1955 Oil Leak | Ford Thunderbird club group 1955-2005 T-Bird models

  • We're glad you found us via a search engine! Right now, you can join our club absolutely free and unlock member only features like the site search! This notice only appears once! It only takes 30 seconds to register, and we would love to have you as part of the World's largest Thunderbird Forum/Club! Click here to continue

1955 Oil Leak

  • Thread starter Thread starter lbc3
  • Start date Start date
lbc3

lbc3

Bronze Member
Reaction score
5
Thunderbird Year
1955
Post does not meet subject criteria
I am trying to identify the source of an upper engine oil leak. It seems to be emanating from around a gasket between the pictured black tube and the valley pan (if that's what it is called). I have a National Parts Depot catalog but can not identify that tube and or the gasket. Perhaps someone here knows what it is and if it could be the leak source based on it's function? Thanks, Peteoil leak 5 .jpegoil leak 6 .jpeg

This page contains affiliate links for which I may be compensated. As an eBay Partner, and Amazon Associate I may be compensated if you make a purchase at no cost to you.

 
Last edited by a moderator:
That is the crankcase down draft vent tube. It ventilates the crankcase as these cars were made before the advent of the PCV Valve (positive crankcase ventilation). It expels the vapors and un-burned oil and gas from your crankcase out the bottom of the car and makes a mess and smells bad. I changed mine out with the PCV valve adapter. Very easy to do. Also car runs better and smells better and no drips from the bottom of the tube anymore.
www.classictbird.com

PCV Conversion Kit - 57 2bbl - 1 Per car-classictbird.com

PCV conversion kits includes gaskets. PCV valve in kit is metal, replacement is plastic. Spacer is made from 1/2 thick aluminum
www.classictbird.com
 

Attachments

  • 6758C.jpg
    6758C.jpg
    35.7 KB · Views: 5
The black pipe is called the ‘draft tube’. Air passing under the car sucks out crankcase fumes. The oil leak is more likely from a failed cork valley pan gasket (common because over-tightening distorts the pan). Cure involves removing the intake manifold & straightening the pan somewhat. Thicker neoprene gaskets are available (if reuse is desired), and should be glued to the pan with black ATV. If it still leaks, then more ATV on the block side will usually stop it, even with cork.
 
JimLeanna55Bird said:
That is the crankcase down draft vent tube. It ventilates the crankcase as these cars were made before the advent of the PCV Valve (positive crankcase ventilation). It expels the vapors and un-burned oil and gas from your crankcase out the bottom of the car and makes a mess and smells bad. I changed mine out with the PCV valve adapter. Very easy to do. Also car runs better and smells better and no drips from the bottom of the tube anymore.
www.classictbird.com

PCV Conversion Kit - 57 2bbl - 1 Per car-classictbird.com

PCV conversion kits includes gaskets. PCV valve in kit is metal, replacement is plastic. Spacer is made from 1/2 thick aluminum
www.classictbird.com
Click to expand...
Thank, Jim. Makes sense. When you say "makes a mess", does that mean it could possibly be the source of the visible oil accumulation? Even so, it seems like a good modification so I will peruse the installation information on the site you referenced to see if I can manage it. Thanks again, Pete
 
lbc3 said:
Thank, Jim. Makes sense. When you say "makes a mess", does that mean it could possibly be the source of the visible oil accumulation? Even so, it seems like a good modification so I will peruse the installation information on the site you referenced to see if I can manage it. Thanks again, Pete
Click to expand...
Where do you see oil
Leaking? If it is just on the ground under car it could be dripping out of the vent tube! Mine had oil around the interface with the vent tube snd valley pan. Once I installed the PCV valve that oil accumulation went away because it actually now sucks it out of that area into the carburetor to re-burn.
 
DynoDan55 said:
The black pipe is called the ‘draft tube’. Air passing under the car sucks out crankcase fumes. The oil leak is more likely from a failed cork valley pan gasket (common because over-tightening distorts the pan). Cure involves removing the intake manifold & straightening the pan somewhat. Thicker neoprene gaskets are available (if reuse is desired), and should be glued to the pan with black ATV. If it still leaks, then more ATV on the block side will usually stop it, even with cork.
Click to expand...
I prefer to use weather strip adhesive to hold the lifter valley cover in place and seal it because there are no slots or dowels to hold the gasket in place during assembly. The lifter valley cover is held in place by two bolts and grommets. Do not overtighten the bolts; doing so bends the cover and creates oil leaks around the cover. The torque is listed in the manual as "Valve Pushrod Chamber Cover" and the torque value is 12-15 inch pounds. I torque mine to 20-inch pounds with perfect results. I torque the draft tube to 20-inch pounds as well.

doug7740
1955 Thunderbird Blue
 
DynoDan55 said:
The black pipe is called the ‘draft tube’. Air passing under the car sucks out crankcase fumes. The oil leak is more likely from a failed cork valley pan gasket (common because over-tightening distorts the pan). Cure involves removing the intake manifold & straightening the pan somewhat. Thicker neoprene gaskets are available (if reuse is desired), and should be glued to the pan with black ATV. If it still leaks, then more ATV on the block side will usually stop it, even with cork.
Click to expand...
DynoDan55 said:
The black pipe is called the ‘draft tube’. Air passing under the car sucks out crankcase fumes. The oil leak is more likely from a failed cork valley pan gasket (common because over-tightening distorts the pan). Cure involves removing the intake manifold & straightening the pan somewhat. Thicker neoprene gaskets are available (if reuse is desired), and should be glued to the pan with black ATV. If it still leaks, then more ATV on the block side will usually stop it, eve
Click to expand...
DynoDan55 said:
The black pipe is called the ‘draft tube’. Air passing under the car sucks out crankcase fumes. The oil leak is more likely from a failed cork valley pan gasket (common because over-tightening distorts the pan). Cure involves removing the intake manifold & straightening the pan somewhat. Thicker neoprene gaskets are available (if reuse is desired), and should be glued to the pan with black ATV. If it still leaks, then more ATV on the block side will usually stop it, even with cork.
Click to expand...
I fear you are right. I am searching YouTube for a "how to" for that. Seems to be a lot of concern for distorted covers. Is it your opinion that neoprene gaskets are superior? The reference I found mentioned them as
DynoDan55 said:
The black pipe is called the ‘draft tube’. Air passing under the car sucks out crankcase fumes. The oil leak is more likely from a failed cork valley pan gasket (common because over-tightening distorts the pan). Cure involves removing the intake manifold & straightening the pan somewhat. Thicker neoprene gaskets are available (if reuse is desired), and should be glued to the pan with black ATV. If it still leaks, then more ATV on the block side will usually stop it, even with cork.
Click to expand...

JimLeanna55Bird said:
Where do you see oil
Leaking? If it is just on the ground under car it could be dripping out of the vent tube! Mine had oil around the interface witC1AE 6A665-G I h the vent tube snd valley pan. Once I installed the PCV valve that oil accumulation went away because it actually now sucks it out of that area into the carburetor to re-burn.
Click to expand...
The pooled oil is visible around the tube where it connects to the cover and around the cover itself. It is a significant amount, so I fear it is the valley cover gasket . I did find a suggestion using a "teapot" adapter that replaces the draft tube and routes the crankcase fumes to the carb via rubber hose, assuming the carb has a port that will accept it. I have no idea what kind of carb I have and so far have been unable to locate that "teapot" part.
 
If I assume mine leaks do to over tightening, must I replace the valley cover, or will a neoprene gasket and gasket sealer correct the distortion? I am hopeful that the gasket was misaligned based on your description of the difficulty in placing it. But first I must find a tutorial on how to remove the manifold, etc. in order to access it. Thanks for your input, Pete
 
lbc3 said:
I fear you are right. I am searching YouTube for a "how to" for that. Seems to be a lot of concern for distorted covers. Is it your opinion that neoprene gaskets are superior? The reference I found mentioned them as



The pooled oil is visible around the tube where it connects to the cover and around the cover itself. It is a significant amount, so I fear it is the valley cover gasket . I did find a suggestion using a "teapot" adapter that replaces the draft tube and routes the crankcase fumes to the carb via rubber hose, assuming the carb has a port that will accept it. I have no idea what kind of carb I have and so far have been unable to locate that "teapot" part.
Click to expand...
lbc3 said:
I fear you are right. I am searching YouTube for a "how to" for that. Seems to be a lot of concern for distorted covers. Is it your opinion that neoprene gaskets are superior? The reference I found mentioned them as



The pooled oil is visible around the tube where it connects to the cover and around the cover itself. It is a significant amount, so I fear it is the valley cover gasket . I did find a suggestion using a "teapot" adapter that replaces the draft tube and routes the crankcase fumes to the carb via rubber hose, assuming the carb has a port that will accept it. I have no idea what kind of carb I have and so far have been unable to locate that "teapot" part.
Click to expand...
Mine did the same thing. Once I installed the PCV valve it stopped. It was not the valley pan cover just oil soaked fumes concentrating in that spot from the down draft tube. The tube just sits in that hole and does not have any type of gasket or grommet to seal it. The PCV conversion kit comes with a plate that installs under the carb and has the vent tube installed in it. Very simple to do. The "teapot" is the carburetor. Mine is a "teapot" carb and you can tell by looking at it (see photos). They were the original carbs on the 55's. The instructions that come with the adapter kit are very straight forward. Once I installed this the oil residue went away and car runs great. You might need to have the air/fuel mixture slightly adjusted because the car will be running a little richer because it will be burning the crankcase fumes.
 

Attachments

  • IMG_5433.jpg
    IMG_5433.jpg
    1.1 MB · Views: 20
  • IMG_5436.jpg
    IMG_5436.jpg
    753.5 KB · Views: 20
  • IMG_5435.jpg
    IMG_5435.jpg
    953.4 KB · Views: 20
  • IMG_5434.jpg
    IMG_5434.jpg
    720.5 KB · Views: 20
  • 6758AA.pdf
    6758AA.pdf
    19.3 KB · Views: 7
Last edited:
doug7740 said:
I prefer to use weather strip adhesive to hold the lifter valley cover in place and seal it because there are no slots or dowels to hold the gasket in place during assembly. The lifter valley cover is held in place by two bolts and grommets. Do not overtighten the bolts; doing so bends the cover and creates oil leaks around the cover. The torque is listed in the manual as "Valve Pushrod Chamber Cover" and the torque value is 12-15 inch pounds. I torque mine to 20-inch pounds with perfect results. I torque the draft tube to 20-inch pounds as well.

doug7740
1955 Thunderbird Blue
Click to expand...
The problem with WS adhesive is it isn’t oil-resistant. Actually, red ATV with no gasket would likely be best, since the engine was originally painted after assembly, but removing the pan would then be tough if the nut holding the draft tube gets dropped installing the PVC 😁.
 
BTW: I sometimes forget, the hard copy literature we learned from (before the internet) is no longer readily available (unlike the shop manuals).
Obviously, it would be best to alter the pan (PVC clearance) before reinstall, assuming no concours restoration is planned
 
lbc3 said:
Thank, Jim. Makes sense. When you say "makes a mess", does that mean it could possibly be the source of the visible oil accumulation? Even so, it seems like a good modification so I will peruse the installation information on the site you referenced to see if I can manage it. Thanks again, Pete
Click to expand...
Jim,

I ordered the PCV conversion kit. But in the process of removing my carb it became clear this particular kit is not for my car. It seems I have a 4bbl carb given there are 4 openings in the base plate. I'm no gearhead so I couldn't tell the difference before. So I ordered another kit. But during some YouTube research I heard mention that carbs manufactured since the early 70's have a tube built in for a PCV. I don't see anything obvious, but I am thinking my carb certainly can't be "original". Pic attached; wondering if anybody can identify it by that.
 

Attachments

  • carb 4 .jpeg
    carb 4 .jpeg
    2.8 MB · Views: 7
  • carb 2 .jpeg
    carb 2 .jpeg
    3.6 MB · Views: 5
  • carb 5 .jpeg
    carb 5 .jpeg
    3.1 MB · Views: 5
  • PCV kit (2).jpeg
    PCV kit (2).jpeg
    1.6 MB · Views: 5
  • PCV kit .jpeg
    PCV kit .jpeg
    1.7 MB · Views: 5
Your carb looks like a teapot which was original on a 55 t-bird. The packaging for the conversion kit you bought says it is for a 57 two barrel carb,. I think you ordered the wrong part. You need CASCO part # 6758AA for a 55 Bird. Also there are numbers on the base of the carb towards the rear of the engine compartment. This should help you identify the carb for sure. Also your carb should have at lest 5 gaskets spacers between the carb and the manifold to help reduce heat soaking to the carb from the block. Yours does not have those. When you install the PCV kit you can dispense with that as the plate helps with that problem
 

Attachments

  • IMG_3425.jpeg
    IMG_3425.jpeg
    2.4 MB · Views: 4
You must log in or register to reply here.
Back
Top