used fuel pump test.?

[claybill]

my fuel pump on the 41 has a vacuum line to and from it...seems no purpose.

any reason? anyway the thing gave out this afternoon and the diaphragm electric back-up puked as well.! luckily a friend lived close by and a little gas down the carb and it started right up...

NOW... i have 3-4 used fuel pumps, new style and old style, seems A YEAR AGO SOMEONE SAID blow into one end and see if it passes air, then blow in the other end and see if it passes air....etc..etc one should be blocked and the other end should blow thru...correct.?.if both ends 'blow' thru its no good...etc

any help here.? WHICH END IS WHICH.?

bill

[Rusty O'Toole]

Is it a double decker fuel pump? The upper story is for the wipers. It is a vacuum pump to supplement engine vacuum. Ports should me marked "wiper" and "manifold" or words to that effect. Hook it up and your wipers will not stall out on hills.

You should be able to blow through in the direction of fuel flow but not the other way, if the valves are working. This does not tell you if the diaphragm is shot. Depends how old they are, most fuel pumps rebuilt since the 80s are immune to gasohol, older ones soon fail on today's so called gas.

[claybill]

thanks Rusty....perfect info.!

bill