Mechanical fuel pump question

[ChrisRice]

Well I got my 55 plymouth to start and drive the other day. I came out the next day and wasn't getting fuel, I thought it just needed a little bit of priming. Then my son noticed a hole in the side of the fuel pump. It is a machined hole 7/16 in size. I don't think that it has threads in it, but not 100 percent sure. It seems like maybe a plug goes in there. Not sure if it blew one out, or if it even ever had one. What goes in here, and what is it for. It is right above the fuel outlet.

[ChrisRice]

The Manuel shows a plug goes in that area, but then again my pump doesn't look quite like the one in the Manuel. Would it be metal, rubber, or what? Can't tell from the picture I have if it's threaded or not.

[_shel_ny]

A pic would probably help to get an answer. The pics that I have do not have any place for a plug. Your 55 pump may be different.

Edited May 6, 2014 by shel_ny

[ChrisRice]

It is crusty looking and still on the car. Forgive the crudeness of the pictures and the lighting, but you can see the hole.

[navyboy]

do you have electric wipers, if vacum wipers that could be for the wipers but I dont see how you wouldnt have electric wipers when my 52 does. From the looks of it alone I would just replace it.

[ChrisRice]

It does have electric wipers.. The wipers work fine, and gas shoots out of the hole, so that wouldn't make sense to me.

[ChrisRice]

Ok, so I am an idiot. I went outside and pulled the fuel pump off just to get a better look at it. It was not coming from where I had originally thought. Instead from a hole higher up on the fuel pump. My best guess at this point is that the diaphragm is shot. Is this rebuild able?

[Merle Coggins]

... Is this rebuild able?

 

Yes. Contact the good folks at Antique Auto Parts Cellar for a kit. They're easy to rebuild.

http://www.maritimedragracing.com/then_and_now_automotive.htm

[desoto1939]

If it were me I would just get a new pump that supports the ethanol fuels.  By the time you buy a kit for around $40 dollars then have to take the old pump apart drive out the pin then rebuild it then drive it the new pin and people have been saying that the pins are sometimes working their way out of the body and then the pump fails then have to take it out again so this is time and money.

 

Go buy a new pump for a little more money have a new unit put it in with a new fuel rubber line and you are good to go.  WHy rebuild if you can just teplace with a fresh unit.

 

This is my two cents. Also if you have a fuel filter on the line to the carb also replace that at the same time.

 

Just did a search on the Parts Geek:  www.partsgeek.com.  Found a 1955 Plymouth Airtex fuel pump for $49.35  plus shipping.  Airtex is a good pump. A kit

will cost the same.

 I just checked the link fromthe prior posting and their kits range from $39.50 to $54.50  and you still have to rebuild the old fp.  So way each cost and do what works best for you.

 

Rich HArtung

desoto1939@aol.com

Edited May 6, 2014 by desoto1939

[ChrisRice]

I bought the airtex. Nice to know the pump can handle ethanol fuel, but my engine won't run on it

Thanks everyone for the help.

[desoto1939]

I bought the airtex. Nice to know the pump can handle ethanol fuel, but my engine won't run on it

Thanks everyone for the help.

What do mean the engine willnot run on it, ethinol?  The fuels that you are getting at the gas sations all now have a blend of ethinol.  I am not saying straight ethinol.  You can get rqacing fuel at some stations up here in PA but you are paying a steep price for it.

 

So what happens when you put fuel in the car. Does it start or not start?  What is the issue.

 

Rich HArtung

Desoto1939@aol.com

[Young Ed]

Chris I'd order a kit and rebuild as a spare. Also as Rich mentioned lots of these have issues with the pin. The majority of the ones with pin issues are the new ones not the self rebuilt ones! So double check it before you install it.

 

Rich around here for colllector cars you can buy ethanol free gas. Its typically .35-.50 more a gallon so I usually don't bother but it is around.

[ChrisRice]

I am running the ethanol free. Yes it's more expensive, but it's what I have to do.

I probably will rebuild to have a backup, it's always nice to have spares. I didn't know that the new ones are problematic, thank you for the heads up.

[ChrisRice]

Rich, it just won't start on ethanol fuels. I don't know why. I've always had to pamper her with the ethanol free.

[hendo0601]

I do believe your leak is coming from the weep hole...which means your fuel pump has suffered an internal leak. This hole is there for just this reason...to leak fuel outside of the engine rather than dump it internally into the crankcase. You need to either rebuild it, replace it, or bypass it with an electric fuel pump. If you go with an electric pump you can leave the mechanical pump in place and just disconnect the fuel lines from the pump and connect the lines together, or you can remove the pump and put a block - off plate in it's place.

[DonaldSmith]

Make sure the block-off plate bolts are not so long as to hit the cam.  If the block-off plate is thinner than the base of the fuel pump, the bolts should be shorter. 

[desoto1939]

if the pump has been rebuilt you had to punch out the pin and then the hole gets alittle iggerI have New Fuel Pumps in my 39 and not rebuilt pumps the pin has not moved. I think the pin moving out of the hole is because the pin is pushed out and the hole get bigger from pushing it out.

 

So if a kit cost 40 dollars and you have to rebuild and then there is the possibilty of the pin issue then just two new pumps and avaoid the hassle.

 

Up here in PA and the Northeast we do not have the option of non ethanol at our stations around the Philadelphia area.. When I spoke to the Airtex Tech rep about the pin issue they have stated that they have not had any reported issues of this type on new pumps. I did this when I was inquiring about the Airtex fp 73201 which is the new replacement for the old AC588 pump which is just a  remanufacture of the old pump with some modifications.

 

Rich HArtung

Desoto1939@aol.com

[Don Coatney]

Rich, it just won't start on ethanol fuels. I don't know why. I've always had to pamper her with the ethanol free.

Most everybody who drives a flathead mopar uses gasoline with corn oil added these days. My car runs on this fuel with no issues. There must be a reason your engine will not run using this fuel.

 

if the pump has been rebuilt you had to punch out the pin and then the hole gets alittle iggerI have New Fuel Pumps in my 39 and not rebuilt pumps the pin has not moved. I think the pin moving out of the hole is because the pin is pushed out and the hole get bigger from pushing it out.

 

So if a kit cost 40 dollars and you have to rebuild and then there is the possibilty of the pin issue then just two new pumps and avaoid the hassle.

 

Up here in PA and the Northeast we do not have the option of non ethanol at our stations around the Philadelphia area.. When I spoke to the Airtex Tech rep about the pin issue they have stated that they have not had any reported issues of this type on new pumps. I did this when I was inquiring about the Airtex fp 73201 which is the new replacement for the old AC588 pump which is just a  remanufacture of the old pump with some modifications.

 

Rich HArtung

Desoto1939@aol.com

As I have stated before the rebuild kit that I bought from antique auto cellar uses a circlip to secure the pin hence no pin falling out issues. However the cost of the kit  was close to the cost of the new pumps you suggested. I would buy a new pump at that cost as opposed to doing a rebuild.

 

[DonaldSmith]

Aw, but what's the fun buying a new one?  How are you going to learn about the innards of the pump?  And you throw the old pump away?  

[desoto1939]

Aw, but what's the fun buying a new one?  How are you going to learn about the innards of the pump?  And you throw the old pump away?  

Don you can always open up the old FP to see how it works and never throw it away. You keep the parts as spares.  What I am trying to say is that if the cost is almost equal to a fresh new pump then why would you go to the expense to order a kit and then rebuild it and then always have to wonder if it was rebuilt correctly.  If the kit cost like 10 dollars then yes rebuild the pump. I prefer to have a fresh new modern pump as a spare instead of a rebuilt pump. that is my preference.

 

Same with water pumps  you can buy a kit for 50-60 dollars  but you can buy a brand new water pump for $50 with all new gaskets and it is ready to install.

 

Just my 25 cents worth.

 

rich Hartung

[DonaldSmith]

All seriousness aside, as Steve Allen used to say.  You make good points.  I suppose I'm not the only one that has a museum of old parts that are just too good to throw away.  

 

In the old days I would tinker with something for a week to save a few bucks.  But now,after a long life of scrimping to get by and fixing everything myself, I am loosening up a bit and buying good, new stuff. 

 

Our family motto, enshrined on a plastic-coated paper plate that has been wiped clean and reused several times:

 

         The

      SMITHS

  we revel in our 

      frugality

[Young Ed]

All seriousness aside, as Steve Allen used to say.  You make good points.  I suppose I'm not the only one that has a museum of old parts that are just too good to throw away.  

 

In the old days I would tinker with something for a week to save a few bucks.  But now,after a long life of scrimping to get by and fixing everything myself, I am loosening up a bit and buying good, new stuff. 

 

 

 

I agree for the most part however I am not convinced that when buying a new one you are getting GOOD new stuff.