Electric fuel pump only works when whacked..

Hey guys & gals,

I've got an electric fuel pump failure on a friend's 1977 car, original part, so it's some 45 years old. It will start working when I tap the motor housing a number of times with the handle of a screw driver.. but it's unreliable.

Does that type of failure tell me anything useful? Like is that classic symptoms for "worn brushes" or something? ..and then I can try a rebuild?

The electric motor is in a metal "can" that's crimped shut, so opening it may be one-way trip to the trash bin.
I want to know as much as I can before deciding to open it or not.
OEM replacement is not available, but I've installed a temporary "loaner" to keep the car running.

Thank you,
- Art

yeah worn brushes, or worn to the point it sticks. or swollen.

I am in the camp can't make it any worse so open it up.
if you are lucky it is common parts that can be replaced if he really wants to keep it stock.
otherwise there are any number of suitable replacements.

Probably dirty armature contact area and dry bushings or bearings. Shouldn't be that hard to find an aftermarket replacement. OOPs! got treed.

Thanks guys,
That gives me some confidence to proceed. Yeah, there are lots of aftermarket options. I'm looking into what the OEM flow rate and PSI are.
The spare pump I cobbed in there is really loud, so that's why I'm not done yet.
Cheers,
- Art