Fuel pump - F-Series & SuperDuty Diesel Forums

arrowstrap · 09-30-2011, 12:06 AM

i have a diesel leak and i cant find its source. i hear the pump leaks before quitting. i have had intermittent long starts and idle drops. i found a few pumps and was wondering if anyone has anything bad to say about them...

Airtex Mechanical Fuel Pump $69

Alliant Power Mechanical Fuel Transfer Pump $147

i will be replacing the rubber fuel line sections as weel. they look pretty worn.

bbressler · 09-30-2011, 09:38 AM

I've replaced mine about 4 or 5 times -- I've used the Airtex (may be why I've replaced it so many times!)

When the pump itself leaks, there's a weep hole on the passenger side right above where it enters the block. You'll want to clean the area well and maybe you can see it leaking.

I also had a fuel leak that I've not heard of before, mine was where the lines go into the back of each head. The line from the fuel pump has a rubber bushing on it that allows some give in the line and that was the source of my latest leak. I ended up removing the stock mechanical pump (went with electric pump from a SD) and replacing all the lines. I used brake lines to replace the lines in the back of the heads and that fixed that deal.

arrowstrap · 10-02-2011, 12:14 PM

i dont see any weep holes on the pump. no diesel on the pump either. i can see a drip of diesel on the hose spout elbow on the bottom of the fuel bowl where the rubber hose connects... but its not on the rubber, just the fuel bowl elbow.

i do not see any fuel drips while the truck is running. its could be burning off. it the truck is off it will drip all day. i dont know where it is from unless the system is still pressurized and it is escaping... from somewhere. if i dont run the truck a few days it takes a few more engine turns to start up.

also, if the oil is overfilled by 3 quarts, can it find its way into the fuel system? my filter was coated with a greasy oil but it is much thicker than when i had leaky injector o-rings.

BJS · 10-03-2011, 07:32 AM

take a look at this image you can see the weep hole right at the bottom

bbressler · 10-03-2011, 10:45 AM

Extra oil should not go to fuel system -- how long ago did you replace the injector o-rings?

The most common fuel leak that MIGHT end up showing towards the bottom of the bowl would be the orings that seal up the drain. I can imagine if those are leaking (just a little) that it might run down the housing and end up at that elbow.. The housing itself could be cracked -- the fuel you're seeing is probably just the contents of the fuel bowl (that's why it seems to leak all day, lots of fuel in there..)

How many miles are on your truck?

arrowstrap · 10-04-2011, 08:53 PM

BJS, thanks for the photo... now i know what to look for.

bbressler, replaced the injectors and o-rings about 6 months ago. suppose it could be my injector cups??? before i replaced injectors the filter would collect light grey oil, this time it was dark and very thick, greasy.

i will look into the fuel bowl and pump more when i get a chance. hopefully i will see something more directional.

banana · 10-06-2011, 06:42 PM

watch out for the fuel bowl failing all together. mine actually corroded all the way through and i had to replace it.

09-30-2011, 12:06 AM	#1
arrowstrap BioMechanic Join Date: Jun 2006 Location: wa Posts: 201 Thanks: 0 Thanked 2 Times in 2 Posts	Fuel pump i have a diesel leak and i cant find its source. i hear the pump leaks before quitting. i have had intermittent long starts and idle drops. i found a few pumps and was wondering if anyone has anything bad to say about them... Airtex Mechanical Fuel Pump $69 Alliant Power Mechanical Fuel Transfer Pump $147 i will be replacing the rubber fuel line sections as weel. they look pretty worn. __________________ 1996 F350 7.3L CC LB 4x4 K&N, 3 1/2" down pipe, GP kill switch, HD torque converter, baby swamps, TS chip, 203* stat, 5" lift

09-30-2011, 09:38 AM	#2
bbressler SDD Member Join Date: Nov 2006 Location: Happy, TX Posts: 391 Thanks: 2 Thanked 10 Times in 10 Posts View Photos By: bbressler	I've replaced mine about 4 or 5 times -- I've used the Airtex (may be why I've replaced it so many times!) When the pump itself leaks, there's a weep hole on the passenger side right above where it enters the block. You'll want to clean the area well and maybe you can see it leaking. I also had a fuel leak that I've not heard of before, mine was where the lines go into the back of each head. The line from the fuel pump has a rubber bushing on it that allows some give in the line and that was the source of my latest leak. I ended up removing the stock mechanical pump (went with electric pump from a SD) and replacing all the lines. I used brake lines to replace the lines in the back of the heads and that fixed that deal. __________________ Ben 1994 F-350 White Crew Cab 2wd - 300K miles & counting... DIY Air Intake, Adjustable 220-10K Mod, Shimmed FRP, custom laptop mount, EBPV Exhaust Brake, CARR hoop steps, EOT resistor mod Plantdrive two-tank WVO kit with hotfox, 26 plate FPHE, Vegmax filters, vegtherm 91 Gallon RDS Tank/Toolbox combo

10-02-2011, 12:14 PM	#3
arrowstrap BioMechanic Join Date: Jun 2006 Location: wa Posts: 201 Thanks: 0 Thanked 2 Times in 2 Posts	i dont see any weep holes on the pump. no diesel on the pump either. i can see a drip of diesel on the hose spout elbow on the bottom of the fuel bowl where the rubber hose connects... but its not on the rubber, just the fuel bowl elbow. i do not see any fuel drips while the truck is running. its could be burning off. it the truck is off it will drip all day. i dont know where it is from unless the system is still pressurized and it is escaping... from somewhere. if i dont run the truck a few days it takes a few more engine turns to start up. also, if the oil is overfilled by 3 quarts, can it find its way into the fuel system? my filter was coated with a greasy oil but it is much thicker than when i had leaky injector o-rings. __________________ 1996 F350 7.3L CC LB 4x4 K&N, 3 1/2" down pipe, GP kill switch, HD torque converter, baby swamps, TS chip, 203* stat, 5" lift

10-03-2011, 07:32 AM	#4
BJS SDD Senior Member Join Date: Apr 2005 Location: Jacksonville, FL Posts: 1,498 Thanks: 4 Thanked 141 Times in 134 Posts	take a look at this image you can see the weep hole right at the bottom __________________ Brandon 95 F350 Centurion Conversion Bronco (Crew Cab SRW) 4X4 4.10, Isspro Performax Boost, Pyro, & trans temp on the A-pillar, BDP Stage 1 injectors, Open air intake, Dpp Downpipe, Self built E4OD with parts from Racer-X, Tony Wildman Chip, Early '99 Intercooler.

10-03-2011, 10:45 AM	#5
bbressler SDD Member Join Date: Nov 2006 Location: Happy, TX Posts: 391 Thanks: 2 Thanked 10 Times in 10 Posts View Photos By: bbressler	Extra oil should not go to fuel system -- how long ago did you replace the injector o-rings? The most common fuel leak that MIGHT end up showing towards the bottom of the bowl would be the orings that seal up the drain. I can imagine if those are leaking (just a little) that it might run down the housing and end up at that elbow.. The housing itself could be cracked -- the fuel you're seeing is probably just the contents of the fuel bowl (that's why it seems to leak all day, lots of fuel in there..) How many miles are on your truck? __________________ Ben 1994 F-350 White Crew Cab 2wd - 300K miles & counting... DIY Air Intake, Adjustable 220-10K Mod, Shimmed FRP, custom laptop mount, EBPV Exhaust Brake, CARR hoop steps, EOT resistor mod Plantdrive two-tank WVO kit with hotfox, 26 plate FPHE, Vegmax filters, vegtherm 91 Gallon RDS Tank/Toolbox combo

10-04-2011, 08:53 PM	#6
arrowstrap BioMechanic Join Date: Jun 2006 Location: wa Posts: 201 Thanks: 0 Thanked 2 Times in 2 Posts	BJS, thanks for the photo... now i know what to look for. bbressler, replaced the injectors and o-rings about 6 months ago. suppose it could be my injector cups??? before i replaced injectors the filter would collect light grey oil, this time it was dark and very thick, greasy. i will look into the fuel bowl and pump more when i get a chance. hopefully i will see something more directional. __________________ 1996 F350 7.3L CC LB 4x4 K&N, 3 1/2" down pipe, GP kill switch, HD torque converter, baby swamps, TS chip, 203* stat, 5" lift

10-06-2011, 06:42 PM	#7
banana SDD Member Join Date: Oct 2005 Location: new port richey, fl. us Posts: 113 Thanks: 4 Thanked 0 Times in 0 Posts View Photos By: banana	watch out for the fuel bowl failing all together. mine actually corroded all the way through and i had to replace it. __________________ 1997 f250 7.3 powerstroke. 6inch skyjacker lift, 37x12.50 bfg km2 MTs.

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