Brakelight Switch Replacement

[Myrtles Man]

Just discovered that I've inadvertently been driving around for lord knows how long with inoperative brake lights. Oops! Fortunately, the brakes on my car have been so incredibly feeble (I've now replaced comprehensively seized cylinders and renewed the brake shoes) that no following driver would have been in the slightest danger of rear-ending me (since acquiring the car I've re-developed forward-observation and anticipation skills that would be the envy of a cobra-fighting mongoose!)

Anyway, thing is, I've established that it's the brakelight switch letting the side down and I have a new one on order. What I'm hoping for here is words from the wise about how to go about the removal and replacement process without getting air into the system and having to do (yet another!) all-round bleeding brake-bleeding exercise. How do the old pro's go about it?

[newagetraveller]

As long as you unscrew the old one carefully and screw the new one in right away without pressing the brake pedal there shouldn't be a problem.

[simmitc]

As above, it should not be a problem, but unscrewing the old one can be. Make sure that you support the union to stop it twisting. A deep socket or box spanner is the best tool to hold the switch.

Have your brakes been modified in any way? Discs, servo, remote fluid reservoir? These can make the job even easier, but it's always worth checking when talking about brakes. Before fitting the new switch, hold it upside down and dribble or inject clean fluid into it, then keep your finger over the hole until the very last second as you fit it. Surface tension will hold the fluid in there for a moment and prevent air getting trapped in the switch.

[paul 300358]

Before starting, cover the top of the master cylinder with cling film. Also, get everything ready and prepared.

[Myrtles Man]

Thanks all for your helpful responses. Seems more straightforward than I'd feared. The brakes are still standard Minor fare with no additions. I like the tip about filling the switch with fluid first simmitc as, from a Rob Thomasson article a few years ago, it seems it's quite possible for an air bubble to lurk in the top of the switch. If that were to happen, presumably there's no easy way of directly bleeding it out. Would having the front wheels up in the air on ramps before changing the switch over be worth doing? I'd already picked up the clingfilm tip Paul but thanks for ensuring that I knew about it, it's appreciated.

[JOWETTJAVELIN]

There is a useful Lucas gadget called a Stop Lights Indicator which serves two purposes; first it proves your brake lights are working and secondly it warns of bulb failure or total failure. I have one of these fitted to my cars. Otherwise the time-honoured method of checking they operate by looking at reflection in a shop window still works.

[jagnut66]

There is a useful Lucas gadget called a Stop Lights Indicator

Sounds interesting, I haven't heard of this before and an internet search doesn't bring it up, do you have a picture or a link to one?
Many thanks,
Mike.

[geoberni]

There's some currently on ebay: https://www.ebay.co.uk/itm/Lucas-33178- ... SwUCdexUO2

I can't readily explain why there are 3 terminals on them* , but basically any small indication lamp, supplied from the down circuit side of the brake switch, will tell you if it's working or not.
if you want to know if the actual Stop lamps are working, rather than just the Brake switch, then you need a small bulb in-line with the Stop lamps, so that it is earthed via the Stop Lamp.
As the saying goes, 'not rocket science'.

*it might possibly be configured so that it would tell you if 1 of the 2 lamps was faulty, but that's beyond the traditional vintage/classic that only has a single wire running to the Stop lamps.

[shoebone]

Could I just say ..........Most reproduction brake light switches appear to be made in far away places and can quickly fail, while you're in the area I can recommend the fitting of a relay, this will greatly increase switch life and as a small bonus, with the engine not running I can hear the click of the relay when the brake pedal is depressed. I fitted my relay probably two years ago and so far so good, car is my daily driver. Information regards relay fitment was found through the search function

[Myrtles Man]

Many thanks Shoebone for that heads up. I've now dug out the two issues of Minor Matters that contain the article referred to and will crack on and order a suitable relay.

[neilmorey]

I read some where ages ago that the VW switches were better quality than the Lucas ones for the Minor so I ordered one of these from ECP. Price has doubled in last 5 yrs.

https://www.eurocarparts.com/search/464630010

Used in conjunction with LED bulbs which reduces the current being drawn.

[Myrtles Man]

I've already ordered an 'Intermotor' switch Neil, which, with shoebone's suggestion of a relay (also on its way), will hopefully resolve the issue but thanks anyway for the suggestion.

[Myrtles Man]

Replacement switch and relay now fitted and brake lights working. Thanks everyone.

[shoebone]

Well done, always a good thing when a plan comes together

[JOWETTJAVELIN]

There is a useful Lucas gadget called a Stop Lights Indicator

Sounds interesting, I haven't heard of this before and an internet search doesn't bring it up, do you have a picture or a link to one?
Many thanks,
Mike.

https://www.ebay.co.uk/itm/LUCAS-STOP-L ... SwkjJcTeMI

This is the one I have fitted, but not to my Minor.