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MG MGA - Can't budge brake light switch

Trying to get the old, failed, switch out but I just can't get it to start unscrewing. I'm using a standard 3/8"ratchet set with a 1" socket (old switch is 1", new one is 7/8").

I don't want to soak it in WD40 for fear of contaminating the brake fluid.

Looking for suggestions - has anyone else run into this problem and found a solution?

- Ken
KR Doris

OK, I now have long extension for the 3/8 ratchet and believe I can apply enough force to eventually break the old switch free, but I need to avoid bending the brake lines as the 5-way fitting is rotating.

Any tips on how to keep that fitting from rotating?

- Ken
KR Doris

Ken
Haven't done the job myself but I believe wedging it with some wood may help.
But I have heard that the replacement switches can sometimes be unreliable, so some take a much simpler option and fit a mechanical switch activated by the pedal
Graham V

Ken

I am with Graham. Leave your failed switch where it is for vintage effect and use a microswitch activated by the brake pedal to switch your brake lights.

Cheers
Dave
Bolney Coupe

KT, you need to wedge something in between the switch and the body/frame: a piece of hard wood or hard plastic may do the trick, or you can try to wedge in a long screwdriver between the connector & hold down bolt (see pic #1). If it still does not move you do have the option of disconnecting all of the lines & removing the connector with switch attached, but that leads to other issues & more work. Last option is to just cut the wires to the switch and install a mechanical switch on the brake pedal, or on the end of the push-rod on the master cylinder; photos #2 & #3.

New replacement hydraulic brake light switches have been problematic; I've replaced mine 3 times in the last 6-7 years or so, but it gets easier every time you do it.

Oh, it looks like I can only attach 2 pics here; I'll post the 3rd one separately.






Nick Kopernik

Here's the third pic:


Nick Kopernik

Ken,
I had the same problem a few years ago when my brake light switch failed.
I used a mole-grip wrench to hold the brake union, wedged against the chassis. I actually turned the switch clockwise a fraction of a turn, just to move the threads, then it unscrewed fairly easily.

I hve actually fitted a mechanical switch with an almost identical bracket clamped to the steering column. Almost identical to Nicks 2nd picture) But, so far, my replacement pressure switch has worked fine for over 3 years and so the mechanical switch is just in reserve.
Cheers
Colyn
Colyn Firth

Looks the same as a midget or Sprite pressure switch and five way.
Use moles and grip them tight to stop rotation.
Fit a, direct replacement, Harley-Davidson switch. Part No’s as per photo.
Alan


Alan Anstead

Tried wood brace with no luck - one more attempt with friend tomorrow.

If that fails I’ll have to take it to expensive pro shop in Hilton Head.
KR Doris

Colin - maybe the mechanical switch route is a better option
KR Doris

Well if you do install a mechanical brake light switch Ken, you can always work on removing the pressure switch at a later date.

Like I said earlier, I went at it the other way round, I fitted the mechanical switch at the same time that I replaced the pressure switch. But the replacement pressure switch has worked flawlessly since I fitted it and so the mechanical one is there in reserve. (I made up a short loom with the two brake switch wires in it which I can quickly attach if (or when!) the pressure switch fails again)

My mechanical switch has a built-in swivel which is perfect for where I mounted it onto the outer casing of the steering column, down by the pedals.

I pop-riveted two jubilee clips to the base plate of the switch which I clamped onto the steering column, I used some very thin rubber around the column to protect the paint on it.

The pull spring on the switch attaches to the brake pedal and I made a clamp to fit to the pedal arm because, for safety reasons, I didn't like the idea of drilling a hole in such a structurally important brake component.

So everything about this switch just clamps into place and so no extra holes are drilled anywhere.

I have attached a couple of pics which show my installation far better than I can describe it.

Cheers
Colyn






Colyn Firth

Alan in Kent wrote:
"Fit a, direct replacement, Harley-Davidson switch. Part No’s as per photo."

I tried one of those four years ago. Aside from being twice the price, it is the same bad internal design as the rest, and it failed just as quick. Installed April 1, 2015, failed June 2, 2015 after 8074 miles, so 8-weeks, 8000 miles, par for the course. Don't wast your money on the Harley Davidson switch. See here:
http://mgaguru.com/mgtech/faulty/ft071.htm#harley

And from the attached picture,
https://mg-cars.org.uk/images/bbs/posts/6_2022022515233229718_6767063332171650771286575800530018_1645884599.jpg
put your blocking stick between the fitting opposite from the nut and the frame center weld ridge to prevent the fitting turning ant[-clockwise when you unscrew the switch.

Barney Gaylord

The picture


Barney Gaylord

Ken,
have you tried scraping and brushing the threads to break any crud seal, I know it's difficult to get at but perhaps modify a cheap plastic brass bristled brush with a junior hacksaw as the modifier.
Nigel Atkins

OK i got it out and now have to resolve a small leak from where I bent the rear brake line too far🤦🏻‍♂️
- Ken
KR Doris

Oops Ken!
does that mean that you have cracked the brake-lines?
Hope it is one of the shorter sections.

Cheers
Colyn
Colyn Firth

Colyn - sigh, the long one going to the rear. Looks like I’ll have to run a new one.
KR Doris

Ken
Bad luck, I believe you can replace the broken section and join it to the good section, but personally I would play it safe and replace the entire line.

Colyn
Couldnt quite tell from your picture; can I ask although it's probably just me being dumb, what does the spring do attached to the micro switch?
Graham V

Ken,
when I was a young lad and not long started going out with my girlfriend, now wife, nearly 45 years ago, we being young both lived with our parents. I, trying to impress, went to repair/replace the pilot light on the hob (pans part) of her parent's freestanding cooker and I nipped up the pipe too much, no worry I'd isolate that part, but it went to the oven and the correct part was on back-order for weeks. They couldn't use the oven and her mother was very much an oven user - and I was already the rough kid from the wrong side of the tracks. Another time the parts would have been a few days at the most. A 'gasfitter' mate who lived just down the road from her parents laughed and said it could have happened to anyone - but it didn't it was me. Took a very long time before I was trusted with "helping" again.
Nigel Atkins

Hard luck Ken,
I'm pretty sure that you can buy the correct length of brake pipe and pre-assembled with all the fittings (probably from Moss), but there will be other options such as Cecelia or VB?

Graham, the switch is designed to pull to make contact and is spring loaded inside to automatically switch off.
So the spring is attached to the brake pedal at one end and the pull switch at the other.
The switch swivels on its base-plate which allows the switch to self-align with the pedal.

So the spring is just a simple and flexible way of connecting the switch to the brake pedal.

I have attached the picture of the switch again which may help to show how it works.

Cheers
Colyn



Colyn Firth

Nigel - I'm glad your pilot light error didn't get you banned forever. Another example of "this should be easy-peasy...oh, CRAP!"

Colyn - just got off the phone with Cecilia - a new pipe and 4-way junction are on the way. I'm replacing the junction as well as it seems pretty beat up at this point so why take chances?

Hoping the rest of this journey actually IS "easy-peasy"

- Ken
KR Doris

Ken
I was just thinking about brake stuff and how, no matter how careful I am, I always seem to spill some brake fluid on the paintwork somewhere.

So I wondered if anyone had any suggestions for cleaning up spilled brake fluid before it removes the paint? ( I know I am now bound to get some "Captain Hindsight" style comments asking why I haven't switched to silicone brake fluid yet! :^)

I hope that Melon is still doing her running, so that she is fit enough for all the pedal pumping she is going to be asked to do when you bleed the brakes. :^)

I did try an Easi-bleed pressurised brake bleeding gadget, but it pumped brake fluid all over the heater shelf and so I ditched it and went back to using a simple bleed tube with a one-way valve, combined with Chris sitting in the car, pumping the brake pedal whilst browsing through Facebook on her Ipad.

Before you begin the job, I would put a piece of thin cellophane screwed down under the brake cylinder filler cap. This will pretty much stop
(or at least slow down) the brake fluid flowing out of the master cylinder and this makes bleeding process much easier.

This could also be a good opportunity to renew all the brake fluid.

Let us know how you are getting on.

Cheers
Colyn


Colyn Firth

Ken,
it all worked out well in the end and water under the bridge, I would like to say I learnt from it but had a period of not tightening enough so nipping up later and then too much but nothing as bad as the pilot.
Nigel Atkins

Colyn,
I ask myself frequently why I haven't switched to silicone especially reading about others use of silicone mixed with standard for years and no disasters or even noticeable.

When flushing/changing the fluids in the brake and clutch (done far too often on my car, don't ask) I use old water-soaked cloths to protect paint work and have a bucket of water to refresh them as I work outside usually in the sun as I want to be warm if I have to work on the car (and I never want to) and I also have a watering can, without spout, full of water in case of accidents.

Really annoys me that in the 21st century we still have things like standard brake fluid that needs changing so frequently and can cause so much damage but it's cheap to produce and plenty of profit from selling it and idiots like me allow themselves to be taken advantage of.
Nigel Atkins

For future reference, you can slip an adjustable wrench over one of the 5-way arms to hold it in place while wrenching on the switch.
Steve Simmons

Colyn

Thanks for the explanation - seems like a good way to set it up
Graham V

Colyn, I didn't mean spout I meant sprinkler end, I also don't do gardening, it's like repair old British cars I can only do it if the weather is right and if the weather is right for either I should be driving the car instead.
Nigel Atkins

Steve - thanks for the tip, I'll try that next time. Seems my attempt to use a wood block against the arm leading to the rear brakes (after crimping the line without it) resulted in cracking that corner of the 4 (5?) way junction.

Colyn - Melon had replaced her morning run with a daily hour long swim in our local High School pool. I'm sure she could still pump the brakes to bleed but I've decided to let a local shop finish the junction & line replacement and save my back and knees for other projects around the house!

Nigel - a few leaks of dot 3 brake fluid ruined the paint on my heater shelf as well - a major reason for the change in 2019 to dot 5. I was warned about a softer pedal but haven't had any negative effects that I can discern in that or braking efficiency.

We've planned an 800 mile round trip to a GOF event in Florida in late April and combining it during that same trip with a visit to Amelia Island (after the Concours) in our MGA.

After that, in June we will take the car to Colorado Springs for the NAMGAR GT and continue over to Boulder CO to visit our daughter and her husband. Assuming all goes well we'll next visit some National Parks in CO and Utah before returning home after about a 4,000 round trip.

Look for some more updates later this year to our website - www.mga-mk2.com

- Ken
KR Doris

Ken,
My brake lights were getting very dim so I decided to install a mechanical brake light switch. I fabricated a bracket from aluminum angle iron, painted it black and installed it. Works pretty well. I bought a switch from Moss that’s for a TR6 (Moss part #542-371) https://mossmotors.com/brake-light-switch-adjustable-upgrade

Jim





JL Cheatham

When Jim has converted his MGA to use a mechanical brake light switch, I take that as a sign that all hope of ever getting an original type replacement hydraulic switch that doesn't suck, is lost.

-Del
D Rawlins

When my brake switch stopped working I decided to fit a mechanical switch similar to Jim's but mine is made of pressed steel. I fitted an adjustable off/on switch so that the brake light comes on a lot earlier than the old one, making it safer for approaching cars to see me. Totally reversible.





Brian Paddon

Very neat job Brian! My new switch is in and working fine. We'll have to see how long it lasts :~)
KR Doris

This thread was discussed between 25/02/2022 and 21/03/2022

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