holes are there for a couple of good reasons. One, is to tell you that the diaphragm has failed and the other (more important) is to divert the leaked fuel out onto the ground instead of into the crankcase.

 

[SlinktRR]

That is interesting, I have not taken a new one apart yet, but I have taken originals and rebuilt them. The ones I have done go on car's that want to remain OEM. I am going to put a cheater electric pump on my hemi car though to prime the carbs before starting. But only for starting.

By design it really should not put fuel in the crankcase. You have 2 sealed chambers and an upper seal and vent hole. So unless your using a cheater pump to pressurize the mechanical the fuel should not be able to get into the crankcase without multiple failures, and coming out the weep hole. Unless maybe a car with a fuel tank in the trunk and above the fuel pump. Looking at the diaphragm it has the upper seal that is held against the upper housing machined surface. This prevents oil from getting into the pump and gas out. Marine pumps do have the brass vent on that hump on newer styles; but they are worried about raw gas in the bilge and a bilge explosion. Once the diaphragm splits, you lose your pump. Have not opened an edelbrock pump.

View attachment 605891

That is a really good point. One thing about anecdotal evidence.. key details can be overlooked. My car is also set up for a pusher electric too, in this case a holley red. I rarely use it because it's noisy as hell but I have used it to prime on occasion. When the edelbrock failed, this could have been part of the gas-in-crankcase issue. Other possibilities for general failure can be age of the diaphragms, manufacturing changes of the pump seals over time to address gasoline composition (ethanol), how long the pump sat on shelf before it was installed, stuff like that.

So yeah I should clarify my QFT pump endorsement...I have used the same pump on two BBM engines, rarely engage the pusher electric, and I have not had any probs yet. That doesnt mean the Carter and Edelbrocks are junk, but I have had failures on both. Doesnt mean someone should run out and change a carterbrock pump if they have one running fine. That said, I have been happy with the quickfuel and it's a solid option.

To that end, after having the pusher setup I would also suggest not using the pusher if you can avoid it. If your fuel line lost prime, might be better to just run starter fluid in the carb and get the motor to fire enough to engage the mech pump and fill the bowls. I use the electric as a backup in case the mech pump fails or the fuel pump pushrod gets ground down. In those cases, I would re-plumb for the electric to go right into the regulator and bypass the mech pump.

 

[crossram 426]

I just wanted to mention that those two holes are there for a couple of good reasons. One, is to tell you that the diaphragm has failed and the other (more important) is to divert the leaked fuel out onto the ground instead of into the crankcase.

Thanks, that was my thought too!