In-the-tank fuel pumps cause death and destruction

On Fri, 29 Oct 2004 23:35:47 -0400, "Thomas Moats" > wrote:

>
> wrote in message
.. .
>> On Fri, 29 Oct 2004 22:54:06 -0400, "Al Smith" >
>> wrote:
>>
>> >Wait a minute. Maybe there are shortcuts in some cases - and I have only
>> >done
>> >it once - but every fuel pump replacement I have heard about
>> >involves dropping the tank.
>> >
>>
>> None of the intank fuel pumps used on carbureted Toyota vehicles
>> required removal of the tank to replace. All had screwed on access
>> covers either in the trunk or floor under the rear seat to access the
>> fuel sender.fuel pickup/fuel pump.. Many other vehicles were built the
>> same.
>>
>> Many of today's vehicles DO require dropping the tank - and MANY of
>> those tanks are plastic, not steel.. Many of them have quick
>> disconnects to disconnect the fuel lines, and if less than 1/4 full
>> pose a very limitted danger of spillage when removing. They are also
>> usually relatively simple to drain with a proper fuel transfer pump,
>> either electrical, air powered, or manual.
>>
>> Most fuel injected vehicles can be easily drained from under the hood
>> by connecting the transfer pump to the service valve on the fuel rail
>> - without getting ANY fuel or fuel vapours into the shop, and with NO
>> danger of fire.
>
>If you have about a week to wait for the fuel to tranfer........

No,, about half an hour maximum will empty a 72 liter tank - and
totally unmonitored, so you can do another job while it is being
drained. The schrader valve is removed to remove a significant amount
of restriction from the line.
>
>
><snip>
>

On Fri, 29 Oct 2004 23:35:47 -0400, "Thomas Moats" > wrote:

>
> wrote in message
.. .
>> On Fri, 29 Oct 2004 22:54:06 -0400, "Al Smith" >
>> wrote:
>>
>> >Wait a minute. Maybe there are shortcuts in some cases - and I have only
>> >done
>> >it once - but every fuel pump replacement I have heard about
>> >involves dropping the tank.
>> >
>>
>> None of the intank fuel pumps used on carbureted Toyota vehicles
>> required removal of the tank to replace. All had screwed on access
>> covers either in the trunk or floor under the rear seat to access the
>> fuel sender.fuel pickup/fuel pump.. Many other vehicles were built the
>> same.
>>
>> Many of today's vehicles DO require dropping the tank - and MANY of
>> those tanks are plastic, not steel.. Many of them have quick
>> disconnects to disconnect the fuel lines, and if less than 1/4 full
>> pose a very limitted danger of spillage when removing. They are also
>> usually relatively simple to drain with a proper fuel transfer pump,
>> either electrical, air powered, or manual.
>>
>> Most fuel injected vehicles can be easily drained from under the hood
>> by connecting the transfer pump to the service valve on the fuel rail
>> - without getting ANY fuel or fuel vapours into the shop, and with NO
>> danger of fire.
>
>If you have about a week to wait for the fuel to tranfer........

No,, about half an hour maximum will empty a 72 liter tank - and
totally unmonitored, so you can do another job while it is being
drained. The schrader valve is removed to remove a significant amount
of restriction from the line.
>
>
><snip>
>

Bill Putney wrote:
> Ken Weitzel wrote:
>
>>
>> Bill Putney wrote:
>>
>>> Ken Weitzel wrote:
>
>
>>>> I do have one question though that I'd like to ask if
>>>> I may? When I have a quarter tank of fuel left, what
>>>> exactly occupies the remaining space?
>
>
>>> If I see where you're going with this, the inside of the fuel pump
>>> (where all the electrical commutation/sparking takes place) is 100%
>>> full of liquid fuel under all conditions. Missing only one
>>> ingredient for fire or explosion: air/oxygen. Comforting thought, eh?
>>>
>>> To answer your question: air (but all the arcing and sparking is
>>> inside the pump with only liquid fuel).
>

wouldn't the arcing be only where the actual motor assembly would be?
could this not be a sealed unit? Would you even want gas in there? I
would think gas does a poor job of lubrication - you'd have some kind of
grease in the actual motor assembly, wouldn't you?

the gears that pump the gasoline won't be arcing...

fwiw, my fish tank pump uses a sealed pump assy with a magnetic drive
assembly - no chance of water touching the electrical parts.

Ray

Bill Putney wrote:
> Ken Weitzel wrote:
>
>>
>> Bill Putney wrote:
>>
>>> Ken Weitzel wrote:
>
>
>>>> I do have one question though that I'd like to ask if
>>>> I may? When I have a quarter tank of fuel left, what
>>>> exactly occupies the remaining space?
>
>
>>> If I see where you're going with this, the inside of the fuel pump
>>> (where all the electrical commutation/sparking takes place) is 100%
>>> full of liquid fuel under all conditions. Missing only one
>>> ingredient for fire or explosion: air/oxygen. Comforting thought, eh?
>>>
>>> To answer your question: air (but all the arcing and sparking is
>>> inside the pump with only liquid fuel).
>

wouldn't the arcing be only where the actual motor assembly would be?
could this not be a sealed unit? Would you even want gas in there? I
would think gas does a poor job of lubrication - you'd have some kind of
grease in the actual motor assembly, wouldn't you?

the gears that pump the gasoline won't be arcing...

fwiw, my fish tank pump uses a sealed pump assy with a magnetic drive
assembly - no chance of water touching the electrical parts.

Ray

wrote:
>
> Externally mounted pumps, unless engine driven and engine mounted, are
> open to corrosion which can perforate the pump case, allowing it to
> leak fuel. The connections are also open to corrosion - and they are
> exposed to air, which contains oxygen, which gasoline requires inorder
> to burn.. Also, fuel pumps are MUCH better at pushing fuel than
> sucking it, and fuel vapourizes at a lower temperature when under low
> pressure - so vapour lock is ALWAYS a possibility with front mounted
> pumps - while almost unheard of with intank "pusher" pumps.
>

One other problem with external pumps. Noise. The tank acts as a nice
muffler for the pump while. Plus the rubber on the tank straps deaden
the sound even more.

My buddy's Nova with an external Holley electric pump whines.
Fortunately, you can't hear it over the exhaust.

Ray

wrote:
>
> Externally mounted pumps, unless engine driven and engine mounted, are
> open to corrosion which can perforate the pump case, allowing it to
> leak fuel. The connections are also open to corrosion - and they are
> exposed to air, which contains oxygen, which gasoline requires inorder
> to burn.. Also, fuel pumps are MUCH better at pushing fuel than
> sucking it, and fuel vapourizes at a lower temperature when under low
> pressure - so vapour lock is ALWAYS a possibility with front mounted
> pumps - while almost unheard of with intank "pusher" pumps.
>

One other problem with external pumps. Noise. The tank acts as a nice
muffler for the pump while. Plus the rubber on the tank straps deaden
the sound even more.

My buddy's Nova with an external Holley electric pump whines.
Fortunately, you can't hear it over the exhaust.

Ray

<snip>
> >If you have about a week to wait for the fuel to tranfer........
>
> No,, about half an hour maximum will empty a 72 liter tank - and
> totally unmonitored, so you can do another job while it is being
> drained. The schrader valve is removed to remove a significant amount
> of restriction from the line.
> >
> >
> ><snip>
> >
>

That is bull.

<snip>
> >If you have about a week to wait for the fuel to tranfer........
>
> No,, about half an hour maximum will empty a 72 liter tank - and
> totally unmonitored, so you can do another job while it is being
> drained. The schrader valve is removed to remove a significant amount
> of restriction from the line.
> >
> >
> ><snip>
> >
>

That is bull.

On Sat, 30 Oct 2004 03:15:52 GMT, Ken Weitzel >
wrote:
><snip>
>Hi Bill...
>
>I'd have to be several kinds of fool to debate you
>given your experience.
>
>Perhaps though, we should together design a new
>system? I'm thinking of gravity...
>
>Ken

VW beetle had the gravity feed. Not sure that I'd want a gravity
feed if I was involved in an accident....... ;-)

On Sat, 30 Oct 2004 03:15:52 GMT, Ken Weitzel >
wrote:
><snip>
>Hi Bill...
>
>I'd have to be several kinds of fool to debate you
>given your experience.
>
>Perhaps though, we should together design a new
>system? I'm thinking of gravity...
>
>Ken

VW beetle had the gravity feed. Not sure that I'd want a gravity
feed if I was involved in an accident....... ;-)