MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

TR parts and Triumph parts, TR bits, Triumph Car Spares and accessories are available for TR2, TR3, TR3A, TR4, TR4A, TR5, TR6, TR7, TR8, Spitfire and Stag and other TR models are available from British car spares and parts company LBCarCo.

Triumph TR6 - Brake Failure Switch Location

Can anyone tell me where the brake failure switch is located on a 73 TR6. Thanks
JW BRAW

Just under the master cylinder. At least it is in my 72 and all I've seen.

One thing if you have the opaque plastic reservoir be sure it is filling at the front. The main one has to be full to top before front fills.

Whats the problem?
Bill Brayford

Bill is prezactly right.

It's located on the main brake line distribution valve which mounts below the brake master cylinder. The switch screws into the distribution valve (aka proportional or proportioning valve) and senses pressure differential.

They are available used on Ebay or new from places like The Little British Car Company www.lbcarco.com who is one of the sponsors of this BBS.

hth,

Jim
Jim Deatsch

Jim, I am surprised at you...that cruise must have left you think to much about geese and not TR6 stuff. Sorry to disagree with you Jim but The Switch (white plastic)is screwed into the Pressure Differential Valve. The PDV is NOT a proportioning valve. Yes it senses difference in pressure. It does not "proportion" brake pressure to the front or back brake systems. I do not think you meant this:)
The sensed difference in brake pressure from the front 2 brakes to the back 2 brakes is what actuates the brake failure switch. A failure of either front or back brake systems causes a difference in pressure on either side of the sliding brass plunger (internal to the PDV) and raises a small metal rod which closes the contacts of the switch turning on the brake warning light at the dash.

Simply, The switch is located atop the PDV which is connected via 2 pipes directly to the Master brake cylinder and is mounted on the body of the car not the frame. One pipe is front brakes (the front of car one) the other (towards back of car)is back brakes. The front reservoir is front brakes the back reservoir is, well you guessed it, the back brakes.

After the PDV (front side pipe) is a 3 way hydraulic fitting (not a valve) mounted on the frame. This 3 way fitting is 1 in 2 out. The 2 out are to front L and front R. The other side or the PDV is a pipe to rear brakes and it goes to a 3 way fitting and does exactly like the front one.
Rick C
Rick Crawford

Yep, proportional valve is a carry over from my American rodding days.

I sit corrected.

Jim
Jim Deatsch

My problem is some #$%^ PO cut the wire coming out of the brake failure switch. The lamp has a white wire is is the +5 and a black wire with a purple stripe. The brake failure switch looks like it only has a black wire. So I am assuming I am going to have to run a new wire from the switch connector(gray) to the lamp. Hopefully that will fix it. The only problem is the guy cut the wire right at the switch. No way to splice it that I can see. Maybe the pin will pop out of the case and I can get a new one. ???
JW BRAW

JW
No fret lad.
Unscrew the plastiv switch from the brass PDV. Be carefull...it is plastic. With the aid of my key pad I will describe it to you.

0_0

That's it. It is not really a switch. The center thin bar has 2 round recepticles attached to it. So my little face actually has the horizontal line attached to both the 0s. When there is a brake failure the round rod is pushed up and contacts(touches) the center bar and you have a closed circuit and the light should come on.

When you have it off you will see that the Black Purple wire (that has been cut) is just a male pin in a female socket. Simply with needle nose pliers, pull it out. If you have (borrow the wifes) some eye brow twiezers you can actually pull out the 0_0 piece.
The new wire male pin can go in either of the 2 sockets.
Rick C
Rick Crawford

Wife's eyebrow tweezers. Yeah RIGHT!

I'd be on YOUR couch Rick. <G>

J
Jim Deatsch

This thread was discussed between 10/04/2004 and 14/04/2004

Triumph TR6 index