Trans Brake Slow Release

NHRA1926 · 01-13-2016, 12:18 PM

I have a Turbo 400 manual valve body transmission with a Trans Brake. My problem is that when I release the thumb switch that is connected to the trans brake solenoid, there is a .5 to .75 second delay before the car actually moves. The switch is not hooked up to any delay box, it is wired directly to the trans brake solenoid. I tried activating the switch with the engine not running but with the electrical power on, and I can hear the solenoid does release as soon as I let go of the switch. Any ideas as to why this is happening?

FireSale · 01-13-2016, 01:20 PM

Give us more info on your torque converter and trans brake. Which companies made them? Did they come installed in the trans or did you do the conversion? What is the stall speed of the converter and what launch rpm are you using. Lots of stuff going on in there.

Dale

NHRA1926 · 01-13-2016, 02:20 PM

My Local Transmission shop guy did the rebuild and conversion for the trans brake. I remember he had to drill out an area in the valve body for the installation of the brake. I'm Using an Ultimate Converter's 5200 rpm converter. It doesn't matter what rpm the engine is at for the slow release. It's the same at idle as it is under full throttle with the two step at 2,000 rpm or 4,000 rpm. Is there a certain line pressure that the trans should be at when using a trans brake?

FireSale · 01-13-2016, 05:17 PM

I run a TCI Street Fighter C4 with a brake in my Mustang. They have a tech section at their site with a list of line pressures gear by gear for all transmissions they deal with, including the Turbo 400. Here's the link:

http://www.tciauto.com/tc/trans-line-pressure

Looks like 180-200 for a TB in a TH400 no matter what gear.

I've heard of drilling in a trans case to convert to brake and if it wasn't done correctly it could be your problem. My TCI came with a reverse pattern manual valve body with the trans brake built in.

If the line pressures check out take a look at the return spring in the solenoid setup. It's responsible for moving the pin out of the way to return the trans to normal operation. You should hear a very crisp snap when you release the button with the engine off.

Dale

ss3011 · 01-13-2016, 06:02 PM

Did your trans guy drill a bleed hole in the Direct Clutch housing, and add extra release springs to the Direct Clutch Apply Piston ? Both modifications are important for a clean release .

NHRA1926 · 01-14-2016, 12:35 AM

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 · 01-14-2016, 02:58 AM

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 · 01-14-2016, 05:49 PM

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 · 01-14-2016, 06:38 PM

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 · 01-15-2016, 10:16 AM

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.

01-13-2016, 12:18 PM	#1
NHRA1926 Member Join Date: Dec 2015 Location: Bowling green, Ky Posts: 230 Likes: 12 Liked 202 Times in 62 Posts	Trans Brake Slow Release I have a Turbo 400 manual valve body transmission with a Trans Brake. My problem is that when I release the thumb switch that is connected to the trans brake solenoid, there is a .5 to .75 second delay before the car actually moves. The switch is not hooked up to any delay box, it is wired directly to the trans brake solenoid. I tried activating the switch with the engine not running but with the electrical power on, and I can hear the solenoid does release as soon as I let go of the switch. Any ideas as to why this is happening?

01-13-2016, 01:20 PM	#2
FireSale VIP Member Join Date: Feb 2014 Location: Lakewood Washington Posts: 1,407 Likes: 29 Liked 237 Times in 126 Posts	Re: Trans Brake Slow Release Give us more info on your torque converter and trans brake. Which companies made them? Did they come installed in the trans or did you do the conversion? What is the stall speed of the converter and what launch rpm are you using. Lots of stuff going on in there. Dale __________________ Dale Shearon 68 Mustang 6394

01-13-2016, 02:20 PM	#3
NHRA1926 Member Join Date: Dec 2015 Location: Bowling green, Ky Posts: 230 Likes: 12 Liked 202 Times in 62 Posts	Re: Trans Brake Slow Release My Local Transmission shop guy did the rebuild and conversion for the trans brake. I remember he had to drill out an area in the valve body for the installation of the brake. I'm Using an Ultimate Converter's 5200 rpm converter. It doesn't matter what rpm the engine is at for the slow release. It's the same at idle as it is under full throttle with the two step at 2,000 rpm or 4,000 rpm. Is there a certain line pressure that the trans should be at when using a trans brake?

01-13-2016, 05:17 PM	#4
FireSale VIP Member Join Date: Feb 2014 Location: Lakewood Washington Posts: 1,407 Likes: 29 Liked 237 Times in 126 Posts	Re: Trans Brake Slow Release I run a TCI Street Fighter C4 with a brake in my Mustang. They have a tech section at their site with a list of line pressures gear by gear for all transmissions they deal with, including the Turbo 400. Here's the link: http://www.tciauto.com/tc/trans-line-pressure Looks like 180-200 for a TB in a TH400 no matter what gear. I've heard of drilling in a trans case to convert to brake and if it wasn't done correctly it could be your problem. My TCI came with a reverse pattern manual valve body with the trans brake built in. If the line pressures check out take a look at the return spring in the solenoid setup. It's responsible for moving the pin out of the way to return the trans to normal operation. You should hear a very crisp snap when you release the button with the engine off. Dale __________________ Dale Shearon 68 Mustang 6394 Last edited by FireSale; 01-13-2016 at 05:20 PM.

01-13-2016, 06:02 PM	#5
ss3011 Senior Member Join Date: Feb 2002 Location: Southeast Michigan Posts: 906 Likes: 70 Liked 237 Times in 112 Posts	Re: Trans Brake Slow Release Did your trans guy drill a bleed hole in the Direct Clutch housing, and add extra release springs to the Direct Clutch Apply Piston ? Both modifications are important for a clean release .

01-14-2016, 12:35 AM	#6
NHRA1926 Member Join Date: Dec 2015 Location: Bowling green, Ky Posts: 230 Likes: 12 Liked 202 Times in 62 Posts	Re: Trans Brake Slow Release 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.

01-14-2016, 02:58 AM	#7
FireSale VIP Member Join Date: Feb 2014 Location: Lakewood Washington Posts: 1,407 Likes: 29 Liked 237 Times in 126 Posts	Re: Trans Brake Slow Release 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. Attached Thumbnails __________________ Dale Shearon 68 Mustang 6394

01-14-2016, 05:49 PM	#8
Tom Goldman VIP Member Join Date: Jan 2003 Location: Allentown,PA Posts: 2,468 Likes: 874 Liked 838 Times in 232 Posts	Re: Trans Brake Slow Release 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. Attached Thumbnails __________________ Tom Goldman 1500 SG , 1506 STK

01-14-2016, 06:38 PM	#9
Tom Goldman VIP Member Join Date: Jan 2003 Location: Allentown,PA Posts: 2,468 Likes: 874 Liked 838 Times in 232 Posts	Re: Trans Brake Slow Release 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 . __________________ Tom Goldman 1500 SG , 1506 STK

01-15-2016, 10:16 AM	#10
NHRA1926 Member Join Date: Dec 2015 Location: Bowling green, Ky Posts: 230 Likes: 12 Liked 202 Times in 62 Posts	Re: Trans Brake Slow Release 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.