I got questions, you got answers, I know you do! 71 302 C4

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RIBS

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A couple questions on two subjects,

I have the standard puddling of transmission fluid under the car after it sits. I don’t drive it much because it’s being rebuilt. But it just pushes transmission fluid out to the floor, I don’t see any specific leaks and I’ve never actually located the overflow tube, anybody have good pictures or drawings of that? The other half of the equation is what’s the source Of the leak is it some sort of flow back valve in the torque converter, what causes a leak like this and how do you fix it? Of course I want a simple fix. I have replaced the band adjustment seals and don’t see any drips around linkage or speedo cable.

The other question is crank case ventilation, I bought the car in this configuration, a hose out of the passenger side rear valve cover connected to the intake, and just a breather cap on the front driver’s side of the Valve cover..I get a little bit of oil smoke out the driver side cab when idling. What’s the proper configuration for pulling fumes out of the valve covers? I have a Edelbrock 1405 carburetor with performer 289 intake. Do I need additional connections to vacuum on the intake?

send me pictures and replies!
 

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Hemikiller

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C4 vent is either a tube on the driver's side of the main case, or on later transmissions, a poppet vent at the top of the case. Ken from BadShoe covers it really well in his video.


Most common leaks are the dipstick tube o-ring and the pan gasket. Dipstick tubes can also be bent out of true, or cracked at the o-ring area.

The converter anti-drainback valve is held in by the filter, and often gets lost.

1641673983059.png


As far as the PCV setup, you have a PCV there, but it's capped off. Use a piece of 3/8" hose to connect it to the PCV port on the front of your Edelbrock. If you prefer, grab a PCV with a 90° nipple on the end. I usually just grab one off the rack at the parts store. You will have to readjust your idle mixture and speed to account for the extra air. You may also need to tweak your accelerator pump and re-tune the carb (springs/rods/jets).



edelbrock_vacuum.JPG
 

RIBS

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C4 vent is either a tube on the driver's side of the main case, or on later transmissions, a poppet vent at the top of the case. Ken from BadShoe covers it really well in his video.


Most common leaks are the dipstick tube o-ring and the pan gasket. Dipstick tubes can also be bent out of true, or cracked at the o-ring area.

The converter anti-drainback valve is held in by the filter, and often gets lost.

View attachment 58585


As far as the PCV setup, you have a PCV there, but it's capped off. Use a piece of 3/8" hose to connect it to the PCV port on the front of your Edelbrock. If you prefer, grab a PCV with a 90° nipple on the end. I usually just grab one off the rack at the parts store. You will have to readjust your idle mixture and speed to account for the extra air. You may also need to tweak your accelerator pump and re-tune the carb (springs/rods/jets).



View attachment 58586
So if that drain back valve fell out during an oil change, I would get fluid draining back? Does it come as part of a filter and fluid change or would I have to buy it? Interesting, my C4 has dipstick going into body, not pan, like a 70’s style, I have a 12/70 build, and who knows if it’s an original transmission…more research I guess…
 
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Hemikiller

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So if that drain back valve fell out during an oil change, I would get fluid draining back? Does it come as part of a filter and fluid change or would I have to buy it? Interesting, my C4 has dipstick going into body, not pan, like a 70’s style, I have a 12/70 build, and who knows if it’s an original transmission…more research I guess…

Pan fill were only used in full size, intermediates (Fairlane, Torino, Montego) and trucks starting in 1970, and it was typically only used behind a 351-2V engine in the car lines. Ford continued to use case fill until the end of C4 production in 1981. Pan fill passenger car units were PEF-xx coded on the tag. 71-73s used a PEE-xx code C4 transmission.

If the fluid is coming out the vent, then I'd say you need to see if that anti-drainback valve is present. However, my first step would be to clean the case of the trans, as well as inside of the bellhousing with brake clean, blow it dry and place cardboard under it until you see a drip. You can dust the case with talcum powder, which will show a trail of where the leak is originating. My first suspect is always the dipstick o-ring and pan gasket, but fluid can travel.
 

Spike Morelli

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Hemikiller, your advise is well taken, and, I myself was just about to reply to the PCV question. Kudos to you in showing the Edelbrock/Carter AFB PCV hose nipple at the front of the carb. Because Ford and Holley have PCV hook-up at the rear ( some Holleys on the side ), I've seen well meaning owners go to great lengths to add a spacer with a nipple at the back, because they weren't aware that it was at the front on those carbs. Some guys mistakenly plumb into the power brake port . It's all easily rectified.
As to the fluid leak, there's also potential to leak from the speedo cable o-ring seal, as well as from the cable itself depending on the condition of the cable. Possibly a front pump seal needs attention too, or even a modulator seep.
 

RIBS

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C4 vent is either a tube on the driver's side of the main case, or on later transmissions, a poppet vent at the top of the case. Ken from BadShoe covers it really well in his video.


Most common leaks are the dipstick tube o-ring and the pan gasket. Dipstick tubes can also be bent out of true, or cracked at the o-ring area.

The converter anti-drainback valve is held in by the filter, and often gets lost.

View attachment 58585


As far as the PCV setup, you have a PCV there, but it's capped off. Use a piece of 3/8" hose to connect it to the PCV port on the front of your Edelbrock. If you prefer, grab a PCV with a 90° nipple on the end. I usually just grab one off the rack at the parts store. You will have to readjust your idle mixture and speed to account for the extra air. You may also need to tweak your accelerator pump and re-tune the carb (springs/rods/jets).



View attachment 58586
One more quick question, I do have a hose going between passenger side valve cover and the air filter assembly, is it OK to pull from both valve covers at the same time? I thought you would need an air in, and and air out…
 

Hemikiller

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Your passenger vent setup is fine, that's pretty much how Ford did it. The air cleaner supplies fresh air to the crankcase, the PCV pulls out the fumes.
 

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