Quick Fuel Pump Replacement

[t2jeff]

I have to swap out my stock fuel pump on my 1975 302.

Never replaced it before. Any tips or tricks anyone can tell me to make this a quick job?

My carb currently isn't getting fuel, and after checking the fuel filter and lines, I want to swap the pump before a friend comes to help me on sat.

Thoughts? Thanks in advance.....
Jeff

 

[blubuckaroo]

Get a good one. Find out where the local shops get their parts.
I like to loosen the bolts enough so there's a gap then turn the motor over till the eccentric has the least amount of pressure on it.
Remove the old pump and clean up the block.
Glue the gasket onto the pump with contact cement. (no sealer on the block side)
Put a dab of oil on the lever where it contacts the eccentric.
Install the pump.
The eccentric may still put some pressure on the lever. You'll have to push it into place to get the bolts started.
It's sort of awkward, so have patience.

 

[jckkys]

The stock power steering pump hard to work around. I take mine off the brackets and move it out of the way with the hoses attached. It makes it a lot easier to do a good job installing the fuel pump.

 

[smokinjoe]

If you're installing it and it doesn't seem to be seating, pull it out and bump the starter or rotate the crank a lil.

So you've seen a pic of a fuel pump right? That lil curved arm I'd pressed down as the eccentric spins and presses it down. The eccentric is a metal disc bolted to your camshaft face, as your cam spins, the disc spins and engages the pump.

I always feel knowing how something works helps when doing install or removal, good luck

 

[savage]

;Dfuel eccentric.

 

[t2jeff]

I actually haven't seen one before. Have no idea how/where things are. Thank you for the input.

 

[t2jeff]

Oh, what about the weep hole? Researching here, is that a way to tell if the pump is shot?

 

[Bukin 67]

If you're not getting fuel, the most likely places to start are fuel pump, fuel filter, clogged fuel line or blockage in the tank.

 

[Bukin 67]

Sometimes the pumps are on their way out and pump a little fuel, but not enough to run the motor. With help, you can run a hose from the pump out of the engine compartment into an empty milk jug and turn the motor over to see how much is coming out.

 

[t2jeff]

I just did that. Disconnected the fuel line at the filter in front of the carb, put it in a cup, and cranked away. No gas coming through.

So I assume it's the pump, or the lines, or the switch under the seat. Looks pretty easy to access and test all components. Any more thoughts? Am I missing something?

 

[blubuckaroo]

I'd make sure the pump is bad before replacing it. I've seen some good pumps changed by members on this site. Your problem could be as simple as the selector valve in the wrong position. Every driver in my house has tried to drive with the selector valved to an empty tank at least once. Also, it can take a lot of cranking to prime a dry pump if the line is empty. Did you try pouring a bit of gas down the throat of the carb?

To test the lines, I remove the suction hose from the pump, and put some air pressure into the tank. Depending on your year model, you may need to block the vent hose to the tank. The pressure in the tank should push a good squirt of fuel out the suction hose. If it doesn't, you may have a blocked screen in the tank, or a plugged filter someone has added somewhere. Any air leaks in the suction line would show up now too.
If you do get fuel out the suction, you need to test the pump. Automotive vacuum gauges have a scale for testing fuel pumps. Connect it to the suction port on the pump where you have removed the hose from. Crank the motor over while someone watches the gauge.

Another way, if you don't have the equipment to do those tests, is to stick the suction hose into a gas can and try starting the car. That would eliminate a problem fuel line or plugged tank screen.

 

[t2jeff]

Agreed on not replacing the pump if I don't have to.

I assume when you say remove the suction hose from the pump, that is the hose coming from the tank, correct?

I have tried priming the carb with a little gas. It ran for a bit, then sputters and dies.

I have no idea if my tank has a vent line or breathes through the cap. Where would it be?

 

[TN1776]

I replaced my mechanical fuel pump on the side of a highway in 100 degree weather with cars whizzing by, on my way home from my first 4-wheeling trip in my rig. Its not as bad as you think, but some long extensions on your ratchet and some creative thinking are required.

 

[CopperRanger]

No need to remove the power steering pump if you have one, just more work thats not needed. I have replaced a couple and found that a 1/4" drive set of sockets and extensions are a must, I might have even used a swivel on the end, I can't remember. It is tight with the power steering pump in place, but it can be done.

 

[Blue71]

To check to see if your pump is bad....I usually disconnect the hose from the inlet pump side that comes from the tank. You can lay underneath the Bronco and look up and have access to remove the rubber clamp and hose. Get a 3' ft piece of fuel hose and attach it to the pump where u just removed the rubber hose then drop the other end in a container with some gas in it. I then disconnect my fuel line from where it enters the carburetor and put a towel down over the carb, and distributor. Get someone to crank the motor over with key off. You should be getting fuel pumped pretty quickly into the towel.just tell the person to crank it over a couple at a time so u don't get doused. Make sure key is OFF or it'll pump like crazy. If u get small bits if fuel...pump is bad. If you get healthy squirt or two it's good.

Let us know,

Blue71

 

[t2jeff]

Anyone know the stock size of the rubber fuel line coming from the tank? Im at work and would like to pick up some line at lunch for this weekend!

 

[blubuckaroo]

The suction line is 3/8".

 

[t2jeff]

From what I have seen under my rig, I assume thats OD, and not the ID.

Is the line the same size coming out of the switch under the seat? Looks like there is a larger line from the hardline on the frame to the pump itself. 1/2" maybe?

 

[blubuckaroo]

From what I have seen under my rig, I assume thats OD, and not the ID.

Is the line the same size coming out of the switch under the seat? Looks like there is a larger line from the hardline on the frame to the pump itself. 1/2" maybe?

Tubing is measured by the outside diameter. Hose is measured by the inside diameter.

 

[t2jeff]

Well, everything is now working! It was the fuel pump. Traced and tested everything from the tank forward to the pump before replacing it.

The arm that goes into the pump was worn through, the cam actually wearing away about and 1/8" of metal. The pump actually worked, but there was no arm left for the cam to push on.