The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1947 - 1959 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 03-05-2017, 07:51 PM   #1
Curt - TN
Registered User
 
Join Date: Feb 2016
Location: Brentwood, TN
Posts: 138
Brake Switch Torque Converter lock out???

For those of you who of done an LS with a 4L60 or other electronic transmission and the master under the floor what have you done for a Torque Converter lock out when the brakes are applied?

I installed a inline brake pressure switch for the brake lights but I cannot find a dual switch to feed the signal to the computer to disengage the torque converter.

I may have to rig a manual switch to the peddle below the cab.
__________________
Curt
Brentwood TN
1950 Chevy 5 Window 3100 - Check out my Build Thread: http://67-72chevytrucks.com/vboard/showthread.php?t=724260
1957 GMC 100
Curt - TN is offline   Reply With Quote
Old 03-05-2017, 08:21 PM   #2
dsraven
Registered User
 
Join Date: Nov 2010
Location: calgary alberta
Posts: 8,323
Re: Brake Switch Torque Converter lock out???

can't remember exactly what the brake light switch looks like but it is a lever action afair right? just install another switch dedicated to the tcc, or install a relay off the existing brake light circuit to turn on/off the tcc when the brakes are applied/releasd. use "hot ign on" for a power supply so it is only powered when the key is on. just make sure to adjust the switch properly so the tcc releases fairly quick when the brake pedal is touched. an original switch would piggy back off the brake light switch with it's own power supply.
dsraven is offline   Reply With Quote
Old 03-05-2017, 11:48 PM   #3
AB6DO
Registered User
 
Join Date: Jan 2007
Location: near Fresno, Ca
Posts: 31
Re: Brake Switch Torque Converter lock out???

On my 1948 3100 I followed LT 1 Swap's directions on the brake switch. My master is under floor using stock brake pedal. I used an inline pressure switch for the brakes and a lever switch, like the original, for the TCC control.
AB6DO is offline   Reply With Quote
Old 03-07-2017, 10:08 PM   #4
_Ogre
Registered User
 
_Ogre's Avatar
 
Join Date: Jan 2012
Location: Motown
Posts: 7,680
Re: Brake Switch Torque Converter lock out???

easy peasy
this is how ogre did it

__________________
cool, an ogre smiley Ogre's 58 Truk build

how to put your truck year and build thread into your signature
shop air compressor timer
_Ogre is offline   Reply With Quote
Old 03-07-2017, 11:17 PM   #5
MIKESAD50
Registered User
 
Join Date: Feb 2014
Location: Sunnyvale, CA
Posts: 605
Re: Brake Switch Torque Converter lock out???

this was something I saw recently.
I'm going to try that to start with.

Ripped from the LT1swap.com site

Brake Switch Signal - For automatics with lock up converter, the PCM needs signal when brake pedal is pressed. However, the signal needed is opposite how you're brake lights work. The PCM wants 12v+ constant on this wire when brake IS NOT pressed, and OPEN Circuit when the brake IS pressed. If you vehicle was equipped with a lockup trans to begin with, you probably already have the proper normally closed switch mounted by your brake light switch. If you do not, you can use a relay to perform the same thing. On most relays, there are 5 terminals, 2 of them turn the relay ON when provided ground/power. There are then a normally open leg and a normally closed leg on the relay and a supply. By feeding 12v+ on the supply leg, and hooking the Brake Switch Signal wire to the normally closed leg, you will now have the correct signal for the PCM. When the brake is pressed, 12v+ flows to brake lights, tap into this wire, and run it to the relay to turn the relay on. This will cause the normally closed leg to become open, thus turning OFF the 12v+ signal to the PCM. When you release the brake pedal, the relay will turn OFF, and then feed 12v+ to the PCM.
Attached Images
 
__________________
1950 3100 5 window
MIKESAD50 is offline   Reply With Quote
Old 03-09-2017, 12:53 AM   #6
Curt - TN
Registered User
 
Join Date: Feb 2016
Location: Brentwood, TN
Posts: 138
Re: Brake Switch Torque Converter lock out???

Thanks for the ideas!
__________________
Curt
Brentwood TN
1950 Chevy 5 Window 3100 - Check out my Build Thread: http://67-72chevytrucks.com/vboard/showthread.php?t=724260
1957 GMC 100
Curt - TN is offline   Reply With Quote
Old 03-09-2017, 01:47 PM   #7
jweb
Senior Member
 
jweb's Avatar
 
Join Date: Apr 2010
Location: Oregon
Posts: 1,208
Re: Brake Switch Torque Converter lock out???

What happens if you don't hook up the TCC? I did my swap last year and wasn't aware of this.
jweb is offline   Reply With Quote
Old 03-09-2017, 02:01 PM   #8
Curt - TN
Registered User
 
Join Date: Feb 2016
Location: Brentwood, TN
Posts: 138
Re: Brake Switch Torque Converter lock out???

Quote:
Originally Posted by jweb View Post
What happens if you don't hook up the TCC? I did my swap last year and wasn't aware of this.
My understanding is the Torque converter will not unlock thus not allowing it to disengage when stopping or stopped. I am thinking this could cause a constant pull when in drive and could make it very hard to stop.

Have you been driving it ok?

I learned about this on my last build and had no idea either
__________________
Curt
Brentwood TN
1950 Chevy 5 Window 3100 - Check out my Build Thread: http://67-72chevytrucks.com/vboard/showthread.php?t=724260
1957 GMC 100
Curt - TN is offline   Reply With Quote
Old 03-09-2017, 03:04 PM   #9
jweb
Senior Member
 
jweb's Avatar
 
Join Date: Apr 2010
Location: Oregon
Posts: 1,208
Re: Brake Switch Torque Converter lock out???

Quote:
Originally Posted by Curt - TN View Post
My understanding is the Torque converter will not unlock thus not allowing it to disengage when stopping or stopped. I am thinking this could cause a constant pull when in drive and could make it very hard to stop.

Have you been driving it ok?

I learned about this on my last build and had no idea either
It does seem hard to stop, I thought that was a brake issue since I switched to rear disc and a new prop valve. Now I have to add this to my pre-summer to do list.
jweb is offline   Reply With Quote
Old 03-09-2017, 03:06 PM   #10
Curt - TN
Registered User
 
Join Date: Feb 2016
Location: Brentwood, TN
Posts: 138
Re: Brake Switch Torque Converter lock out???

Quote:
Originally Posted by jweb View Post
It does seem hard to stop, I thought that was a brake issue since I switched to rear disc and a new prop valve. Now I have to add this to my pre-summer to do list.
Yeah, the trans is always pulling without it. Glad you caught it now
__________________
Curt
Brentwood TN
1950 Chevy 5 Window 3100 - Check out my Build Thread: http://67-72chevytrucks.com/vboard/showthread.php?t=724260
1957 GMC 100
Curt - TN is offline   Reply With Quote
Old 03-09-2017, 04:13 PM   #11
jweb
Senior Member
 
jweb's Avatar
 
Join Date: Apr 2010
Location: Oregon
Posts: 1,208
Re: Brake Switch Torque Converter lock out???

Quote:
Originally Posted by Curt - TN View Post
Yeah, the trans is always pulling without it. Glad you caught it now
Now to figure out which wire goes where. I hate wiring.

I have an '04 GTO which list 2 different TCC wires

GY/RD 422 TCC Solenoid Valve Control

BN 418 TCC PWM Solenoid Valve

Any idea which one it is and which one on the transmission end?

Thanks for the help, sorry for hijacking your thread.
jweb is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 04:13 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com