Trans Brake Slow Release

[NHRA1926]

Not sure about the bleed hole in the direct clutch or the extra springs. Not sure if I would understand where the "Pin" is for the brake solenoid but maybe my tranny guy will. I did down load the pressure chart from the TCI sight that you offered and I'm gonna bring that to my tranny guy and see if he set my line pressure near those numbers. I appreciate all the help as I have the tranny out right now to replace the converter that I had built by Lenny at Ultimate Converters, and I'd like to fix it while it's out of the car. Snow is on the ground here in upstate NY but I don't wanna wait till the last minute to get this figured out before spring weather comes around. Thanks for the info guys.

[FireSale]

This is what I mean by a "pin". The solenoid pushes this valve in when it's engaged to lock your trans. It's milled differently from a stock valve. What we keep calling a TB solenoid is a modulator valve on a stock auto trans. It's run (usually) off a vacuum line and changes flow of fluid in the trans depending on how hard the engine is working.

If this piece is sticking or the return spring is weak, it would slow your TB response time.

This part is from a TH 350 TB from TCI.

[Tom Goldman]

I didn't mention in my response to your question which was also on the .90 tech forum, If you are using a TCI brake the removal of the casting wall is critical for proper release .
I have had a trans in the shop that did not have this done and it was slow , not to your extreme , but slow.
Also how does the trans engage and release reverse ? does it react normally ?
If reverse is abnormal so will be brake release.
JW brakes also require the use of their regulator spring and reverse /rear accumulator spring.
here's a shot of the divider that must be removed for the TCI brake.

[Tom Goldman]

Been thinking about this further , was this a new build or an update to a trans that previously had a manual vb in it ? ...some Builders and valve body manufacturers plug one of the direct clutch passages in the center support or in the case itself . ....that could cause the fluid path from the direct clutch to be obstructed ,delaying the release ......certainly worth looking at during disassembly .

[NHRA1926]

Great ideas from every one. Thank you. Fall of 2014 my Transmission stopped going into 2nd & high gear while coming down the return road after a pass down the track. I pulled it out and brought it to my tranny guy. When he pulled it apart, he found that most of the "Lugs" in the case were stripped and the high gear drum surface was badly scored . I brought him another turbo 400 to use so he could make one good one out of the two trannys. He used the case and high gear drum from the second tranny but all other internals from the original transmission were good so he re-used them. I'm wondering if he removed the passage in the case for the trans brake and drilled the hole in the drum of the second tranny I brought him to use. Also wondering if he used all the springs that were in my original trans that came with the valve body kit from TCI for the trans brake solenoid valve, direct high gear clutch pack and pressure regulator? I just printed off the instructions from TCI for the valve body kit and I am going to bring them to him. Hopefully he remembers if he swapped all these key components and did the modifications to the case and drum! I know that's a big if but its a start. I might just end up bringing it to Jack Sepanek in PA to rebuild it. Several people highly recommend his work. Only problem is that he is 4 hours away from my house. Again thanks for all the advice and suggestions. It sure is nice knowing there are people out there willing to help.

[FireSale]

My C4 went a similar route. It was a TCI StreetFighter that kept blowing converter seals. I figured something was screwy with the case and bought a newer C4 case. I had a local trans shop rebuild the two into one. In the process I found a badly chipped forward solenoid piston and ordered an aftermarket part from PA Auto. Added a 6 gear pinion at the time, too. The shop didn't specialize in racing autos so I was very clear with them as what should be replaced with what. It worked out OK, but I was really considering a stick for a while.

Dale

[Tom Goldman]

I'm a trans guy and if I was going to recommend someone other than myself it would be Jack.
If you stay close to home ,be sure your builder uses an intermediate clutch support/case saver. The higher line pressures stress one of the few weak spots of the TH400.
I prefer Rosslers piece ,simple and strong . reasonable price too .