mechanical fuel pump

[richard wyatt]

It looks as though the awful modern petrol has rotted the fuel pump on my RP and work on it is required.I have read somewhere it is possible to reinsert the pump in the wrong place in relation to the camshaft-is this a fact,and if so how do I avoid this potential disaster? Alternatively is it possible to change the diaphragm with the pump body remaining in situ-it looks as if one can.All my other sevens have had electric pumps so I am ignorant here.

[Reckless Rat]

The diaphragms sold by the seven workshop are ethanol tolerant and it's quite simple to change one without removing the pump from the crankcase, just undo the 6 screws around the perimeter of the pump. To remove the diaphragm just push down and turn the centre through 90deg. Same to replace.

[David Cochrane]

I found that it was a relatively simple matter to remove the fuel pump to repair it - it's easier (and less strain on the back) to work on it when it's on the bench. If you replace it by pushing it sideways straight on to the crankcase you shouldn't have any trouble. I can also supply a new cork seal for the top cap should you need one.

[Alan]

When fitted, do a couple of gentle turns on the handle. If it’s in the wrong position, the engine will lock up.

[bystander]

Before doing anything, you should check that the pump is a T type. Some, if not all 1933/34 cars originally were fitted with an M type. The pump as a whole is interchangeable, but the parts (including the diaphragm) are not.

[Bob Culver]

And if it is a T type many have the wrong arm which comes periluosly close to slipping off the cam

[circeonya@hotmail.com]

Before removing the pump I always made sure the cam was at maximum push of the lever, then when refitting I could easily tell that I had the lever on the correct side of the cam. I did see a pump destroyed on friends 34 Plymouth by having the lever on the wrong side and he was an apprentice engineer.

[Robin Oldfield]

The arms have a reference number on them.  Can anyone say definitively which is the correct arm?

[Bob Culver]

The shiny wearing area should be more or less in middle of the pad, not at the very tip. (i explored all sorts of far away out of the way places in my car . Had tested crank and axles so was confident .When iItook it apart the pump could have stranded me any time)

[David Cochrane]

I think that the Model T pump lever arm should be No. 856955, or 1524079 (3-bearing engines only).