1968 NEED SOME HELP:C4 vent tube leaking fluid

[anthony m]

I recently purchased a 68 GT/CS that had been parked since 1981 due to a transmission leak. The transmission was pulled and it sat until 5 months ago. I was told that the transmission shifted fine, but had a massive leak when the engine was running. Before installing the transmission I replaced the front and rear seals and their was no indication of any leaks from these areas. The guy I bought the car from couldn't remember where he thought it was leaking from. Yesterday, I was at the point where I could fill the tranny and I overfilled the tranny and it poured out the overflow vent tube. No big deal, but I wonder if this is where the leak was from before. I have read that if the wrong dip stick was installed at some point in time that you could actually overfill the tranny when the stick reads fine. I also read that there could be a check valve inside the tranny that causes fluid to dump out the vent tube. What length dip stick should I have? I will probably try and start the car today and see what happens. Any imput would be great.

Thanks,
Anthony

 

[franklinair]

Now I gotta dig out my manuals. Where the heck is a vent tube? I'll measure the dipstick on my C-4, and also see if there is a P/N on it.

Neil

 

[anthony m]

Neil,

There is a steel vent tube that comes down from the top of the tranny and makes a 90' bend on the left side of the tranny (safety switch side). I did fire the old girl up today. It had been 28 years since it was last started and it ran great with no signs of any leaks. I still need to do the brake system though (no brakes).

How sensitive is the shift linkage adjustment? I tried to visually position the shifter where it appeared to have been set years ago, but it seemed like the car wanted to lurch backwards somewhat as it was running. I had the wheels chalked so the car couldn't move.

Anthony

 

[franklinair]

With the shift rod linkage disconnected, push the short lever on the C-4 all the way aft. The trans is now in Park. Put the gearshift selector in Park. Now connect the shifter linkage to the transmission lever, and they are now in sync. Happy motoring!!

Neil

 

[anthony m]

Neil,

Thanks for the info. I will try that sometime this week. Let me know about the dipstick length or part # when you can.

Best regards,
Anthony

 

[robert campbell]

Neil,
I have just had experince in this. Neutral is the best position to adjust an automatic shift linkage. I put my cars in neutral to adjust the linkage.

I am going to consult my automatic guru on the fluid through the vent tube thoughts. My gut says no way.

Rob

 

[franklinair]

It'll work either way. It's just a matter of coordinating the tranny position to the selector position.

Neil

Rob, PM me on how you adjusted the kickdown linkage. Gotta do that on mine. (Guess I could breakdown & read the manual):icon_pani

 

[di81977]

Cars are in storage, went and visited them this morning. Forgot to check length, but took these pictures. Can't tell you for sure it is the correct C4 dip stick, but I have no reason to believe it is not. No part number, but it does have the ford motor co stamping up by the handle.

Hope this helps.
David

 

[patty.dilabio]

Hi to all C4 owners.I learned this many years ago,after storing for several months made a puddle on the nice clean garage floor.It is the result of what Ford calls excessive converter drainback,and because the car sat without running,the converter check valve allowed the transmission to overfill,and puke out the vent tube.The secret is to simply drain the converter of its fluid if you are going to store the car without running it.An improper dipstick would easily allow you to overfill the transmission and also let fluid out the vent.Follow the fill procedure in the shop manual,and live on leak free!

 

[robert campbell]

Neil,
I spazed out and did not see you kick down adjustment question. This is what I do.

Put the car in park. First I ensure that the current adjustment on the throttle rod from the firewall will achieve full opening of the carb. Or the pedal is somewhere around 4.5 inches from the floor pan. Either way you want the carb completely opened. Go under the car and remove the cable for the kick down from the throttle linkage end. Leave the cable attached to the tranny. Now block the throttle fully opened or have someone hold it down. Now go under the car and push the kick down lever in a counter-clockwise direction until it hits the internal stop in the tranny and hold it. Now stretch the cable towards the attachment point on the throttle linkage. Spin the adjuster on the cable until it fits into the hole on the linkage. Then turn it clockwise in one turn to sort of pre-load it a bit. This is the standard Ford recommended method.

I would then take it out and try it. First try a full throttle run from first to second gear. The kick down adjustment can affect when the tranny shifts from 1st to 2nd and 2nd to 3rd. I loaded my C6 a bit much and it held it in gear to long and I am not sure how long it would have held it in, but I was at 6,000 rpm. Anyway be certain to try it and be ready to let off. I found that for each turn on the kick down adjustment it changed the shift point about 100 rpm. Can’t remember which direction. Anyway some fine tuning got me where I could just leave it in drive and the auto snapped of perfect 5,800 rpm shifts and downshifted perfectly from drive to 2nd.

Hope this helps.

Rob

 

[robert campbell]

Patty,
So what you said makes sense. But if the convertor leaks down and puddles a bit, the reverse should happen when you start the car up. The convertor would be low and it would then suck up the excess in the tranny and equalize it minus the puddle if rocked in and out of gear. Then it would stop leaking.

Anthony,
Is it continuing to leak? You would need to rock it into drive and reverse a few times for the pump to draw out the fluid back into the convertor.

The wrong dipstick is a posibility.

Rob

 

[franklinair]

I measured the C-4 dipstick (original). No P/N, length is 19 7/8" from inner side of cap to the tip.

Neil

 

[anthony m]

Tranny leak

Rob,

I haven't noticed any more fluid leaking from the overflow tube. I was sure that I would have seen more ATF leaking out of the overflow tube after I started it, but it must have been started to circulate thru the system. I haven't messed around with the car much in the last week. We have been pounded with snow in N. E. Ohio and W. Pennsylvania. I will check the legnth of the dip stick tonight.

Anthony

 

[robert campbell]

Anthony,
Sounds like Patty was right on! Convertor, which countains about 8 quarts, drains back into auto and drips out overflow/vent tube. You do not need to drive it. Just rock it in and out of gear at idle and it will pump back into the convertor. Rock it in and out of reverse to. Check the fluid level when done and it should be a bit low. Top it off and see if it leaks again.

I have a 56 T-bird in storage (anyone want one?) that I start on a monthly basis and rock it in and out of gear. Keeps the seals lubed and no leaks.

Rob