3406b missing allen screws from pump??

I have had the tach and speedo do that at different times thru the years I have had my 85. Both times it was at the 2 wire plug in under the hood on the left side where the wires come thru the fire wall. The wire will break inside the insulation.

 

So I was driving early this morning thinking about your issue. What kind of oil or lubricator have you run through that fuel pump since you've owned the truck?

 

Yeah I mean for the fuel. Might not be a horrible idea to run some marvel mystery oil through the fuel pump. I do it once every month or two, just dump the oil in the fuel tank. It's important to keep the fuel pump lubricated, today's fuel doesn't provide enough. Makes sure all the valves and plungers are operating fully.

 

I agree with marvel mystery for sure. Also TSC has some stanadyne fuel treatment. I am against any form of mechanic in a can, however I seen with my own eyes what it done for a CAT backhoe. Only time I ever doubted my pump man. It was a foolish moment

 

Yeah I'm also not a huge believer in buying all kinds of products and additives but the old Cats do benefit from some form of pump lubricant.

 

I have had pretty good luck with just regular old two stroke oil, I use it in both my 3406 and 855.