What's this rubber hose for ?

LandShark68_2+2 · Guru

What's this rubber hose for ?

seventy2plus2 · Canadian Poncho Superstar!

One end goes to the carb, the other end onto the small valve on the underside of the air cleaner housing. Then another hose goes onto the other port of the valve, to the flapper on the air cleaner snorkel.

4SPEED427 · A Poncho Legend!

Yes, it should control the valve in the air cleaner so you pull warm air off the exhaust manifold into the air cleaner until the engine warms up.

LandShark68_2+2 · Guru

For the life of me, I can't find where this rubber hose attaches to the carb.
Here are a couple more pictures with the breather lifted off the carb and set back.
I don't see anywhere where this rubber hose would attach.

Regards, Scott (LandShark ...)

LandShark68_2+2 wrote:
Hi guys,
I recently installed a new carb on the 68 2+2 and I am wondering what this rubber hose is for, coming out of the bottom of the breather.
Does it attach to the carb somewhere or does it just dangle ?

Regards, Scott (LandShark ...)

Cheviac · Guru

It slips on to the pipe on the passenger side that has a rubber cap on it now.

seventy2plus2 · Canadian Poncho Superstar!

Cheviac wrote:
It slips on to the pipe on the passenger side that has a rubber cap on it now.

yup.

cdnpont · Canadian Poncho Superstar!

Any excuse to show some shots of that great 396 eh Scott?

LandShark68_2+2 · Guru

Cheviac wrote:
It slips on to the pipe on the passenger side that has a rubber cap on it now.

Thanks guys,

I think I know now why that rubber hose was never attached to vacuum on the carb. The flapper closes when it should be open.
Easy solution was to just pull the hose off.

For now I'm going to leave it dangling, or as a carb guy told me today, just plug the hose with something and then put it on the carb, that way
it looks right but will not activate the flapper.

Regards, Scott (LandShark ...)

67Poncho · Uber Guru

AND, could you please, please please, remove that fuel filter from there, replace that complete section of steel line with rubber hose and fuel filter from the fuel pump outlet to the carb inlet with the proper 1 piece steel line? If you want a filter, add it before the fuel pump, most commonly at the fuel tank so to trap dirt before it travels to and through the pump.

If any of those clamps fail or the rubber hose pops, the pump will feed fuel till the tank runs dry or will feed the unmentionable flames. NEVER add a filter after the pump near the carb with a rubber hose. Also the heat from the engine with those that add a plastic filter.... ((CRINGE))

If the hose or clamps were to fail on the inlet side of the pump? The carb runs out of fuel, engine quits and no harm, no foul from spraying fuel... (hopefully no one runs into you from behind)

I replaced that exact pipe on my Estate wagon for that reason... Someone twisted the pipe, cut it and placed a hose there. CHEVIAC? Hahahahahaha..... :)

Just my 2 pennies.

-- Edited by 67Poncho on Sunday 17th of July 2022 04:38:20 PM

seventy2plus2 · Canadian Poncho Superstar!

LandShark68_2+2 wrote:
Cheviac wrote:
It slips on to the pipe on the passenger side that has a rubber cap on it now.

Thanks guys,
I think I know now why that rubber hose was never attached to vacuum on the carb. The flapper closes when it should be open.
Easy solution was to just pull the hose off.
For now I'm going to leave it dangling, or as a carb guy told me today, just plug the hose with something and then put it on the carb, that way
it looks right but will not activate the flapper.
Regards, Scott (LandShark ...)

The vacuum valve on the bottom of the air cleaner housing is temperature sensitive. It operates the flapper, and provides pre-heated air from the heat stove when the engine is cold. When the engine warms up, the flapper allows cooler air to come from the snorkel. They're color coded, I presume it should be the black one like in my 1970's. I should have a spare around if you want a replacement.

Prefectca · Poncho Master!

67Poncho wrote:
If any of those clamps fail or the rubber hose pops, the pump will feed fuel till the tank runs dry or will feed the unmentionable flames. NEVER add a filter after the pump near the carb with a rubber hose. Also the heat from the engine with those that add a plastic filter.... ((CRINGE))
Just my 2 pennies.

I can tell that you havent owned a Ford. Just about every Ford with a carburetor had the fuel filter screwed into the carb with a short hose and two clamps. Yes they caught fire, a rubber fuel line beside the distributor, what could go wrong?
I agree with you about the rubber hose possibly leaking but Chrysler cars also had rubber lines on the fuel filter.

Paul

LT1Caddy · Poncho Master!

67Poncho wrote:
AND, could you please, please please, remove that fuel filter from there, replace that complete section of steel line with rubber hose and fuel filter from the fuel pump outlet to the carb inlet with the proper 1 piece steel line? If you want a filter, add it before the fuel pump, most commonly at the fuel tank so to trap dirt before it travels to and through the pump.
If any of those clamps fail or the rubber hose pops, the pump will feed fuel till the tank runs dry or will feed the unmentionable flames. NEVER add a filter after the pump near the carb with a rubber hose. Also the heat from the engine with those that add a plastic filter.... ((CRINGE))
If the hose or clamps were to fail on the inlet side of the pump? The carb runs out of fuel, engine quits and no harm, no foul from spraying fuel... (hopefully no one runs into you from behind)

I replaced that exact pipe on my Estate wagon for that reason... Someone twisted the pipe, cut it and placed a hose there. CHEVIAC? Hahahahahaha..... :)
Just my 2 pennies.

Boy...You are sensitive. I can't count the cars that had filters after the pump. Some were even plastic... I have even seen RACE engines with the "NEVER" add problem. Most of them didn't burn down... They usually quit running when the carb has no fuel...and stop pumping gas. The quality of the install is most important.....
Just my.02 cents

-- Edited by 67Poncho on Sunday 17th of July 2022 04:38:20 PM

67Poncho · Uber Guru

LT1Caddy wrote:
Boy...You are sensitive. I can't count the cars that had filters after the pump. Some were even plastic... I have even seen RACE engines with the "NEVER" add problem. Most of them didn't burn down... They usually quit running when the carb has no fuel...and stop pumping gas. The quality of the install is most important.....
Just my.02 cents

Absolutely.... most things could/can be preventable but we sometimes take the risk. Most and usually are 2 words that are always considered as 100%? It was just a suggestion and a suggestion only. He/she/they/anyone can/may decide for themselves.

Again, $.02

67Poncho · Uber Guru

Prefectca wrote:
I can tell that you havent owned a Ford. Just about every Ford with a carburetor had the fuel filter screwed into the carb with a short hose and two clamps. Yes they caught fire, a rubber fuel line beside the distributor, what could go wrong?
I agree with you about the rubber hose possibly leaking but Chrysler cars also had rubber lines on the fuel filter.

Paul

I know what you are saying. In all honesty, I would rather say something and to be somewhat criticized versus not say anything at all and have something happen that could have been prevented. I know it isn't my car but I can still suggest.....

And no.... no Fords or Dodges ever.

-- Edited by 67Poncho on Monday 18th of July 2022 12:37:04 AM

Prefectca · Poncho Master!

Also when installing an aftermarket inline fuel filter the installation instructions usually specified that the filter should be after the fuel pump. The reasoning was that fuel pumps usually push better than they pull and the added restriction from a filter before the pump could affect pump operation and starve the engine for fuel.

Paul

DonSSDD · Canadian Poncho Superstar!

Then there are the glass bowls after the fuel pump from the factory. I even have an old Pioneer chainsaw that has a glass bowl.

67Poncho · Uber Guru

DonSSDD wrote:
Then there are the glass bowls after the fuel pump from the factory. I even have an old Pioneer chainsaw that has a glass bowl.

Yes Sir! Very familiar. I added the water separator to my '51 1430 shortly after I bought it in '99. The fuel pump had the glass sight originally. BUT, it is attached with the proper fitting to the carb and the original double flared fuel line. The fuel filter is under the cab where the line exits the tank.

I guess, in a final epitaph, if you wish to add a fuel filter in line between the fuel pump and the carb, not done from GM in this manner, try to add a barb to the line like the fuel filter ends, instead of leaving the line smooth where it was cut. Out.

-- Edited by 67Poncho on Tuesday 19th of July 2022 09:55:55 AM

MC · Canadian Poncho Superstar!

67Poncho wrote:
Prefectca wrote:
I can tell that you havent owned a Ford. Just about every Ford with a carburetor had the fuel filter screwed into the carb with a short hose and two clamps. Yes they caught fire, a rubber fuel line beside the distributor, what could go wrong?
I agree with you about the rubber hose possibly leaking but Chrysler cars also had rubber lines on the fuel filter.

Paul
I know what you are saying. In all honesty, I would rather say something and to be somewhat criticized versus not say anything at all and have something happen that could have been prevented. I know it isn't my car but I can still suggest.....
And no.... no Fords or Dodges ever.

-- Edited by 67Poncho on Monday 18th of July 2022 12:37:04 AM

Can't speak about Fords, because I think I've only ever had about 2 carbureted Fords.

Can't really speak about GM, as I haven't owned a GM in many years (almost did a few years ago, until the sleazebag selling the car sold it for a few bucks more while I was on the way to hand him a cheque for the agreed price). Gotta love the old car hobby.

I will say that Chrysler Corp vehicles used the inline fuel filter after the pump for many years and I have never had an issue with them. Nor has anybody I've known (and I know a lot of Mopar guys). Always used the metal filters and always installed new hoses with each filter. The lines before and after the filter were always swaged or flared (or whatever you call it), to ensure that the clamped hose wouldn't slip off, and to be honest after the hose had been on the pipe for awhile, some adhesion would occur to the point where it was difficult to remove the hose from the pipe. Anyhow, not to drag it out, but it seems like the Chrysler engineers knew what they were doing...

Canadian Poncho · A Poncho Legend!

I think it's expected owners (or their mechanic) will check those hoses during regular maintenance. The issue is if you never check the rubber portion of the fuel line it and it gets old and splits (which I've seen).

MC · Canadian Poncho Superstar!

Sure, if nobody looks at it for 10 or 15 years. That holds true for other critical rubber items, like brake flex hoses (especially critical when keeping a single chamber master cylinder system).

FWIW, I think Vince is right on with his thinking - safety first, and if there's a better way of doing it that will avoid disaster, then it should be done that way.

I do, however, push back at the notion that GM is superior in all aspects, and that other manufacturers' engineers didn't know what they were doing, etc., blah blah blah. I know this is a GM board, but somebody has to say it, or you're stuck in a boring echo chamber... wink