Fuel Pump Question

Joined
Nov 29, 2005
Messages
16
I removed my 1977 FJ40 mechanical fuel pump for a cleaning and noticed that there was a small hex screw on one side of the lower body and not the other. There is a threaded hole there so I am guessing one fell out. The fuel pump is a "Nikki".

What purpose do these screws serve and are they both necessary?
 
Joined
Nov 29, 2005
Messages
16
The side towards the rear of the vehicle has a hex screw. The side towards the front does not.

Should I chase down a hex screw or not worry about it?
P1010020.JPG
P1010021.JPG
 
Joined
Jul 7, 2004
Messages
1,516
Location
EVERGREEN, CO, USA
This is an air pressure equalization hole. If the pump wears out it also acts as a weep hole an gas runs out and smells the FJ up real nice, letting u know there is something wrong under the hood.

...
 
Joined
Nov 29, 2005
Messages
16
Thanks, I'll remove it.

I wonder why the holes are threaded. Another great mystery.
 

Trollhole

THC
Supporting Vendor
Moderator
Joined
Mar 6, 2005
Messages
21,016
Location
Mauldin, SC
Website
forum.ih8mud.com
There has to be a reason there is a screw there. Maybe it keeps fuel from exiting the wrong place. Maybe it was desiged for more than one vehicle in mind so sides might be different.

If it's working, and there is another weep hole already what is the advantage of having two.

If it aint broke don't fix it.
 

Users who are viewing this thread

Top Bottom