Thanks for all the previous tips on changing the C3 fuel pump. I’ll try to summarize the entire job the way I found it to be easiest to do on my 1981 L81 350ci. It is not a hard job if you do it right, just tedious.
1. Jack up the front of the car to lift the tires about 8”-10” off the floor, turn the wheels full over to the left, then block up under the front tires and lower the jack until the tires rest onto the blocks.
2. Get at least a 8’ length of 3/4” or smaller garden hose and siphon all the gas out of the gas tank.
3. Pop the distributor cap hold downs and carefully bump the engine over by pecking the starter, checking under the cap until the distributor rotor is pointed at the #1 spark plug wire. It doesn’t have to be exact, just close. (This will position the cam so the pump will be easiest to reinstall.)
4. Remove the two formed rubber fuel hoses from the steel fuel lines coming from the tank.
5. Remove the steel fuel line at the carb coming from the fuel pump. (Hold backup with a wrench on the fuel filter housing then don’t forget to remove fuel filter housing and replace the paper fuel filter. BE CAREFUL NOT TO DAMAGE THE FUEL FILTER HOUSING GASKET)
6. Remove steel fuel line from the fuel pump.
7. Using a long (18”) 1/4” drive socket extension and 7/16” socket insert it thru the cutout in the right wheel well adjacent to the fuel pump and remove both fuel pump attach bolts. A 3/8” drive socket will be more difficult to make work but it will.
8. Remove the fuel pump by maneuvering it out underneath the car.
9. Remove the two fuel pump mounting plate bolts and remove the plate being careful to catch the push rod as it will tend to slide out.
10. Remove the short 3/8”-16 bolt (that is at the same level as the fuel pump attach bolts but on the front of the engine adjacent to the fuel pump) and replace it with a 3/8”-16 x 1-1/4” grip bolt that you will have to provide.
11. Clean and slide the push rod back into its hole (making sure to insert it the same way it came out) all the way in until it bottoms out on the cam and hold it there. Then finger tighten the longer bolt you just installed until it contacts the push rod. FINGER TIGHT ONLY! I used a long socket to hand tighten the bolt.
12. Clean the gasket surfaces on the fuel pump mounting plate and engine block and reinstall the mounting plate with a new gasket.
13. Remove the fitting from the old pump (if there is one) and reinstall in the same orientation on the new pump.
14. Permatex the new gasket onto the fuel pump and let it set up a few minuets. Run both bolts thru the gasket which will hold them in position for installation.
15. Maneuver the fuel pump into position and carefully install the bolts evenly by inserting the long socket wrench extension back thru the wheel well cutout adjacent to the fuel pump. Run the bolts in evenly then torque the bolts.
16. Unscrew the long bolt holding the push rod in place and replace it with the original short bolt. (DON’T FORGET TO DO THIS !!!)
17. Install the steel fuel line to the pump.
18. Install the two formed rubber fuel lines onto the fuel pump then onto the steel fuel lines from the tank. (Use new formed hoses from Eckler’s and new clamps. Don’t try to use regular fuel hose, it will crimp, the bends are too tight.) If one of the hoses contacts the car frame, tie-wrap it back to the fuel pump just enough to clear so it doesn’t rub on the frame.
19. Install the steel fuel line at the carb making sure the fuel filter housing is tightened properly first.
20. Fill the gas tank back up.
21. Start the car and check for leaks. VERY IMPORTANT !!!