AP Fuel pump

[Geoff Dowdle]

Peterg,
You never advised the history of your pump .
Has it ever run correctly on your Bristol ??(it might not be a original Bristol pump)
What model Bristol do you have ?
Please advise the casting number on the lever that runs on the cam ?
I'll check it against an original one .
Have you fitted the diaphragm to the rocking lever correctly by pushing it against the blade spring and turning it through 90 degrees.
Is it the correct diaphragm /kit??
The rubber diaphragm must be set correctly before the fixing screws are tightened.
I doubt that the Standard Vanguard lever will be correct for the Bristol.
I don't believe there is a pressure control device within the pump , the correct stroke of the lever produces the correct pressure, from memory 2.5 - 3 lbs/sq in . Some owners fit a thinner or thicker gasket between the pump body and block to adjust the pressure , but I doubt this will make much difference to the pressure.
My experience with a pump fitted with bent lever only produced about 1 - 1.5 lbs , it was straightened only about 0.040 at the lever and the pressure increased to 3 lbs
Have you got the two valves seated correctly on the gasket and in the correct
position

These pumps are usually trouble free for up to 20 years , eventually the diaphragm rubber hardens .
How do you know that the pump is not producing the pressure ?
Have you put a pressure gauge in the line to check the pressure at about 3000 rpm for about 2 minutes.

If you need to take the car to your daughters wedding you can always fit up a temporary electric pump that produces no more than 3 lbs/sq in

Keep at it, you will fix it , they are a simple pump that work well.

Geoff