128 Fuel Pump question

My pump started spitting fuel so since I have a new diaphragm handy I thought Id start by pulling the old one and looking at it for signs of wear. I thought I'd be slick and do this with the pump still in the car but I cant pull the diaphragm out. My manual doesnt have a diagram of the pump so I'm not sure what's holding it in..

Any ideas?

Also, on more than oe occasion with a full tank sitting in direct sunlight my gas tank has spewed fuel thru the cap. This happened the day before the pump bit the dust. Any thoughts on the possible relationship between these events?

thanks all!

What parts of the original evaporative emissions system are in place? In stock form, the tank is sealed and any pressure/fumes are routed to the charcoal canister and it alos allows makeup air to enter the tank to replace fuel as it's consumed. If you're missing these parts, or have a plugged or pinched line, this can be the result.

Hi Greg, It seems theyre all in there iirc. I replaced all the lines at the tank over a year ago and I DID have the pinched line issue at that time. i was not able to fill the tank as the fuel started spewing as i was filling it. I went back in, unkinked the line and all was fine. Is it possible that an overfill situation could plug the vent line and the heat of direct sun could cause the pressure build up?

Possible I guess...

It's possible I guess, in that if you fill past the first auto-shutoff you can fill past the tank system's ability to compensate for temperature expansion, etc. On the wagon, is the tank below the back seat or farther back? There may not be much "wiggle room" in this regard for wagon.

Sure sounds like some sort of vent blockage though.

The tank is all the way at the rear of the car. I dont have a venting gas cap which i am going to add.

Spewing gas

As a first test, leave the gas cap loose to fully vent the tank. If this stops the spewing issue then you know you have a venting problem.

carl

Fuel Pump

Don't know if this helps or not: