[Healeys] su pumps again

[Bob Spidell]

Stumbled across this the other day (they also have them for later cars): 

http://www.bpnorthwest.com/austin-healey/bn1-bn2/fuel-system/fuel-pump-electronic-dual-polarity-bn1-bn4-mg-tf-mga-mgb-to-64.html 

NFI, and I've never used one. 

Bob 

----- Original Message -----



My car had a generic 'modern' plastic pump which worked fine but isn't 
quite kosher so I got a new SU pump from Burlen and that is where I 
discovered the diaphragm issue. It really does let quite a bit of 
petrol smell through- enough for me to take it apart and look for the 
leak. Burlen sent a replacement diaphragm which is, of course, no 
better. 

If you have a used 60 year old triple layer diaphragm for sale I'd be 
interested in upgrading my new one! 

The best design I have seen is an Italian copy that had a single layer 
clear plastic diaphragm and also a plastic toggle inside the points 
which is so much simpler than the mousetrap. Been in a Bn2 for longer 
than I have been alive and only needed a replacement inlet fibre 
sealing washer to stop a leak. 

Andy. 

On 11/23/16, Oudesluys <coudesluijs at chello.nl> wrote: 
> I have not come across the single layer diaphragms. I have seen offered 
> on ebay new dual layer ones from China and the UK. So far I have had 
> enough scrap pumps of the wrong type to provide enough good triple layer 
> diaphragms for the ones that were fit for a rebuild as the so called 
> High Pressure type I want, AUF301 or W/AZX1307/8 or equivalent, so I 
> have no experience with the modern replacements. 
> The permeation of petrol will probably very, very little if any, so I 
> would not worry about it. Some modern rubbers withstand all fuels and so 
> as long as these are used it will probably be OK. Time will tell. Anyway 
> the pumps cast iron coil housing and the space on top under the bakelite 
> cap over the points assembly is vented. 
> As the old triple layer diaphragms seem to last for ever I would not 
> replace them other then when they have become hard and cracked or when 
> the thin plastic membrane that keeps the petrol away from the rubber is 
> damaged. 
> Kees Oudesluijs 



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