Fuel Problem

[hsvt95]

Hey guys, new member here, had my truck since 2017. My front tank is sending fuel to the rear tank, and the other day I came outside to my truck spitting fuel out the fuel cap in the rear. Im leaning towards a new rear fuel pump because when I switch the the rear pump, the truck runs horrible. Any ideas?

 

[Red one]

Search fuel cross flow issues on this site and there are tons of info on this issue

 

[bobwhite]

shuttle valve diaphragm in the rear fuel pump canister is possibly ruptured or it could be a problem with the check valve at the rear pump. most likely rubber diaphragm. very common failure.