Jump to content

Rear Lights and Hydraulic Brake Switch


Recommended Posts

The rear lights are now working - new base plate and bulbs to remedy the damage caused by the naff LED's.

 

Q1 - to test the units when not fixed on the car I obviously needed to earth the socket - they weren't earthed before, should they be - the is a spare bullt on the plate which appears to be for an earth? The PO seemed to have relied on the screws through the base plate into the spire nuts for earthing ??

 

Q2 - still no brake light, even when the pedal is pressed hard, so going to replace the hydraulic switch. Can someone with my level of (in)competence replace it without having to bleed the brakes - is it a case of quick off, thumb over hole and quick on again ?

 

The switch I have ordered is 21B291 (chassis No. 26000#)

 

 

Moss doesn't seem to offer tapped or parallel options ? Also, I have read on other posts the suggestion of installing a copper washer - is there a specific type - again no suggestion in the boook.

 

 

PS - Q3 - where will I find the switch on the car ! :ph34r:

 

 

 

Link to post
Share on other sites

Hi Austin,

here is where the switch is located http://www.moss-europe.co.uk/shop-by-model/triumph/tr2-4a/brake-system/brake-controls-hydraulics/brake-pipes-girling-system.html #39.

 

As Menno states - do not remove the switch but consider using a BMW switch from ebay - cheaper than the original and they work and last.

some thing like this http://www.ebay.co.uk/itm/Brake-Light-Switch-BMW-3-Series-E30-E21-Volvo-240-940-850-760-740-240-/230958745598?fits=Car+Make%3ABMW&hash=item35c636c7fe:g:lT0AAMXQ71xRXtXx

 

On the 4A the switch is positioned just in front of the brake pedal where it joints the input shaft of the Master Cylinder.

I don;t know if this is possible on the 3/3A.

 

Roger

Edited by RogerH
Link to post
Share on other sites

Hi Austin,

 

I did the brake switch on my TR3 a couple of years ago, after I swapped a handfull of the hydraulic switches, they just kept mailfunction. I will post a photograph later. I used the TR4 switch, the only thing you need to do is enlarge the hole allready present in front of the brake pedal in the pedal box. Since then no worries.

 

Esben

Link to post
Share on other sites

You will be able to swap the switch and not have to bleed if you take the cap off the reservoir and then cover the open top with cling film and an elastic band to prevent siphoning. You should be able to see on your switch if there is a copper washer between it and the fitting. Have you checked to make sure it is the switch thats faulty? Join the two connectors together at the switch and turn ignition on will show you if its the switch or not. The original light fittings did indeed rely on the mounting screws for earthing though and extra earth wont go amiss.

Stuart.

Link to post
Share on other sites

Hi Austin ~

 

This is how I fitted the brake light switch to my 3A. (I think the switch is from a BMW?).

I wasn't happy with the original switch being so close to the exhaust system.

 

Tom.

attachicon.gifIMG_1379.JPG

 

 

 

I have also mounted a brake switch in the same way, mine was a cheapo citroen item but it works fine and only takes 20 minutes to install . The hydralic ones are a pain in the bum and they dont work very well being 50+years old now and the repro ones !!!!!

 

 

cheers

 

Alan

Link to post
Share on other sites

FWIW, my Saab 96 has the same hydraulic switch as the TR. 70s Saabs are a mix-match of Lucas and Hella parts. On the Saab, the hydraulic switch is mounted on the firewall. Guess what: in all those years (on two Saabs, one in the 80s and another one since 1998) these switches have never failed!

 

Menno

Link to post
Share on other sites

A number of folks have reported shorter brake switch life with DOT5 brake fluid (silicone) than with DOT3/4 (glycol). What brake fluid are you running, Austin?

Link to post
Share on other sites

A number of folks have reported shorter brake switch life with DOT5 brake fluid (silicone) than with DOT3/4 (glycol). What brake fluid are you running, Austin?

^^^ this ^^^

 

Forgot about that, but I've heard/read that somewhere too!

 

Apart from that, the position of the switch is awkward, to say the least. Heat, dirt, vibration and hard to reach when you need to replace it. I think that heat from the exhaust and dirt (wet!) from the road cause rapid temp changes. That will shorten the life of the switch as well, I suppose.

 

Menno

Link to post
Share on other sites

Hi Austin,

 

My switch is like Tom's. It's a quick and reliable fix and saves you having to break into the hydraulic brake circuit and it is an easy task to route the wires to the new switch position on the rear of the brake master cylinder 'box'.

 

Rgds Ian

Link to post
Share on other sites

Thanks all

 

This is what has arrived…..

 

 

IMG_0744_zps5snftfqm.jpg

 

Rog – I will try and find where that diagram sits on the car, but I am assuming its front bulkhead adjacent to exhaust ?!?

 

The switch behind the pedal looks a bit much for me to do, esp’ as I am doing this for the MoT and won't be worried about how many years it lasts

 

Thanks Stu – two weeks ago the brake light came on, but then disappeared again – but I can find no obvious faulty connections. I will fit the new rear light plates and a proper earth at the weekend before challenging the bullet connectors in the wires and the switches again just in case. To test, do i leave the existing wires in place and just connect the two terminals ?

 

I like the thought of the mechanical switch that Tom et al show, but not sure that I understand how its works ? What pushes the switch ? Also, do I just take the wires off the olde switch and stick them on the new one ?

 

Also, my set up seems to be slightly different to Tom’s in that at the front end of my box in which the forking ends to the pushy rods sit, there are bolts (old pics) - but the bolts don't seem to be doing anything obvious (to me :ph34r: )

 

5AE9A729-FB74-4991-8B44-DBE0A705174D_zps

 

A9AEDEA9-078C-4645-9D5F-32C516EFF9FD_zps

 

 

 

ps, Bob, I am pleased for you that at 61 years of age it still works B)

Link to post
Share on other sites

...I like the thought of the mechanical switch that Tom et al show, but not sure that I understand how its works ? What pushes the switch ? Also, do I just take the wires off the olde switch and stick them on the new one ?...

 

The spring-loaded switch "closes" when the brake pedal lever moves. (It's normally in the "open" position.)

 

The more common mounting, IME, is to have it under the dash where it's protected and out of site. See Menno's photos for his example -- I can probably find others too, 'cause it's a fairly common mod over here.

Edited by Don H.
Link to post
Share on other sites

Hi Austin,

 

Take out the bolt that is behind the brake pedal and replace it with the mechanical switch. It is a switch that is normally closed circuit (i.e. on) but when you press it is opens the circuit, (i.e. switches off). You adjust the switch button so that when you press the brake pedal the back of the lever that sits in the forks of the master cylinder push rod, moves away from the switch allowing it to pop out under pressure from the spring inside the switch and hence completes the circuit and allows the brake lights to come on. When you take you foot off the brake pedal it all goes into reverse and the switch button is depressed which opens the contacts in the switch and turns the brake lights off. Simples!

 

Rgds Ian

 

Here is a link to a suitable switch:

 

https://iapunitedkingdom.com/sku/61311368786/29/?adtype=%7Badtype%7D&gclid=Cj0KEQjw4fy_BRCX7b6rq_WZgI0BEiQAl78ndz2OnWIsShRuTXs7k5-DgTAV61-YK5uixtaYbMkrZ-caAnwx8P8HAQ

Edited by Ian Vincent
Link to post
Share on other sites

Austin, read my post #6 again carefully and it does tell you how to test the switch first before doing anything else. Just join the cables by the switch turn ignition on and see if the brake lights come on.

Stuart.

Link to post
Share on other sites

Hi,

 

I recently did a bit of rustproofing (Dinitrol) behind the rear arches in the dirt pocket behind the rear lights. Afterwards my brake lights no longer worked. Thought I may have disturbed wiring etc. not the case. I happened to be at a TR Register meeting and one of the group connected a spare wire direct to earth the earth terminal, all was OK. I think the self tappers which earth the light unit were just too fragile and perhaps the rustproofer provided some insulation? I simply put a self tapper screw, one size up from the old ones through the unit into the body, with a quick squirt of rust proofer lbehind and hey presto, all worked fine again.

 

Are sure it's not just a simple earthing problem?

Edited by Mart O
Link to post
Share on other sites

Austin

I like the expansion tank set up. Is it your manufacture or are they available ?

H

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...

Important Information

Please familiarise yourself with our Terms and Conditions. By using this site, you agree to the following: Terms of Use.