I recently had a road draft tube act as if it were leaking out the tube, Cleaned and painted it, new filter and checked surfaces for mating, used some Hylomar on gasket surfaces. Still leaking, I knew my engine was ok because it never leaked a drop and all of a sudden was leaking out the draft tube quite heavy when run hard.

I jacked the car up and I laid down under the car with the motor running wiping the tube clean with a rag and found it was coming from the back side of the tube. I traced the leak and found a tiny pinhole in the canister about a quarter inch from the tube between the motor and tube. This is right where the oil should be flowing back into the engine and it is also the low point in the canister which is where condensation would settle and rust it out. There was a tiny spot on the newly painted canister where the paint had peeled off and in the middle of that spot was a tiny pinhole that would create a drop about every 30 seconds or so. This drop would form a small stream and flow down the back side of the tube and around the tapered edge so it looked like the oil was coming from inside the tube.

Something to keep in mind when dealing with a leaky draft tube is that it may be coming from outside the tube due to condensation corrosion around the tube or canister.

Although I had it off 2 times for cleaning and painting I never discovered it so if you take it off, pick around the bottom of the canister with an awl. It was a relief finding the real problem, thats an easy fix, motor problems aren't.

55 Vicky & customline

58 Rack Dump, 55 F350 yard truck, 57 F100

59 & 61 P 400's, 58 F100 custom cab, 69 F100, 79 F150, 82 F600 ramp truck, 90 mustang conv 7 up, 94 Mustang, Should I continue?

Thanks, that's something worth looking into and makes a lot of sense.

Hello Ron,I just converted my 56 to PCV system and I have to say its a vast improvement over the road draft setup.When I walk in the garage it doesn't smell like oil and gas.I don't have puffs of smoke comming from under the motor when I stop at a light.For whats involved in converting its well worth it in my opinion.Regards,Mark

  

I wanted to clean out the filter on the road draft tube of my '56 312, as I was getting quite a bit of exhaust out of the filler tube. I replaced all the gaskets in the engine a few years back, but for some reason I was too intimidated by the odd device to even mess with it. Now that I finally opened it up, you should have seen the pile of gunk stuck in there! The old oil came out of the can like a jello mold. When I got it all cleaned up, I noticed the cover seemed to press quite hard onto the filter, but because I hadn't read this post yet I thought, Oh well, all the better to seal it up!

It only took a few fast corners after it was all assembled to find that something was clearly not right. Oil was everywhere! I searched the forums for answers (why don't I do that ahead of times one in a while??) and found that the filter should be trimmed down. With some patience and a pair of wire cutters I had it fitting nicely.

However, I noticed that no matter how I spun the cover of the breather, I could not get the hole for the bolt to line up right with the tab that the bolt screws into. Just like Aussie Bill said in a previous post, I had to bend the tab a bit until the cover would sit even on the gasket.

Now that its all put together right I've been burning around corners and working the engine HARD. So far I've seen one drip come out of the tube onto the pavement. A VAST improvement! Thanks again everyone for your help! Wanted to be another witness that you may need to bend your tab back into shape to get the cover to sit properly.



Ced

can someone pls post pics or a site/search that will show parts being described

both my 292s are fresh rebuilds and would like to have this resolved before install

they both have tubes that screw into the block through the valley pan and simply vent down and over bellhousing with no restriction, no filter, nothing.

my 80 year old engine rebuilder did give me a piece that will srew into the valley pan but has a smaller tube nipple, i assume to vent back through a pcv valve, like the 223 6 cyl does,back into the intake...

thanks for your help

john

Unibody; Since your engines aren't installed, you might want to convert to a PVC setup. There are several posts on that subject going back.

Ced; The other thing to remember with the crankcase venting, is to remember that the air intake on stock engines is thru the oil filler cap. Ensure that the screen is kept clean, or the system doesn't work.

Paul

Guess I'm lucky my car was sold in California and they required a PCV. So my car came with the oil cap venting to the air filter and the PCV going to a plate mounted under the carb. The vent on the left side of the block has a cap bolted in its place.

Ol'ford nutCentral Iowa

56 Vic w/292 & 4 spd.

Just in case anyone comes across this old post...I found why my draft tube was leaking, is was loose from the block and oil was running down the OUTSIDE of tube, only looked like is was from inside tube

Where does the draft tube return to on the block what side? Someone put a PCV valve on mine screwed it into the manifold and ran a hose from that to the canister on the back of the motor which I am assuming is the Road draft tube canister... And I am thinking that this is the cause for my Vacume leak symptoms irratic idle...

In case you don't catch my other post,the PCV screwed into the intake in front of the carb is the original factory equipment on a 64 truck.

 

Paul,

Boonville,MO