In-the-tank fuel pumps cause death and destruction

Right Matt, I did not mean cavitation. I meant take the prop out of the
water, rev the engine all the way up (in gear) then drop the prop back in
the water........

 

Yep, he probably drives around on "E" alot

 

I don't actually... the '88 is mine... I fill it up every week, the
gauge rarely gets below 1/2 tank. the '90 is my dad's w/ 330,000
miles on it, his gas gauge doesn't work anymore and has been run out
of gas quite a few times. the '93 is my brothers, I don't know his
gas habits. the '98 is a company truck that frequently gets run down
to E before filling it up.. it's pump died at 110,000 miles. the '01
is my dad's partner's and he's babies the hell out of that truck.

-Bret

as for being hard on them... I expect the 3/4 tons to do 3/4 ton work,
plain and simple.

 

Or buys cheap gas full of water, dirt, etc.


Matt

 

A lot of people are convinced it costs more to keep the top 1/4 of the
tank filled than the bottom 1/4.

 

I've got an '87 F150 with duel tanks and I reguarly run the rear tank dry
before switching to the front tank. Its got 133K miles on it now. I bought
it with 85K miles on it. I'm sure they're both origional pumps.

I get at least 250 on one tank and start thinking of fiiling it up with 200
miles on the second tank. Usually fillup with 33 gallons out of 38 gallons
possible.


| On Sat, 06 Nov 2004 17:31:18 GMT, "Scott M" <>
| wrote:
|
| >
| >| >> Bret Chase wrote:
| >>> On Fri, 05 Nov 2004 18:01:27 -0500, Matt Whiting
| >>>
| >>>
| >>>>:|Scott M wrote:
| >>>>:|
| >>>>| >>>>:|> :|>>Scott M wrote:
| >>>>:|>>
| >>>>:|>>
| >>>>:|>>>| >>>>:|>>>
| >>>>:|>>>
| >>>>:|>>>> wrote:
| >>>>:|>>>>
| >>>>:|>>>>
| >>>>:|>>>>
| >>>>:|>>>>>On Tue, 02 Nov 2004 16:53:18 -0500, Matt Whiting
| >>>>:|>>>>>
| >>>>:|>>>>>
| >>>>:|>>>>>
| >>>>:|>>>>>>Alex Rodriguez wrote:
| >>>>:|>>>>
| >>>>:|>>>>>>>this also means you should keep your tank level from getting
too
| >>>>low. :|>>>>>>>Otherwise you can shorten the life of your pump.
| >>>>:|>>>>>>
| >>>>:|>>>>>>Another urban legend.
| >>>>:|>>>>>>
| >>>>:|>>>>>>Matt
| >>>>:|>>>>>
| >>>>:|>>>>>Not totally. Running the pump VERY low on fuel reduces cooling
and
| >>>>:|>>>>>lubrication and CAN hasten the pump's demise.
| >>>>:|>>>>
| >>>>:|>>>>Absolutely not on lubrication. It is impossible not to have
| >>>>gasoline in :|>>>>the pump at the bearings if the vehicle is running
off
| >>>>of fuel from the :|>>>>pump since the bearings (more accurately,
bushings
| >>>>in almost all consumer :|>>>>vehicles)are within the internal pump
volume
| >>>>(the shaft and bearings are :|>>>>surrounded by the fuel as it flows
thru
| >>>>the pump. If there's no gasoline :|>>>>at the bearings, neither is
there
| >>>>fuel getting to the engine, i.e., the :|>>>>engine will not run, and
most
| >>>>likely neither will the pump for very long :|>>>>at all (and that's
not
| >>>>"low" in fuel - that's "out of" fuel). The :|>>>>bearings running dry
or
| >>>>even slightly low is not a credible situation at :|>>>>all - not even
at
| >>>>the point that the engine cuts off due to your "running :|>>>>out of
gas"
| >>>>(at which time the pump still is full of fuel).
| >>>>:|>>>>
| >>>>:|>>>>As far as the cooling aspect, yeah - you might have that on a
| >>>>:|>>>>technicality, but you do have a steady cool volume of the fuel
| >>>>running :|>>>>thru the complete internals of the pump/motor assy. So,
| >>>>probably the :|>>>>outside surface of the pump (case and magnets,
which
| >>>>are on the inside :|>>>>surface of the case) will rise a few degrees,
but
| >>>>the insides (armature, :|>>>>brushes, bearings/bushings) would rise
| >>>>*very* little (due to the volume :|>>>>flow rate of ambient
temperature
| >>>>fluid that bathes those components. I :|>>>>doubt that those thermal
| >>>>effects are at all significant in pump life.
| >>>>:|>>>>
| >>>>:|>>>>IMO...
| >>>>:|>>>>
| >>>>:|>>>>Bill Putney
| >>>>:|>>>
| >>>>:|>>>
| >>>>:|>>>You are forgetting when the tank is very low the pump can "suck
air"
| >>>>on :|>>>corners, hills, stop and go...and that is very hard on a vane
| >>>>type pump. :|>>>It seems to kill GM pumps alot more than Fords. I just
| >>>>helped a friend :|>>>change one on his blazer-he said- I thought I was
| >>>>just out of gas, the :|>>>tank was low and I was trying to make it to
the
| >>>>next gas station. I guess :|>>>it could have been coincidence, but I
| >>>>really doubt it IMO.
| >>>>:|>>
| >>>>:|>>When you say "vane" type pump, is that roller vane, or some other
| >>>>type of :|>>vane?
| >>>>:|> :|> :|> I dont really think it would matter. Even if it was some
type
| >>>>of turbin or :|> what I think they call a slide? I believe there are
3
| >>>>problems in the case :|> I mentioned above. One is cooling by the
fuel,
| >>>>another is lubrication by the :|> fuel, and the worst one of all I
think
| >>>>is the fatigue from a gas to a liquid :|> instantly. Think of your
boat
| >>>>prop. If it catches air, the force when it :|> hits water again is
| >>>>sometimes enough to break the shear pin in the prop, :|> almost like
| >>>>hitting a log in the water at full throttle. I would say the :|>
problem
| >>>>is the higher the speed the pump turns, the more the problems with :|>
| >>>>all the above. Does that make since or do you all think I'm
caaaraaazy?
| >>>>
| >>>>:|
| >>>>:|I don't think you are crazy, I just don't think the problems you
| >>>>:|mentioned are significant. If they were, you'd see cars littering
the
| >>>>:|road side with failed fuel pumps, and that just isn't happening.
I've
| >>>>:|owned several cars over the last 20 years that had electric fuel
pumps
| >>>>:|and I've yet to have a single failure.
| >>>>:|
| >>>>:|
| >>>>:|Matt
| >>>
| >>> I've got access to an '88 K2500, '90 C2500, '93 C1500, '98 C2500,
| >>> and a '01 K1500.... so far the '01 hasn't had the fuel pump fail on
| >>> it.. yet. both the '88 and the '90 on their third pumps.
| >>>
| >>> -Bret
| >>>
| >>
| >> My 94 K1500 is doing fine at 86,000 on its original pump. You must
just
| >> be hard on equipment!
| >>
| >>
| >> Matt
| >
| >Yep, he probably drives around on "E" alot
| >
| A lot of people are convinced it costs more to keep the top 1/4 of the
| tank filled than the bottom 1/4.

 

I ALSO have that same truck but i never run the tanks past 1/2 then i switch
over.....great truck it had 86000 on it when i pick it up,,,it has about
107000 now never had a problem with the pump


I've got an '87 F150 with duel tanks and I reguarly run the rear tank dry
before switching to the front tank. Its got 133K miles on it now. I bought
it with 85K miles on it. I'm sure they're both origional pumps.

I get at least 250 on one tank and start thinking of fiiling it up with 200
miles on the second tank. Usually fillup with 33 gallons out of 38 gallons
possible.


| On Sat, 06 Nov 2004 17:31:18 GMT, "Scott M" <>
| wrote:
|
| >
| >| >> Bret Chase wrote:
| >>> On Fri, 05 Nov 2004 18:01:27 -0500, Matt Whiting
| >>>
| >>>
| >>>>:|Scott M wrote:
| >>>>:|
| >>>>| >>>>:|> :|>>Scott M wrote:
| >>>>:|>>
| >>>>:|>>
| >>>>:|>>>| >>>>:|>>>
| >>>>:|>>>
| >>>>:|>>>> wrote:
| >>>>:|>>>>
| >>>>:|>>>>
| >>>>:|>>>>
| >>>>:|>>>>>On Tue, 02 Nov 2004 16:53:18 -0500, Matt Whiting
| >>>>:|>>>>>
| >>>>:|>>>>>
| >>>>:|>>>>>
| >>>>:|>>>>>>Alex Rodriguez wrote:
| >>>>:|>>>>
| >>>>:|>>>>>>>this also means you should keep your tank level from getting
too
| >>>>low. :|>>>>>>>Otherwise you can shorten the life of your pump.
| >>>>:|>>>>>>
| >>>>:|>>>>>>Another urban legend.
| >>>>:|>>>>>>
| >>>>:|>>>>>>Matt
| >>>>:|>>>>>
| >>>>:|>>>>>Not totally. Running the pump VERY low on fuel reduces cooling
and
| >>>>:|>>>>>lubrication and CAN hasten the pump's demise.
| >>>>:|>>>>
| >>>>:|>>>>Absolutely not on lubrication. It is impossible not to have
| >>>>gasoline in :|>>>>the pump at the bearings if the vehicle is running
off
| >>>>of fuel from the :|>>>>pump since the bearings (more accurately,
bushings
| >>>>in almost all consumer :|>>>>vehicles)are within the internal pump
volume
| >>>>(the shaft and bearings are :|>>>>surrounded by the fuel as it flows
thru
| >>>>the pump. If there's no gasoline :|>>>>at the bearings, neither is
there
| >>>>fuel getting to the engine, i.e., the :|>>>>engine will not run, and
most
| >>>>likely neither will the pump for very long :|>>>>at all (and that's
not
| >>>>"low" in fuel - that's "out of" fuel). The :|>>>>bearings running dry
or
| >>>>even slightly low is not a credible situation at :|>>>>all - not even
at
| >>>>the point that the engine cuts off due to your "running :|>>>>out of
gas"
| >>>>(at which time the pump still is full of fuel).
| >>>>:|>>>>
| >>>>:|>>>>As far as the cooling aspect, yeah - you might have that on a
| >>>>:|>>>>technicality, but you do have a steady cool volume of the fuel
| >>>>running :|>>>>thru the complete internals of the pump/motor assy. So,
| >>>>probably the :|>>>>outside surface of the pump (case and magnets,
which
| >>>>are on the inside :|>>>>surface of the case) will rise a few degrees,
but
| >>>>the insides (armature, :|>>>>brushes, bearings/bushings) would rise
| >>>>*very* little (due to the volume :|>>>>flow rate of ambient
temperature
| >>>>fluid that bathes those components. I :|>>>>doubt that those thermal
| >>>>effects are at all significant in pump life.
| >>>>:|>>>>
| >>>>:|>>>>IMO...
| >>>>:|>>>>
| >>>>:|>>>>Bill Putney
| >>>>:|>>>
| >>>>:|>>>
| >>>>:|>>>You are forgetting when the tank is very low the pump can "suck
air"
| >>>>on :|>>>corners, hills, stop and go...and that is very hard on a vane
| >>>>type pump. :|>>>It seems to kill GM pumps alot more than Fords. I just
| >>>>helped a friend :|>>>change one on his blazer-he said- I thought I was
| >>>>just out of gas, the :|>>>tank was low and I was trying to make it to
the
| >>>>next gas station. I guess :|>>>it could have been coincidence, but I
| >>>>really doubt it IMO.
| >>>>:|>>
| >>>>:|>>When you say "vane" type pump, is that roller vane, or some other
| >>>>type of :|>>vane?
| >>>>:|> :|> :|> I dont really think it would matter. Even if it was some
type
| >>>>of turbin or :|> what I think they call a slide? I believe there are
3
| >>>>problems in the case :|> I mentioned above. One is cooling by the
fuel,
| >>>>another is lubrication by the :|> fuel, and the worst one of all I
think
| >>>>is the fatigue from a gas to a liquid :|> instantly. Think of your
boat
| >>>>prop. If it catches air, the force when it :|> hits water again is
| >>>>sometimes enough to break the shear pin in the prop, :|> almost like
| >>>>hitting a log in the water at full throttle. I would say the :|>
problem
| >>>>is the higher the speed the pump turns, the more the problems with :|>
| >>>>all the above. Does that make since or do you all think I'm
caaaraaazy?
| >>>>
| >>>>:|
| >>>>:|I don't think you are crazy, I just don't think the problems you
| >>>>:|mentioned are significant. If they were, you'd see cars littering
the
| >>>>:|road side with failed fuel pumps, and that just isn't happening.
I've
| >>>>:|owned several cars over the last 20 years that had electric fuel
pumps
| >>>>:|and I've yet to have a single failure.
| >>>>:|
| >>>>:|
| >>>>:|Matt
| >>>
| >>> I've got access to an '88 K2500, '90 C2500, '93 C1500, '98 C2500,
| >>> and a '01 K1500.... so far the '01 hasn't had the fuel pump fail on
| >>> it.. yet. both the '88 and the '90 on their third pumps.
| >>>
| >>> -Bret
| >>>
| >>
| >> My 94 K1500 is doing fine at 86,000 on its original pump. You must
just
| >> be hard on equipment!
| >>
| >>
| >> Matt
| >
| >Yep, he probably drives around on "E" alot
| >
| A lot of people are convinced it costs more to keep the top 1/4 of the
| tank filled than the bottom 1/4.