I replaced the fuel pump on the B&S engine in my John Deere lawn
tractor. But, it doesn't pump fuel and I wonder if I have to prime
it. Fuel is reaching the input side via the filer, but nothing comes
out of the output side. There is a third hose on the pump which I
presume is vacuum or pressure that make the pump work. Can anyone
help? TIA

Whats your "model - type -code" numbers and i'll check out the diagrams / tech for you

Lawnmower World - The home of Quality garden machinery

On Sep 4, 5:58*pm, *Mechanic*
wrote:
'Stubby[_3_ Wrote:

;899385']I replaced the fuel pump on the B&S engine in my John Deere
lawn
tractor. *But, it doesn't pump fuel and I wonder if I have to prime
it. *Fuel is reaching the input side via the filer, but nothing comes
out of the output side. *There is a third hose on the pump which I
presume is vacuum or pressure that make the pump work. * Can anyone
help? *TIA

Whats your "model - type -code" numbers and i'll check out the diagrams
/ tech for you

'Lawnmower World - The home of Quality garden machinery'
(http://www.jungle-busters.co.uk)

--
*Mechanic*

Thanks. The tractor is a John Deere LA125. jdparts.com has a
diagram and shows the fuel pump, but it is not very helpful (to me at
least).

Stubby wrote:
I replaced the fuel pump on the B&S engine in my John Deere lawn
tractor. But, it doesn't pump fuel and I wonder if I have to prime
it. Fuel is reaching the input side via the filer, but nothing comes
out of the output side. There is a third hose on the pump which I
presume is vacuum or pressure that make the pump work. Can anyone
help? TIA

That third hose connects to the crankcase and uses the alternating
pressure vacuum to operate the pump diaphragm. So make sure that third
hose is connected and in good shape.

Priming it won't hurt but should not really be necessary.

--
Art

On Sat, 4 Sep 2010 06:13:04 -0700 (PDT), Stubby
wrote:

I replaced the fuel pump on the B&S engine in my John Deere lawn
tractor. But, it doesn't pump fuel and I wonder if I have to prime
it. Fuel is reaching the input side via the filer, but nothing comes
out of the output side. There is a third hose on the pump which I
presume is vacuum or pressure that make the pump work. Can anyone
help? TIA


You are corect in the third port goes to a vacuum port, so to speak.
The pulses from the engine crank case are what makes the pump
diaphragm "flutter" thus pumping the fuel. Check that your hoses are
in good condition first as that woud be the most likley suspect at
this point, and generally there is no need to prime the pump. If all
the fuel drained back into the tank when you changed the pump it might
take a bit to get it back up to the pump.......Midnite

On Sep 5, 6:24*pm, wrote:
On Sat, 4 Sep 2010 06:13:04 -0700 (PDT), Stubby

wrote:
I replaced the fuel pump on the B&S engine in my John Deere lawn
tractor. *But, it doesn't pump fuel and I wonder if I have to prime
it. *Fuel is reaching the input side via the filer, but nothing comes
out of the output side. *There is a third hose on the pump which I
presume is vacuum or pressure that make the pump work. * Can anyone
help? *TIA

You are corect in the third port goes to a vacuum port, so to speak.
The pulses from the engine crank case are what makes the pump
diaphragm "flutter" thus pumping the fuel. Check that your hoses are
in good condition first as that woud be the most likley suspect at
this point, and generally there is no need to prime the pump. If all
the fuel drained back into the tank when you changed the pump it might
take a bit to get it back up to the pump.......Midnite

Once I got some good light I found the vacuum line had fallen down in
the crack behind the engine. Once reconnected, the mower worked just
fine. Thanks!

LOL It's funny sometimes to fix something you need to break it down completely!