Author Topic: Brake switch PSI ?  (Read 3272 times)

0 Members and 1 Guest are viewing this topic.

Offline Clifton

  • Hero Member
  • *****
  • Joined: Mar 2013
  • Location: Arizona
  • Posts: 747
Brake switch PSI ?
« on: Friday,April 19, 2024, 11:32:21 AM »
Has anyone dealt with a brake pressure switch that took too much pedal pressure to close the contacts? A casual stop is not enough on mine.

I can't find at what pressure these close at. I ordered a new one today and I will bench test both but I'm curious if this is common when they fail or do the just not work when they fail.

Offline BDA

  • Super Member
  • *******
  • Joined: Jul 2012
  • Location: North Carolina
  • Posts: 9,998
Re: Brake switch PSI ?
« Reply #1 on: Friday,April 19, 2024, 11:50:18 AM »
I had to change mine (from the original) but it's been a while so I'm not positive the failure mode. I think the brake lights would fail to come on. If I remember correctly, you could be experiencing the same thing. I just get a new one (3/8 - 24 thread) from any parts place and my brake lights work now.

Offline SwiftDB4

  • Sr. Member
  • ****
  • Joined: Jun 2016
  • Location: WA
  • Posts: 346
Re: Brake switch PSI ?
« Reply #2 on: Friday,April 19, 2024, 03:38:19 PM »
I got fed up with the hydraulic switch not activating with light pedal pressure so I fabricated a mechanical switch activated behind the pedal.

Offline Clifton

  • Hero Member
  • *****
  • Joined: Mar 2013
  • Location: Arizona
  • Posts: 747
Re: Brake switch PSI ?
« Reply #3 on: Friday,April 19, 2024, 04:44:57 PM »
Thanks BDA and Swift. I thought about a regular pedal switch. If I can just swap and be done it would save extra wiring.

New Lucas one is on it's way. I'll post what I find between the two.

Offline Clifton

  • Hero Member
  • *****
  • Joined: Mar 2013
  • Location: Arizona
  • Posts: 747
Re: Brake switch PSI ?
« Reply #4 on: Monday,April 22, 2024, 03:23:05 PM »
New Lucas switch takes between 80-100 psi. I don't know what mine on the car is closing at but I think I am going to add a micro switch at the pedal rather than swap and bleed to find it is the same set point. I want a brake light as soon as the pedal is moved not 100 psi at the rear brakes.

Offline dakazman

  • Super Member
  • *******
  • Joined: Jun 2016
  • Location: Florida
  • Posts: 4,230
Re: Brake switch PSI ?
« Reply #5 on: Monday,April 22, 2024, 06:04:30 PM »
New Lucas switch takes between 80-100 psi. I don't know what mine on the car is closing at but I think I am going to add a micro switch at the pedal rather than swap and bleed to find it is the same set point. I want a brake light as soon as the pedal is moved not 100 psi at the rear brakes.

  I can’t agree more and only noticed the delay recently. Then there is the 3rd brake light mod also.
Dakazman

Offline Clifton

  • Hero Member
  • *****
  • Joined: Mar 2013
  • Location: Arizona
  • Posts: 747
Re: Brake switch PSI ?
« Reply #6 on: Friday,May 03, 2024, 04:11:22 PM »
Switch is in. Bottom pivot pedals make it harder so I mounted it on the pedal. I drilled the brake and clutch arms previously and luckily the holes lined up.

Offline dakazman

  • Super Member
  • *******
  • Joined: Jun 2016
  • Location: Florida
  • Posts: 4,230
Re: Brake switch PSI ?
« Reply #7 on: Friday,May 03, 2024, 04:40:23 PM »
 Impressive work.
  I now understand the extension on the gas pedal.  I also didn’t realize all the small intricacies in the three.
 
Dakazman

Offline Clifton

  • Hero Member
  • *****
  • Joined: Mar 2013
  • Location: Arizona
  • Posts: 747
Re: Brake switch PSI ?
« Reply #8 on: Saturday,May 04, 2024, 03:36:35 AM »
The gas pedal :headbanger:  These Toyota DBW pedal are horrible and when in a light car, even worse.  To make it driveable under 30% throttle, I had to extend the arm more then I had to stiffen it to make it feel normal like our other cars. The shocks have thick RC silicone oil and add some resistance and slow the input like a cable. I have an adjustable oil damper to slow the closing on decel when I lift the throttle. It engages at 35%. It was the only way to be smooth going from the quick lift of gas to brake in autocross without the back wanting to come around.

Offline TurboFource

  • Super Member
  • *******
  • Joined: Sep 2019
  • Location: Maryland
  • Posts: 2,180
Re: Brake switch PSI ?
« Reply #9 on: Saturday,May 04, 2024, 04:01:01 AM »
I dislike DBW …..
The more I do the more I find I need to do....remember your ABC’s …anything but chinesium!

Offline BDA

  • Super Member
  • *******
  • Joined: Jul 2012
  • Location: North Carolina
  • Posts: 9,998
Re: Brake switch PSI ?
« Reply #10 on: Saturday,May 04, 2024, 08:03:18 AM »
Modern engine swaps involve a lot more modifications than I would have thought!

And then a buddy of mine who has a Zetec swap is having problems getting his tach to work with his ECU.

Offline Clifton

  • Hero Member
  • *****
  • Joined: Mar 2013
  • Location: Arizona
  • Posts: 747
Re: Brake switch PSI ?
« Reply #11 on: Saturday,May 04, 2024, 08:56:39 AM »
Modern engine swaps involve a lot more modifications than I would have thought!

And then a buddy of mine who has a Zetec swap is having problems getting his tach to work with his ECU.

I used a Speedhut tach and speedo. I had them put "SMITHS" on them. Not factory but they work good with EFI and have adjustable shift lights and lighted needles. I changed all my gauges to LED bulbs so they match.

Offline BDA

  • Super Member
  • *******
  • Joined: Jul 2012
  • Location: North Carolina
  • Posts: 9,998
Re: Brake switch PSI ?
« Reply #12 on: Saturday,May 04, 2024, 09:30:32 AM »
The Speedhut stuff is nice and the customizations are even nicer. I chose to stay with Smiths although it's kind of funny that the Speedhut speedo might not look any more different from the original speedo than my Smiths electronic (GPS driven) speedo!

I would think that his problem is either the ECU or the tach conversion, either should be addressed by the vendor but I'll suggest a Speedhut tach to my buddy if he can't get his converted tach to work with his ECU.