Fuel Pump Maintenance Tips
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Originally Posted By: HangFire
Originally Posted By: PeterPolyol
That's a good question. I was always under the impression that everything inside the pump is saturated in fuel; brushes, bearings, armiture etc. Had to actually google search for something to back it up.
Brushes cannot be in fuel, because they spark.
Of the millions and millions of vehicles on the road with in-tank electric fuel pumps, don't you think that eventually fuel would get to the brushes and cause an explosion, some how, some way?
There isn't the proper fuel/oxygen ratio in a gas tank to support combustion or explosion, unlike what the Hollywood movie-makers would have you believe.
Originally Posted By: PeterPolyol
That's a good question. I was always under the impression that everything inside the pump is saturated in fuel; brushes, bearings, armiture etc. Had to actually google search for something to back it up.
Brushes cannot be in fuel, because they spark.
Of the millions and millions of vehicles on the road with in-tank electric fuel pumps, don't you think that eventually fuel would get to the brushes and cause an explosion, some how, some way?
There isn't the proper fuel/oxygen ratio in a gas tank to support combustion or explosion, unlike what the Hollywood movie-makers would have you believe.
Originally Posted By: PeterPolyol
That's a good question. I was always under the impression that everything inside the pump is saturated in fuel; brushes, bearings, armiture etc. Had to actually google search for something to back it up.
here's the standard Denso style which I'm familiar with.
Side-note: full internal saturation effectively renders tank level inconsequential to pump life and cooling.
Yeah, I guess it really doesn't matter as I've never had a Denso pump fail even after all they years and miles on my cars.
That's a good question. I was always under the impression that everything inside the pump is saturated in fuel; brushes, bearings, armiture etc. Had to actually google search for something to back it up.
here's the standard Denso style which I'm familiar with.
Side-note: full internal saturation effectively renders tank level inconsequential to pump life and cooling.
Yeah, I guess it really doesn't matter as I've never had a Denso pump fail even after all they years and miles on my cars.
Originally Posted By: kschachn
Yeah, I guess it really doesn't matter as I've never had a Denso pump fail even after all they years and miles on my cars.
Absolutely, me either. Probably the best pumps in the industry. Denso as an OEM supplier has the best QC/QA in the industry IMO.
Yeah, I guess it really doesn't matter as I've never had a Denso pump fail even after all they years and miles on my cars.
Absolutely, me either. Probably the best pumps in the industry. Denso as an OEM supplier has the best QC/QA in the industry IMO.
I guess I've just been lucky...
1993 Ford Ranger, 5.0 liter - 284,000 miles on the original (4 cylinder) fuel pump.
1996 Mustang GT 4.6 - 176,000 miles on original fuel pump
2008 F150 146,000 original fuel pump
1997 Mustang Cobra Convertible DOHC 4.6 - only 112,000 & probably most likely to have fuel pump die since I hardly ever drive it.
1993 Ford Ranger, 5.0 liter - 284,000 miles on the original (4 cylinder) fuel pump.
1996 Mustang GT 4.6 - 176,000 miles on original fuel pump
2008 F150 146,000 original fuel pump
1997 Mustang Cobra Convertible DOHC 4.6 - only 112,000 & probably most likely to have fuel pump die since I hardly ever drive it.
External cooling does matter to a fuel pump. That's why marin engines, although using traditional electric fuel pump designs, cool the pumps with raw water. When the raw water circuit is clogged, the pumps begin to suffer quickly.
however, many vehicles have their fuel pump living in a basket that is kept full of fuel by design. In my Rams, the basket is kept full of fuel by the return fuel coming back from the engine. I've changed pumps in these trucks where the tank was nearly empty. Basket was full to the brim.
however, many vehicles have their fuel pump living in a basket that is kept full of fuel by design. In my Rams, the basket is kept full of fuel by the return fuel coming back from the engine. I've changed pumps in these trucks where the tank was nearly empty. Basket was full to the brim.
Originally Posted By: MRtv
Actually one of the main reasons I use MMO in my fuel. My fuel pump is in the fuel tank and replacing it will be a problem if I ever have to. So I use MMO to lubricate the pump and hopefully, I say hopefully, never have to worry about it.
Originally Posted By: PeterPolyol
TWC-3 at ridiculously dilute ratios.
How much of MMO or TWC-3 per 10 gallon tank?
Actually one of the main reasons I use MMO in my fuel. My fuel pump is in the fuel tank and replacing it will be a problem if I ever have to. So I use MMO to lubricate the pump and hopefully, I say hopefully, never have to worry about it.
Originally Posted By: PeterPolyol
TWC-3 at ridiculously dilute ratios.
How much of MMO or TWC-3 per 10 gallon tank?
Originally Posted By: kschachn
As others have mentioned I also don't think the "keeping the tank above 1/4" has anything to do with it. My custom is to run right down to empty virtually every time, and my fuel pumps are fine.
Agreed. The pump is cooled by fuel running through the inside of the pump, not sitting on the outside. So don't let air run through it for an extended period, which is not going to happen anyways because the engine will die.
If they really needed external cooling, then they would add additional cooling to direct injection high pressure pumps. Those create far greater heat as they are putting out pressure around 6000 PSI, and are usually sitting on top of the engine, which gets much hotter than sitting in the tank. Although, they are mechanical pumps and not electrical.
Only thing you can do is to run fuel without ethanol.
As others have mentioned I also don't think the "keeping the tank above 1/4" has anything to do with it. My custom is to run right down to empty virtually every time, and my fuel pumps are fine.
Agreed. The pump is cooled by fuel running through the inside of the pump, not sitting on the outside. So don't let air run through it for an extended period, which is not going to happen anyways because the engine will die.
If they really needed external cooling, then they would add additional cooling to direct injection high pressure pumps. Those create far greater heat as they are putting out pressure around 6000 PSI, and are usually sitting on top of the engine, which gets much hotter than sitting in the tank. Although, they are mechanical pumps and not electrical.
Only thing you can do is to run fuel without ethanol.
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Originally Posted By: mightymousetech
Only thing you can do is to run fuel without ethanol.
I doubt that makes much difference either, we live in an EPA non-attainment area and RFG has been mandated here as far back as I can remember. All my vehicles have run on it since new as has all my OPE, the only E0 available is 15 miles away. I just don't see the issues some people seem to have with EtOH.
Only thing you can do is to run fuel without ethanol.
I doubt that makes much difference either, we live in an EPA non-attainment area and RFG has been mandated here as far back as I can remember. All my vehicles have run on it since new as has all my OPE, the only E0 available is 15 miles away. I just don't see the issues some people seem to have with EtOH.
Originally Posted By: HangFire
Originally Posted By: PeterPolyol
That's a good question. I was always under the impression that everything inside the pump is saturated in fuel; brushes, bearings, armiture etc. Had to actually google search for something to back it up.
Brushes cannot be in fuel, because they spark.
I've taken apart a couple of fuel pumps. One was an inline bullet-style, external to the tank. Another was internal to the tank. They were both completely immersed in and filled with fuel. The entire inline pump had fuel flowing through it-- the tank style just bathed in it. Both had brushes. One failed from spring collapse holding one of the brushes to the commutator. The other ... I didn't take apart.
Originally Posted By: PeterPolyol
That's a good question. I was always under the impression that everything inside the pump is saturated in fuel; brushes, bearings, armiture etc. Had to actually google search for something to back it up.
Brushes cannot be in fuel, because they spark.
I've taken apart a couple of fuel pumps. One was an inline bullet-style, external to the tank. Another was internal to the tank. They were both completely immersed in and filled with fuel. The entire inline pump had fuel flowing through it-- the tank style just bathed in it. Both had brushes. One failed from spring collapse holding one of the brushes to the commutator. The other ... I didn't take apart.
Originally Posted By: MoneyJohn
Originally Posted By: MRtv
Actually one of the main reasons I use MMO in my fuel. My fuel pump is in the fuel tank and replacing it will be a problem if I ever have to. So I use MMO to lubricate the pump and hopefully, I say hopefully, never have to worry about it.
Originally Posted By: PeterPolyol
TWC-3 at ridiculously dilute ratios.
How much of MMO or TWC-3 per 10 gallon tank?
I put in 3 to 4 oz. per ten gallons of fuel of the MMO.
Originally Posted By: MRtv
Actually one of the main reasons I use MMO in my fuel. My fuel pump is in the fuel tank and replacing it will be a problem if I ever have to. So I use MMO to lubricate the pump and hopefully, I say hopefully, never have to worry about it.
Originally Posted By: PeterPolyol
TWC-3 at ridiculously dilute ratios.
How much of MMO or TWC-3 per 10 gallon tank?
I put in 3 to 4 oz. per ten gallons of fuel of the MMO.
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I don't do anything in particular and the pump has lasted over 200K in my FFV Ranger with lots of E85 usage. I have run Techron through it occasionally, but that's it. It has been run low enough for the warning light to come on multiple times, but usually gets refilled when it gets to a 1/4 tank on the gauge, and has never run out of fuel in its life. The gauge has been intermittent for years now, only working when temps are above about 70*F, so it hasn't been run low in a while. The fuel filter has been replaced maybe 3 times since new.
I think the main thing that keeps a fuel pump lasting forever or failing early is the DNA of the fuel pump. In other words, the OEM manufacturer.
I've got a '96 Jeep Cherokee that's closing in on 300K miles that still has the original pump. I've had four Aerostar vans, each one making it over 250K miles and I never changed a fuel pump in any of them.
On the other hand, I had an '88 Cougar purchased brand new and I had to replace the fuel pump in that car twice, although this car made it to 300K miles.
I've got a '96 Jeep Cherokee that's closing in on 300K miles that still has the original pump. I've had four Aerostar vans, each one making it over 250K miles and I never changed a fuel pump in any of them.
On the other hand, I had an '88 Cougar purchased brand new and I had to replace the fuel pump in that car twice, although this car made it to 300K miles.
Originally Posted By: Kibitoshin
IMO fuel pump life is at the mercy of the brushes in the motor. With a lot of cordless power tools going brushless why haven't fuel pumps gone brushless yet?
Price.
In my 20 years of being a tech, I have only ever seen one failed fuel pump.
IMO fuel pump life is at the mercy of the brushes in the motor. With a lot of cordless power tools going brushless why haven't fuel pumps gone brushless yet?
Price.
In my 20 years of being a tech, I have only ever seen one failed fuel pump.
Originally Posted By: kschachn
Originally Posted By: mightymousetech
Only thing you can do is to run fuel without ethanol.
I doubt that makes much difference either, we live in an EPA non-attainment area and RFG has been mandated here as far back as I can remember. All my vehicles have run on it since new as has all my OPE, the only E0 available is 15 miles away. I just don't see the issues some people seem to have with EtOH.
x's 2
My wife and I cumulatively have driven well over 700k miles in our vehicles- primarily on ethanol blended fuel- and surprise!, I think I've only put 1 or 2 pumps in.
This ethanol thing is like the "Pennzoil causes sludge" myth... it just doesn't go away. Next thing you know, it'll be the source of miscarriages, divorce, and lowered IQ.
More in the realm of reality, pumps can and do wear out. Brushes are the most common. Another huge contributor (here's lookin at you GM) is faults in wiring. A poor power or ground (mid 90's GM trucks had a braided strap that would rot away, which broke the ground path to the pump) will increase amp draw and eventually burn the pump up.
Originally Posted By: mightymousetech
Only thing you can do is to run fuel without ethanol.
I doubt that makes much difference either, we live in an EPA non-attainment area and RFG has been mandated here as far back as I can remember. All my vehicles have run on it since new as has all my OPE, the only E0 available is 15 miles away. I just don't see the issues some people seem to have with EtOH.
x's 2
My wife and I cumulatively have driven well over 700k miles in our vehicles- primarily on ethanol blended fuel- and surprise!, I think I've only put 1 or 2 pumps in.
This ethanol thing is like the "Pennzoil causes sludge" myth... it just doesn't go away. Next thing you know, it'll be the source of miscarriages, divorce, and lowered IQ.
More in the realm of reality, pumps can and do wear out. Brushes are the most common. Another huge contributor (here's lookin at you GM) is faults in wiring. A poor power or ground (mid 90's GM trucks had a braided strap that would rot away, which broke the ground path to the pump) will increase amp draw and eventually burn the pump up.
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