Hey guys,
I have an automatic C4 I installed in my ‘68 Bronco.
Yesterday when I ran it for the first time, it was leaking very badly out of the vacuum modulator and in “drive” it wouldn’t shift out of first?
I replaced the vacuum modulator and I have not had a chance to drive it yet but it is still leaking out of that port when I turn the engine on. (Leaking around the vacuum imput port) I also made sure that the bracket behind it is nice and tight.
Any ideas?

Early C4s had a threaded modulator until about 1972. Afterward it was a push in modulator with an o-ring. If its threaded make sure the threads are good and the case isn't cracked. Use sealant on the threads. If its a push in modulator make sure the bore is smooth and o-ring is good.

This one might be a job for Viperwolf1...
It’s one that you push in and like I said I got a new modulator for it with a new O-ring but the juice is still coming out!!!

Is there supposed to be transmission fluid all the way up to that point? Like if I remove the modulator is tranny fluid supposed to come out?

Yes, that's a little lower than the fluid level. You might have to let it drain so you can see if the bore is damaged.

Ok, we got the leaking Vacuum Modulator fixed and we added about 4 more quarts of Type F. Dipstick says it’s full.

Nothing! Nada! Zero! Crap!
No reverse, no drive no 1 or 2???
It grinds as it tries to go into Park but it doesn’t hold, you have to use the parking brake.
Is the Trans done or is it the torque converter?
Ugg!!!

If you need a trans, and I hope you don’t, we will be pulling TFB’s C4 out soon to put in a manual, damn kids. The trans is a known to us trans for 6+ years, originally rebuilt by Viper, it’s great and I wouldn’t remove it except my child thinks he wants a clutch, silly boy. Anyway let me know if I should set it aside for you or if you’d like to drive it before we pull it.