Fuel Pump type for 41 series 62

[Tom Douglas]

I want to install an electric fuel pump on my 41 - series 62 coupe.  Im not certain whether I have a vacuum or mechanical fuel pump. I was told that if I had a vacuum pump I would need to install a fuel pressure regulator in-line. Is that true? I know that my windshield wipers have a tube connected to the fuel pump... does that mean I have a vacuum fuel pump? If so, when I install these items do I block off the existing fuel pump or leave it attached? Currently, the fuel pump is leaking gas from where it mounts to the block. Will a gasket fix that? Can I find a gasket at a parts store or do I have to buy gasket material and make one myself? When I was in school I was always afraid of asking questions for fear of sounding stupid... Even as an adult I sometimes have that feeling. Im pretty much of a mechanical novice when it comes to my current project, so please, forgive me if I sound like a total dummy.

[Doug Houston]

Theres a first time to learn everything. This is your first turn at fuel pump configurations!!

The pump on that car is a dual action fuel pump. The top part of it is the fuel pump, and the lower part is the vacuum booster. This is why youll see both vacuum and fuel lines connected to it.

From what you say, the pump is bad, and you shouldnt try to run the engine with the fuel pump in that condition without a fire truck parked alongside. If fuel is leaking from the pump, either into the crankcase or out the vent opening in its body, the diaphragm (s) are gone and a fire is awaiting just ahead.

 I have rebuilt several pumps with kits from Antique Auto Parts Cellar. They have a web site, which I cant recall here. Youll spend probably 50 bucks on a kit, and you will have a very good new fuel pump.  If there is a freshly rebuilt pump available, the type number will be 575. Its very doubtful to find a newly rebuilt pump, however. Your best bet is to get a kit and have it rebuilt or do it yourself.

[Tom Douglas]

Thanks for the caution, Doug. I noticed it last Friday when I had a new muffler and tail pipe installed - It made me nervous and I mentioned it to the installer so he was aware of it.  I found the website you mentioned and heres a quote from it... DUAL ACTION (PUMPS FUEL and Boosts Kit:
$39.50 - Manifold VACUUM for wipers and heater controls). My MoToRs AUTO REPAIR MANUAL shows what they call a Combination Pump - a typical AJ construction. Can I assume this is the same as Dual Action? If so, they give a pretty good description of assembling everything... although, I would guess that Antique Auto Parts Cellar would include instructions on re-building the pump as well. How do you feel about installing an electric fuel pump? Would I also need to add a pressure regulator in-line?

[John Washburn]

Tom,

It is always good to have an electric fuel pump installed. With todays gas (it boils at a lower temperature) the chance of vapor lock is greater on hot days. Vapor lock, locks the car up so no gas gets to the carburetor.

On your 41 you need to have around 4 3/4 to 5 psi of output from the fuel pump. So you need to determine the ouput of the electric fuel pump to see if the psi is close, if it is higher then you need the regulator.

I recently wrote a article about fuel pumps for our Cadillacs for out local CLC rag The Dagmar. If your interested I can send you an electronic copy of this.

Finally, if you dont feel comfortable rebuilding your fuel pump there a lots of reputable folks listed in Hemmings who do this for a living. The only concern here is to make sure that the new rubber parts for the fuel pump (no matter who rebuilds it or if you get the kit) are resistant to alcohol, which is now a common ingredient in gas. Alcohol has a tendency to eat the old rubber that was used for years in these old fuel pumps.

Good Luck
John Washburn
CLC #1067

[Tom Douglas]

I relally appreciate your reply, John. I need lots of help with this 41 and you folks are a real blessing to me.

Question: Could I use the electric pump exclusively and eliminate the original? Or is it a necessity I cant/shouldnt live without.

Yes, Id like to have anything you feel would be helpful. In this article, do you describe how to determine the psi output from my fuel pump to see if a regulator is needed?

Ill check out Hemmings...

Thanks again, John

[Doug Houston]

Dual action pumps have a few different names, but your manual is still probably correct.

It is a good idea to have an electric pump beneath the car for priming purposes, especially. It helps get rid of vapor lock, too. Its better to prime a dry carburetor with puel pump current than starter current. The electric pump should have a switch somewhere on the dash to turn it on/off. It shoild be connected to the accessory terminal on the ignition switch.

I wouldnt recommend replacing a mechanical pump with an electric one. They fail too.

One safety consideration here. The mechanical pump isnt built to have pressure on its inlet. The seals on the filter bowl normally can hold with the 5 PSI  from the electric pump, but if the gasket on the bowl is old or dried out, fuel will seep past the bowl gasket, and in terms of fire hazards, that aint good!

By the way, most electric pumps develop about 5 PSI pressure. They stop pumping when the system is full, and there is back pressure. An additional pressure regulator shouldnt be necessary.

[Harry Scott (4195)]

Ive had good luck with rebuilt pumps from Terrill Machine in Texas 254-893-2610. His ad in Hemmings lists rebuilt pumps for $60 exchange.