Fuel pump swap on a 402

[gmckenny]

I swaped out my fuel pump today on my 72 with a factory 402 BB. It had been leaving big drip spots of fuel after driving and I suspected that it was leaking the $3.50 a gallon life blood out of my fuel tank. Turns out I was right. The fuel pump was failed and it weaped all of the fuel from the carborator on down out each time I parked (except the float bowl so it always fired right up and refilled the line for the next dump). The give away for the failure was the weap hole leaking. I couldn't observe that when it was in the truck. It was clearly clean from leaking on that side after removal. I put vise grips on the two rubber fuel lines (5/16 in line and 1/4 return line) and then cut them. I got wet with fuel. I then disconnected the outlet which is the metal line to the carb. I guess it wasn't completely through it's draining cycle. I should have had a contrainer to catch the $. Instead I tried wearing it. I even screwed it back together at one point until I realized that I had already isolated the fuel tank! It stopped flowing just about the time I started thinking what a good idea it would have been to disconnect the ground on the battery before embarking on this misadventure. At least have a fire extinquisher handy! But no! I went on. I had to remove the plug under the push rod (square head, below the fuel pump) in order to get the mechanical pump arm under the rod. I held the pump suspended by hooking it back up to the metal outlet line to the carb. Then I pushed the rod up with the smallest standard screwdriver in my kit. I confirmed the position with a mirror with a reach arm on it through the plug hole. The I tightened up the two screws to the pump, one click at a time, just like it came off (Damn air conditioning compressor), with the smallest rachet and a swivel and a long 7/16th socket. Board yet? I'm not finished. I tightened the bolts, snugged up the outlet flare nut, tighted the push rud plug and put fresh fuel line tails on the new pump using a socket driver (Sears, brown(3/16?)) to tighten the hose clamps. Then I bravely removed the hose calmps from the vise gripped original lines and pulled off the feeder fully expecting the gush. I didn't have on my safety glasses at the time. I was too lazy to crawl out and locate them in the engine compartment. With fuel stinging in my eyes I attempted to quell the gusher of fuel by connecting the correctly cut and installed new line to the offending outlet. F__k, it had to have taken half a minute! the damn hose was just hung up on the end of the fuel line and it was only maginally accessable to my one tired arm. I was wearing at least 4$ worth of fuel by the time I succeeded in making the love connection. I imagined myself and my truck in a ball of flame. I pulled out from under that truck blinking from the sting and fully away of the danger of my situation only to see some jerk on the sidewalk (oh. did I mention that this was a city street project) ignorantly lighting a cigarette at ten paces. I distanced myself from the truck but quick. After stripping off my saturated shirt in exchange for a rag variety which I had handy, I returned to the project and connected the final line without further excitement. My aqdvice to others. First, the parts shop does not know what fuel pump you have. Chevy used a number of different ones. Eyeball it well before setting out to replace it. Mine was huge with a total of three inlets/outlets and was the third one the parts place provided after a visual inspection of thr removed part($41). Second, but should have been first. Disconnect the negative terminal! Third, safety glasses, and three pieces of cardboard with which to slide under the truck on ( they keep getting saturated with gas). Good luck!

[Green Machine]

Hindsight is always 20/20, but next time you could disconnect the fuel line from the sender behind the seat, or clamp the rubber line under the tank, that will lessen fuel spillage. Been there, spilled that.