Hi all,
This problem is on my '72 Ford F100 with a 360. The pcv valve is in the passenger side valve cover.
Any ideas on why the hose from my pcv valve to the back of the carb is collapsing? I didn't think it was supposed to have that much suction. It's just 3/4 inch heater hose. I did buy some nicer Gates hose rated for gas/oil but from the looks of it while it might not break down so easy it isn't reinforced or anything.
I did buy a new pcv valve and it's the same.
Might this be an indication of something bad? Sure hope not.

thank you

 

Normal heater hose is not rated for oil use . It will fail soon . Get the proper hose and see how it goes .

 

A new thread on the same subject you posted earlier?

https://www.ford-trucks.com/forums/1...-pcv-hose.html

The PCV system is designed to evacuate crankcase gas and introduce it into the intake charge to be burned as part of the combustion cycle. There are two designs - open and closed.

An open system on these rigs draws fresh air from the driver side valve cover through a twist-on or push-in breather. A close system is the same except that the driver side breather has a hose connected to the air filter housing - either to a fitting under the housing on the clean side of the air filter or a fibrous filter clipped to the housing.

Still collapsing eh.. Hmmmmm. Well, what system do you have? Open or closed? Post a pic if you can... let's see how your system is set up.

Here's an illustration for a Bumpside::

 

Hi,

Yes, I posted again as I really didn't get an answer about the collapsing.

My system is closed. The Oil Cap in the drivers side valve cover attaches to the air cleaner, and the pcv valve is in the passenger side.

Now the wierd thing is that there is another small tube coming off the air cleaner with nothing attached. It's on the passenger side but towards the front of the motor.

The current hose I have is brand new so the oil and gas haven't had a chance to degrade it yet. It is rather large on the pcv side because the carb side needs to be 3/4 to fit.

Any and all help/ideas are appreciated.

 

Try this.... with the engine running observe the PCV's hose that it is collapsed. Then remove the oil cap on the driver's side. Does the PCV's hose return to normal size?

Report your results.

You've piqued by curiosity. Please post a pic of the air cleaner housing... especially the "extra" tube. To the best of your knowledge, is the air cleaner housing correct for a Bumpside?

 

Ok,

So I went outside started her up. Took the oil cap, drivers side off and it had no affect on the collapsing hose on the other side. Tried it a couple of times.
Took photos. Sorry, I have not figured out how to post them here, but I was able to post them to my Garage. Should just be under my name Binkowski. Took one of passenger side, one of drivers side and one from overhead. Passenger side clearly shows "extra" unattached tube.
Beginning to wonder if things just aren't connected in the right order on each side. Curious to know what you all say.

Thank you.

 

That is Clearly not the proper hose for the application .

 

Thanks for the pics.

I think the main issue is yes, the incorrect hose. See, when the hose has to deform in order to connect the PCV to the carb base, it is already "crimped". The vacuum from the carb base doesn't have to be all that high to further suck it closed because of the deformity. It is more difficult to collapse a round hose than one that is oval.

Do you still have the old hose? Ya might try bending up some tube and use the hose's ends as slip-fit connectors.

I believe the other fitting/nipple/hose connection is for a tube from the charcoal canister to suck out fuel tank vapors. I'm not sure if 72s were equipped with them. If not, then plug the fitting.

 

I will try a new hose. This all started when I purchased the truck a few weeks ago. Just going through everything and I noticed that the hose on the pcv to carb was just heater hose. I figured because it wasn't rated for oil/gas that it was collapsing because it was degraded. Ended up with a 3/4 inch hose so it fits the carb side and it's just crimped down to 3/8 on the pcv valve side. I have some Gates hose but it's 3/4 too. Suppose I could step it down with some fittings but that seems kinda silly.

I'll search through my catalogs but I think Dennis Carpenter has a hose. Just thought I could make it work instead of a fancy $8 hose. The parts stores don't carry it.

Interesting enough the '72's do have canisters for the fuel vapors from the tank. I have them. They are down low on the frame in the front passenger corner, so it's in line with where that "extra fitting" is. There are two connected cannisters and one is connected to a line to the fuel tank behind the seat and the front one is just open. That would explain where it should be fitted to.

Will update when I have a chance to try the proper hose.

Always open to more ideas.

Thanks.

 

NAPA carries the vent tube for the evap can. It's a 3/4-inch corrugated aluminum hose about 36 inches long. Sorry I have not a part number.

 

Hey there I had the same problem with the hose collapsing,heater hose is the wrong type of hose, because when it heats up it gets soft and the walls are not thick enough, thats why it collapses with the suction created by the vacuum, pcv hose has a thicker wall that won't allow it to collapse, go to the napa auto parts and ask for pcv vacuum hose that is where I got mine hope this helps

 

Heater hose is not used with emission parts, oil fumes will cause it to become soft, will eventually collapse. Neoprene hose used instead.

1968/72 F100/350 V8's: Smog valve fits into rubber grommet in right (passenger) side valve cover, hose routes from smog valve to nipple on carb spacer plate.

Oil cap in left (drivers) side valve cover has a hole in its center for rubber grommet. 45 degree plastic elbow fits into grommet, hose routes from elbow to air cleaner nipple.

C7TZ-6A664-B (replaced C7TZ-6A664-A) .. Neoprene PCV Hose / 5/8" I.D. valve end & 1/2" I.D. tube end / Obsolete

1967 F100/350 352 from CHG/L9 / 1971/72 F100/350 360/390.

GREEN SALES CO. in Cincinnati OH has 2 = 800-543-4959.

NOS PARTS LTD in Waxahachie TX has 7 = 972-937-2201.

CARPENTER NOS OBSOLETE PARTS in Concord NC has 2,028 (!) = 800-476-9653.
Evaporative Emission System (Evap/Em) introduced in 1970, was mandatory initially in sold new in CA Passenger Cars, F100's, Bronco's and Econolines.

It was probably mandatory in other states as well. By the end of the decade, most 50 state/Canada F100/350's have Evap/Em.

Left: Note 9D667 hose routing from canister to air cleaner.

The aluminum flexible hose that HIO is referring to...is the auto parts store replacement for D4ZZ-9D667-B .. Black Corrugated Paper Hose-55" long.

 

Hi all,

Thank you HIO Silver and Bill for the awesome information.

Once again, it doesn't pay to cut corners sometimes. I'll get on getting the correct hoses and will report back what happens next...

Thanks.

 

I have the typical setup for a 352. PCV valve off of the right side into the back of the carb spacer. The nipple broke off and now I'm screwed. I can't find a replacement spacer anywhere. There is a capped port behind the carb on the right side labeled "DIF" going straight into the manifold. Could I route the PVC into there? Then I can just use a closed 2 bbl spacer and be set. Is that right? Any help would be great, thank you!!

 

Welcome to FTE!
The spacer's part number was C5TZ9A589C. I don't see anybody showing it either. If that port you mentioned goes to intake vacuum then yes, you can use it. BTW, just so you know, it's better to start your own thread. And we are 67-72 Bumpsides here.