How to fix Leaking C4?

[mickphatmac]

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?

[Viperwolf1]

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.

[mickphatmac]

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?

[Viperwolf1]

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.

[mickphatmac]

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!!!

[crawlercreations]

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!!!

I know this is going to sound silly but check your t case. Make sure it's in a gear! I've seen this happen before where someone installs a new transmission and the t case pops out of gear and it sure seems like the new transmission is junk. The grinding into park sounds like it's actually spinning the output but the t case is in neutral. It REALLY sounds like t case to me.

[mickphatmac]

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!!!

I know this is going to sound silly but check your t case. Make sure it's in a gear! I've seen this happen before where someone installs a new transmission and the t case pops out of gear and it sure seems like the new transmission is junk. The grinding into park sounds like it's actually spinning the output but the t case is in neutral. It REALLY sounds like t case to me.

Caught up in the moment THAT was clearly the last thing on my mind!!!
I will check Tcase next :)
Good call and thanks Jason!

[Kinder]

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.

[mickphatmac]

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.

Viperbuilt!!!
Let me know what you are asking for it and maybe we can make a deal with those shocks too?
Approx how many miles?

[Kinder]

Let me know what you are asking for it and maybe we can make a deal with those shocks too?
Approx how many miles?

We can definitely include the shocks in a deal, I don’t have a price in mind, you’ll get the “club” price for sure. I’ll guess it has 30-40k on it, we put it in the truck when Willem turned 16, so 7 years ago. It’s been in the garage for 2 of those years while we rebuilt it a 2nd time and he puts about 6k on it yearly.

[mickphatmac]

I know this is going to sound silly but check your t case. Make sure it's in a gear! I've seen this happen before where someone installs a new transmission and the t case pops out of gear and it sure seems like the new transmission is junk. The grinding into park sounds like it's actually spinning the output but the t case is in neutral. It REALLY sounds like t case to me.

Well I'll take being an idiot and being embarrassed every time OVER dropping that damn Transmission for a 3rd time!!!
We haven't had a chance to get it out of the garage since the weekend but the Boy put in into 2wd (from NEUTRAL) and it holds Park, surges into Reverse and wants to move forward in Drive!!! Woot WOOT!!!

We will clear a path to get it out of the garage again on Wednesday and see if we can't get it to run, and drive and shift gears and stop ;)
Thanks Jason!!

[mickphatmac]

We can definitely include the shocks in a deal, I don’t have a price in mind, you’ll get the “club” price for sure. I’ll guess it has 30-40k on it, we put it in the truck when Willem turned 16, so 7 years ago. It’s been in the garage for 2 of those years while we rebuilt it a 2nd time and he puts about 6k on it yearly.

That sounds perfect,
Thanks Kirk!!

[crawlercreations]

I know this is going to sound silly but check your t case. Make sure it's in a gear! I've seen this happen before where someone installs a new transmission and the t case pops out of gear and it sure seems like the new transmission is junk. The grinding into park sounds like it's actually spinning the output but the t case is in neutral. It REALLY sounds like t case to me.

Well I'll take being an idiot and being embarrassed every time OVER dropping that damn Transmission for a 3rd time!!!
We haven't had a chance to get it out of the garage since the weekend but the Boy put in into 2wd (from NEUTRAL) and it holds Park, surges into Reverse and wants to move forward in Drive!!! Woot WOOT!!!

We will clear a path to get it out of the garage again on Wednesday and see if we can't get it to run, and drive and shift gears and stop ;)
Thanks Jason!!

Glad it was something simple. Hope your transmission troubles are over!