Question
gas line
QUESTION: 1976 mgb fuel pump has a small plastic pipe coming from it - gas is leaking from it when the car is running - at this time, it's stuck in a hole in the frame; I'm sure it goes somewhere else...got any ideas? I have pics, not sure how to send them...
ANSWER: Hi Wayne. The small plastic pipe from the lid of the pump is just a breather pipe. It should go up inside the boot (trunk) through a small grommet, and it is terminated with a small plastic T-piece to stop it pulling back through the grommet. The pipe and T-piece are standard screenwash tubing, nothing special. If gas (petroleum) is coming through the tube, then the diaphragm inside the pump has split, so the pump is shot. If you know what you are doing you can fit a new diaphragm, but you will probably need new points as well, so I would advise you to fit a new fuel pump.
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QUESTION: Terminated in the boot exactly where? There's a small vent
pipe on the boot side of the pump with nothing on it - does
it connect there? How do I know if I'm replacing the pump with one that will work? They advertise a $100.00 replacement fuel pump and a 159.95 SU fuel pump - (Victoria British LTD)...does it matter which one I buy? Is the 100 just as good as the 150 dollar one?
ANSWER: Hi Wayne. With a 76 B the plastic head of the pump should be in the boot. From your photo I see that yours is underneath the car. That arrangement ended in 1975. Maybe your car was built late 1975. The plastic pipe goes up almost vertically and enters near the back of the boot behind the spare wheel but up on the ledge, a bit to the right of centre.
I buy my fuel pumps from Burlen Fuel Systems of Salisbury UK. They own the sole manufacturing rights to all SU products (pumps, carburetters and spare parts). I bought a reconditioned pump last week for under £50 UK pounds. My guess is that the USA dealers have a big mark-up.
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boot picture
QUESTION: I'm looking at the order book for fuel pumps and trying to determine which one to purchase - there is a plastic head pump in the boot (pic enclosed) and causing me all kinds of confusion. Based on our conversations, and from the pictures, are there actually two vents coming from the pump? In the pic, the one with the black hose is, as shown, in the boot and the previous pictures taken from beneath the car show the one I'm asking about. Appreciate what you've done so far - you're a very patient expert and I appreciate your expertise...going to try the attachment again...thanks...
Wayne
Answer
SU AUF300 type fuel pu
Hi Wayne. On some pumps there are two vents, one in the cap and another on the body. They should both vent into the boot (trunk). Since the plastic head is already in the boot, it does not require a plastic pipe. The second vent, on the body, does require a vent pipe. The purpose of the plastic T-piece is simply to stop the pipe from pulling through the grommet. If you search the boot above the pump you may find a grommet (often brown coloured) with a T-piece still stuck into it. I attach a photo of a new pump which I bought 3 weeks ago. I have attached two plastic pipes so you can see where they go. Do not join the two breathers together because that would close the system and prevent the pump from breathing.
