Home  |  Forums  |  914 Info  |  Blogs
 
914World.com - The fastest growing online 914 community!
 
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG. This site is not affiliated with Porsche in any way.
Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners.
 

Welcome Guest ( Log In | Register )

 
 Reply to this topicStart new topic
> How do you reset the master cylinder brake switch, The 2 wire type
913B
post Sep 5 2016, 08:30 PM
Post #1


Senior Member
***

Group: Members
Posts: 854
Joined: 25-April 05
From: South Bay/SoCal
Member No.: 3,983
Region Association: None
The brake switch on my master cylinder has 2 wires. I didn't see any reset button. When I unplug the brown/white signal wire going to the brake light in the gauge. The brake light will respond accordingly to the hand brake and go out. Before it would stay lit all the time regardless if the handbrake was applied or released.

So the question is how do you reset the brake switch or do I need to bleed the brakes ??

The brake light was working fine until the transport company moved my vehicle. I think the driver may have applied the brakes too hard maybe (IMG:style_emoticons/default/confused24.gif)

Let me know you thoughts.

Thanks everyone ! (IMG:style_emoticons/default/driving.gif)
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Krieger
post Sep 5 2016, 09:36 PM
Post #2


Advanced Member
****

Group: Members
Posts: 4,769
Joined: 24-May 04
From: Santa Rosa CA
Member No.: 2,104
Region Association: None
The reset is on the left side of the master cylinder. You can get at it without lifting the car. Turn the steering wheel all the way to the right. Get a flashlight. It is a small rubber protusion maybe 5mm on the left side. Just push it back in. You also might want to check the switch under the handbrake. It is on the crossmember. It may be stuck, broken or corroded. It is also possible the handbrake is not making contact with the switch and is not pushing the switch down when you put the brake handle down. My gauge light flashes red when the e-brake handle is up.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
913B
post Sep 5 2016, 10:03 PM
Post #3


Senior Member
***

Group: Members
Posts: 854
Joined: 25-April 05
From: South Bay/SoCal
Member No.: 3,983
Region Association: None
QUOTE(Krieger @ Sep 5 2016, 08:36 PM) *

The reset is on the left side of the master cylinder. You can get at it without lifting the car. Turn the steering wheel all the way to the right. Get a flashlight. It is a small rubber protusion maybe 5mm on the left side. Just push it back in. You also might want to check the switch under the handbrake. It is on the crossmember. It may be stuck, broken or corroded. It is also possible the handbrake is not making contact with the switch and is not pushing the switch down when you put the brake handle down. My gauge light flashes red when the e-brake handle is up.

Is it on the switch itself ?? I don't suppose someone has a pic ? I even took the wheel out and didn't see any switch though? I want to fix it so I can pass my vehicle inspection for my registration.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
913B
post Sep 5 2016, 10:06 PM
Post #4


Senior Member
***

Group: Members
Posts: 854
Joined: 25-April 05
From: South Bay/SoCal
Member No.: 3,983
Region Association: None
QUOTE(Krieger @ Sep 5 2016, 08:36 PM) *

The reset is on the left side of the master cylinder. You can get at it without lifting the car. Turn the steering wheel all the way to the right. Get a flashlight. It is a small rubber protusion maybe 5mm on the left side. Just push it back in. You also might want to check the switch under the handbrake. It is on the crossmember. It may be stuck, broken or corroded. It is also possible the handbrake is not making contact with the switch and is not pushing the switch down when you put the brake handle down. My gauge light flashes red when the e-brake handle is up.

The handbrake part works fine. With the signal wire that goes to the gauge disconnected. The handbrake operates the brake light fine. Thanks for tip
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Krieger
post Sep 6 2016, 09:33 AM
Post #5


Advanced Member
****

Group: Members
Posts: 4,769
Joined: 24-May 04
From: Santa Rosa CA
Member No.: 2,104
Region Association: None
Post a pic of your master cylinder
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
North Coast Jim
post Sep 6 2016, 12:02 PM
Post #6


Member
**

Group: Members
Posts: 331
Joined: 11-December 15
From: Northern Ohio
Member No.: 19,450
Region Association: MidAtlantic Region
QUOTE(porsche913b_sp @ Sep 5 2016, 10:30 PM) *

The brake switch on my master cylinder has 2 wires. I didn't see any reset button. When I unplug the brown/white signal wire going to the brake light in the gauge. The brake light will respond accordingly to the hand brake and go out. Before it would stay lit all the time regardless if the handbrake was applied or released.

So the question is how do you reset the brake switch or do I need to bleed the brakes ??

The brake light was working fine until the transport company moved my vehicle. I think the driver may have applied the brakes too hard maybe (IMG:style_emoticons/default/confused24.gif)

Let me know you thoughts.

Thanks everyone ! (IMG:style_emoticons/default/driving.gif)


Just reworked my entire brake system with help from PMB Performance. Replaced the master cylinder as well. I too had the persistent "brake" light flashing/alarm and didn't know how to remedy the situation. Was told by Eric at PMB that I needed to reset the switch. Since I had the car up on stands I could easily get to the master cylinder again. Removed the boot protecting the two electrical wires. Adjacent to the two electrical posts is the switch, not really a switch since all you have to do is push it in. It is only a protrudence of plastic and not easily recognized as a switch. Push on it while the key is turned to the on position. You will hear the cessation of the brake alarm. The brake light will stop blinking. Easy. I've had to do this twice now once with the car on the ground.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Kansas 914
post Sep 6 2016, 12:12 PM
Post #7


Advanced Member
****

Group: Members
Posts: 2,999
Joined: 1-March 03
From: Durango, Colorado
Member No.: 373
Region Association: Rocky Mountains
It is the black "shaft" in this picture.

Attached Image
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
913B
post Sep 6 2016, 01:07 PM
Post #8


Senior Member
***

Group: Members
Posts: 854
Joined: 25-April 05
From: South Bay/SoCal
Member No.: 3,983
Region Association: None
I wish I had a pic of my switch the center part is like a plastic divider. It is slightly different design than yours (IMG:style_emoticons/default/sad.gif)
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
913B
post Sep 8 2016, 09:36 PM
Post #9


Senior Member
***

Group: Members
Posts: 854
Joined: 25-April 05
From: South Bay/SoCal
Member No.: 3,983
Region Association: None
So I have come to the conclusion there is no reset button on the early 2 wire brake switch.

I even tried reversing the connections, but no such luck,

The short term fix is leaving the brown/white signal wire unplugged from the switch. The brake light on the gauge will only be controlled by the hand brake lever.

The long term fix is next time I am under the vehicle. I'm going to swap out the switch with the single pole type with the reset switch.

That is my update for now.

(IMG:style_emoticons/default/beerchug.gif) (IMG:style_emoticons/default/beerchug.gif)
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Garland
post Sep 8 2016, 10:20 PM
Post #10


Restoration Fanatic
***

Group: Members
Posts: 1,397
Joined: 8-January 04
From: ......Michigan......
Member No.: 1,535
Region Association: Upper MidWest
I have the same concern, have left the one wire loose. I think the switch is bad. Going to replace it with a 2 pole switch.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
913B
post Sep 8 2016, 10:41 PM
Post #11


Senior Member
***

Group: Members
Posts: 854
Joined: 25-April 05
From: South Bay/SoCal
Member No.: 3,983
Region Association: None
you want to switch to 2 pole ?? You mean to replace it with 1 pole with the reset button ?
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Garland
post Sep 8 2016, 11:36 PM
Post #12


Restoration Fanatic
***

Group: Members
Posts: 1,397
Joined: 8-January 04
From: ......Michigan......
Member No.: 1,535
Region Association: Upper MidWest
QUOTE(Garland @ Sep 8 2016, 10:20 PM) *

I have the same concern, have left the one wire loose. I think the switch is bad. Going to replace it with a 2 pole switch.



I have 2pole now. With one wire unpluged.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Dave_Darling
post Sep 9 2016, 09:55 AM
Post #13


914 Idiot
***************

Group: Members
Posts: 15,063
Joined: 9-January 03
From: Silicon Valley / Kailua-Kona
Member No.: 121
Region Association: Northern California
I have a two-pole switch with a reset button...

My understanding is that the switches without reset buttons do not "latch", so that when the pressure balance is removed they turn off themselves.

Do you have a good photo of your switch?

--DD
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
NoEcm
post Sep 9 2016, 10:35 PM
Post #14


Member
**

Group: Members
Posts: 95
Joined: 20-June 05
From: Seattle, WA
Member No.: 4,309
I just installed a new single pole switch because the old one was leaking brake fluid.

The defective one had a little reset button you you could depress.

The new switch that I just installed does not have a reset button.


Pictured below is the defective switch that I purposely tripped for this thread. Push the little nub back in and the switch gets reset.

Attached Image
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
913B
post Sep 11 2016, 04:50 PM
Post #15


Senior Member
***

Group: Members
Posts: 854
Joined: 25-April 05
From: South Bay/SoCal
Member No.: 3,983
Region Association: None
Thanks everyone for the contributions. I want to see the reset sw on the 2 pole type if there is such a thing ?

(IMG:style_emoticons/default/beerchug.gif) (IMG:style_emoticons/default/smilie_pokal.gif)
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
« Next Oldest · 914World Garage · Next Newest »
 

Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 

Display Mode: Standard · Switch to: Linear+ · Switch to: Outline

Track this topic · Email this topic · Print this topic · Subscribe to this forum

- Lo-Fi Version Time is now: 26th December 2024 - 12:48 PM
Invision Power Board v9.1.4 © 2024  IPS, Inc.
All rights reserved 914World.com © since 2002
914World.com is the fastest growing online 914 community!
We have it all, classifieds, events, forums, vendors, parts, autocross, racing, technical articles, events calendar, newsletter, restoration, gallery, archives, history and more for your Porsche 914 ...