Mechanical fuel pump leaks

[Astrowing]

By design, I think if a diaphram on a fuel pump fails, that the leaking fuel should spill externally through the vent holes of the pump. Is there anything to look for that would cause fuel to go into the crankcase instead? Or is it not surprising that you'll get fuel in the oil when a pump fails in any case?

[jopizz]

I've had far too many old cars with gas in the oil to think it's a coincidence. It must be common for fuel pumps to leak through the shaft opening into the crankcase.

[Joe Johnston]

Depending on the cause or location of the leak, there is nothing to stop the gas from entering the engine through the hole in the side of the block where the pump arm goes through. Old school mechanics would always feel and smell the oil on the dipstick when checking the oil even though such a failure is rare but does happen.

I "think"* the supercharged Y-Block engines had a gasket or bellows type of seal that went around their modified fuel pump's arm but no others that I am aware of.

*(getin old and don't remember everything like I used to!)

[Guest]

Hey Guys,
You may think I'm crazy Went with a friend of mine several years ago to look at a small truck. The dealer had the truck backed up a small hill. I was checking things out and we raised the hood. For some reason I pulled the dip stick to check the oil. It showed it was right at full. I thought thats odd. So I felt of the oil and it just did not feel right. I smelled the oil and it did not smell right. I tasted the oil and could taste gas in the oil We told the dealer. He chased it down to a bad mechanical fuel pump! I told my friend I would be leery about buying the truck, because you don't know how long its been ran that way!
My opinion and comments are not the opinion and comments of Squarebirds.org! Do not try this at home
Richard D. Hord

[lawyercalif]

My 59 had that problem when I bought her. Lots of gas in the oil. I put in a new fuel pump, but I think the damage was done already since the strong running engine has a slight knock at anything over 2500 rpm or under load. That is why I am putting in the 390.

[Guest]

Had to put bearings in a 76 LTD 400 because of a bad fuel pump. It had 21000 miles on it. Made me sick

[JohnG]

You guys all make a case for either having an electric pump, or a mechanical pump rebuilt with materials compatible with today's gasoline. Too much risk involved!

Richard: there is an old Cheech and Chong story that parallels yours but is not about gasoline that I should tell you by email sometime . . . believe it was about a dogsled team in Russia.

John

[simplyconnected]

You guys all make a case for either having an electric pump, or a mechanical pump rebuilt with materials compatible with today's gasoline. Too much risk involved!...

Hmmm... 30 dollar fuel pump or $6,000 overhaul... I just can't decide...

John, I'm in favor of the electric pump. All modern cars have one so we're used to their dependability by now. No such thing as a 'dry' fuel system, cranking forever, trying to get gas up to the carb. It happens as soon as the key is turned. But a word of caution to all: If you go with an electric pump, also install the inertia switch. All our modern cars have one, in case of an accident they shut off power to the pump. RESET, is that little white button usually located in your trunk. Junk yards crush these switches daily because nobody ever buys replacements.

[JohnG]

similar comments hold with regard to some contemporary cars and intake manifolds. If you lose the ability to seal the coolant, it goes into the motor and oil and you soon ruin your bearings. This happened to one manufacturer in two areas: intake manifold gasket, and plenum.

Ya gotta protect that motor!!

John

[Jimz Bird]

A couple of options for fuel shut off on electric pumps that could be considered.

http://www.amazon.com/Holley-12-810-Electric-Safety-Pressure/dp/B00029JC7G/ref=sr_1_1?ie=UTF8&qid=1330901273&sr=8-1

http://www.napaonline.com/Catalog/Result.aspx?Ntt=ECH+OP6610&Ntk=Keyword&Nty=1&Dn=0&D=ECH+OP6610&Dk=1&Dp=3&N=0

And a simple wiring diagram.

It would seem that the Oil Pressure cut off switch would be easier to ops check.

[JohnG]

Jim - thanks! Good job!!!

John

[Astrowing]

If you add an electric fuel pump, you need to remove the old mechanical one. If you leave the old one in place, the failure mode that puts gas in the oil is still there. I wouldn't want anyone to be thinking that they've converted to electric and therefore don't have to be as vigilant checking oil level and for the presence of gas.

I'm hearing that Y-blocks and the FE's use the same fuel pump, and you would think they would still be manufactured since they were used until about 1976 in trucks. I think the problem with the 223 pumps in particular, is that they are NOS meaning the rubber may be really old and they've sat on the shelf for years. And were manufactured well before anyone ever dreamed of ethanol in gas. Does anyone know material-wise what they are changing to be more compatible with ethanol? What should one look for in a rebuild kit?

[Jimz Bird]

I'm hearing that Y-blocks and the FE's use the same fuel pump, and you would think they would still be manufactured since they were used until about 1976 in trucks.

Dave D will know for sure if they will work but the part#'s are different at RockAuto and they do have them.

The Ford Parts Interchange lists separate part #'s for 55-57, 58, 59. For the 60 it lists the same one for without vacuum assist for Ford 60-62 292,352 - Edsel 60 292,352 - Mercury 61-62 292, 352,390 and Tbird 60-62 352,390.

So I am a bit confused - Dave will know.

[Joe Johnston]

While the main part of the pump may be "alike" some models had a glass filter bowl, others (little Birds) were the dual action for vacuum assist, and still others may have the bottom "clocked" in a different orientation. All may be the same basic pump with exterior differences and therefor a different part number.

Dave - straighten us out!

[simplyconnected]

Joe hit the nail on the head. It's like asking if windows fit a house. There are so many variations of the same size it isn't funny. Some FE's need vacuum for their wipers, others have electric wipers. Some use the metal screw-off filter can, others don't. Most (including Y-Blocks) simply have an arm that rides on the cam eccentric 3" to 4-1/2" from the timing cover face.

it makes no sense to crank a whole engine just to work that little lever up and down, after the car sits for a month. And John G is right about jeopardizing your engine for a minor gas leak.

My suggestion is also to go with an electric pump and cover the opening with a plate and a gasket. The main idea is to deliver gas BEFORE the engine cranks, and electric pumps do that nicely. There has been concern over too much pressure coming from the pump. My auto parts store carries a low-pressure regulator because your carb only needs a few pounds at the inlet (not 10-30). Modern pumps do modern fuel very well.

I would put the pump as close to the tank as possible (to keep the suction side short) but not in the trunk (just in case). There is plenty of room above the axle, in free air, safely away from any enclosed space. I would also filter AFTER the pump, at the engine, using a modern large metal filter (as someone mentioned). I look at the filters for Mustangs, Crown Vic's, etc., and they are just fine. It is nice to see through plastic, but Ford filters are all metal for good reasons.

I use plastic vinyl tubing as a 'test' to see my fuel flowing as I watch for bubbles or debris. Then, I promptly replace with real line. BTW, when fuel is under positive pressure, there is no such thing as, cavitation or 'vapor lock', not even in elevation.

The relay circuit is ok but, I'd still rather use the mechanical pendulum switch commonly found on most all cars and trucks. The pendulum switch works differently, shutting off the fuel upon any abrupt hit from any direction. Otherwise, it is on all the time. There are only two wires that connect to the pump in series. The pendulum switch can be in the trunk because there are no vapors, just electric wires. You can also use this circuit for security. No fuel means no engine running, no matter how long it cranks. Endless possibilities, here. Hope this helps. - Dave