type 4 fuel pump saga

Discussion in 'Mech Tech' started by andyv, Jun 22, 2022.

  1. I'm posting some pictures of fuel pumps for comment. The first four pics are of the stock pump. There is an operating lever pin which screws in the base of the pump. The other side is solid casting. When in place this is very good at preventing leaks as the screw head is on the top side when on the engine.

    The other two pictures are of a replacement pump. If you want to buy a new type 4 pump this is what all the usual sellers provide. Unfortunately the pin is just a knock in interference fit, which does leak and more importantly in my case worked its way loose after a month. I currently have this pump on the engine but I fitted a pin and circlip from a type 1 pump, so it won't fall out but unfortunately it drips oil, not a lot but enough to get mentioned as an advisory in the MOT. Bentley shows the early type 4 pump with this type of fitting.

    I switched to the second pump because the original was leaking fuel from the top cover, seen in pic 3. Not a lot but enough to cause a smell parked in the garage. In the picture it's not tightened down but you can just about see that the metal is slightly warped. I've shown the innards on the next photo. I replaced the gasket, tried flatting down the ring on the top cover, even swapped over the top cover from another pump. Also adding a fine film of Hylomar cement (two types) to the outer edge.

    So I have choice between dripping oil or fuel. At the moment it's oil, which is probably for the best.

    Yes I know I could have an electric pump, but has anybody satisfactorily fixed the original?
    2022-06-22 001 001 (600x800).jpg 2022-06-22 001 002 (600x800).jpg 2022-06-22 001 003 (800x600).jpg 2022-06-22 002 001 (600x800).jpg 2022-06-22 001 004 (800x600).jpg 2022-06-22 001 005 (800x600).jpg
     
    Spacecowboyuk likes this.
  2. Milky

    Milky Sponsor

    I have an original pump with a worn out diaphragm if that's any help to you ?
     
  3. That would be great. PM sent.
     
  4. Milky

    Milky Sponsor

  5. The pin coming out on the repro is a good result, on mine the brass outlet came off the pump. Think it had Mega on it ? Mega Sh1te
     
  6. mikedjames

    mikedjames Supporter

    Its a pity - it looks like the SSP Type 4 pump is just a re-badge of some body else's. While the SSP brand Type 1 pump is quite different to the usual, and nicely put together but really too tall if you have a progressive carburettor. (my inlet manifold has a hole in it covered with fibreglass that is moulded round the top of the pump body, the pump is about 5mm too wide at the top.)
     
  7. I think I may have a couple of original pumps somewhere in the garage which, if memory serves correctly, I'm sure are in good nick. Let me know if you need.

    I have an engine that won't accept mechanical pumps. I'm having my own electrical pump problems currently
     
    paradox and andyv like this.
  8. Many thanks for the offer Foxy. I have an original one on its way to me at the moment so I’ll be in touch if I can’t make a good one out of all the bits.
     
    paradox likes this.

  9. If anyone else is in need, let me know.
     
    andyv likes this.
  10. OK a follow up. I think I've fixed it. To cut a long story short, I've found that my pump had been fitted with a type 1 top diaphragm and non return valve. This only fits if you remove a brass guide plate, though it must have given years of adequate service as I've owned the bus for 19 years. I've swapped parts from pumps provided by @Paul L and @Milky, and bench tested with a head of petrol onto each of the pipes. The incoming flow doesn't cause a leak, but I think the fuel standing in the hose up the the carbs was coming back through the non return valve and seeping through the top plate.

    I've now swapped over a good original top diaphragm and cut off valve with the correct brass guide and refitted the pump to my bus and it's working fine.

    Rebuild kits are no longer available for this pump AFAIK, though some bits will fit from the type 1 kit.
    IMG_5189.1.JPG
     
    paradox and mcswiggs like this.
  11. mcswiggs likes this.

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