Brake light switch removal

[MoggyTech]

I'd go for a slightly higher current rated switch:

2 x 21W bulb / 12V = 3.5A


mind you, the most feeble microswitch would probably last longer than the rubbish hydraulic switches I've had recently!

A switch that will handle 2.5A at 250V AC rating will handle much more than 3.5A at 14.5 Volts DC It is safe to double the AC rating for DC use as long as it's not switching an inductive load like a heavy motor.

[Alec]

Hell all,

one car that uses a switch activated by the brake pedal is the Triumph 2000 range and obviously is suitable for vehicle use. It is attached with a nut, you just need a bracket with a hole to mount it.

There is no need to re-invent the wheel by cutting ring spanners, there are spanners available for that specific task and usually are known as 'flare spanners'

Alec

[sixdogs]

I had not realised that Mole Grips is a brand name. I've been using them since at least the early 60's when I was at school, so they have been around for a long time. I suppose it's a bit like the name Hoover. By the way, it's getting hard to buy a decent pair these days, does anyone know a reliable source for a good quality pair ?

I'm still interested in the idea of a micro switch, but I think I've now resigned myself to removing the brake pipes from the 4 way block, as it's safer than risking wrecking the pipes I wanted to avoid bleeding the brakes as I have silicon fluid in the system and apart from the cost of having to buy a litre, I'm not sure which brand is in my car, or the compatibility of different brands. Does anyone have any kowledge of this ?

I think the pipes will come off easily, as they are recently fitted copper pipe, which the previous owner had fitted, not very long ago. I might just as well fit a new 4 way, unless anyone thinks the new ones are not very good.

Thanks for the input, Clive.

[MoggyTech]

Silicon brake fluid use is farely rare, and as far as I know, there is only one DOT spec so you should be ok as long as the fluid has a DOT specification, and is of course Silicon.

I assume by copper brake lines, you mean proper Kunifer type? Anti corrosion brake lines often get called 'copper' yet copper on it's own is useless for brake pipe, as it work hardens with vibration and fractures.

A new 4 way piece will depend on what line end fittings the previous owner fitted. Some are metric others are BSF or UNF. I would take the old 4 way to a motor factors along with your new switch, and have them check the threading used. My motor factor no longer stocks anything but metric brake fittings, so I have to order new fittings from ESM or Bull Motif.

Now you know why that Microswitch mod is the way to go

[sixdogs]

AC switches often struggle with DC current - better use a switch that is rated for DC use.

Yes that is correct. Also, the rating of the switch needs to be several times that of the steady 3.5 amperes that the 21 watt bulbs draw. When you first switch on an incandescent lamp, the filiment represents almost a short circuit when it is cold. The current can be many times that of the hot state momentarily. So the switch needs to be able to stand the surge.

I've just looked at the pedal on my Mercedes 308D truck and it has a fine looking micro switch mounted above the pedal. Mine is 1993 and has done 200k miles, so they are good switches. Should be plenty in scrap yards by now!!

Regards.

[sixdogs]

[quote="MoggyTech"]

I assume by copper brake lines, you mean proper Kunifer type? Anti corrosion brake lines often get called 'copper' yet copper on it's own is useless for brake pipe, as it work hardens with vibration and fractures.

quote]

Yes, the pipes are the propper ones as you would get from Bull Motif ets. I think I will take the old 4 way to Minor Developments, which is just a few miles up the road, to check the threads etc.

[Alec]

Hello Moggy tech,

"copper on it's own is useless for brake pipe,",

Well Automec have been selling pure copper brake lines for a very long time, and I have used their products (including silicone brake fluid which they say is compatible with glycol fluids also) on several cars , also for a very long time. (20+ years) and have not had a problem.

They recommend more clipping than steel, but the pipe is thick walled and specifically sold as brake line pipe. That and the use of brass fittings means that you can confidently undo lines confident that they are unlikely to twist and shear as the old steel lines did.

Alec

[MoggyTech]

Hi Alec,

Are you sure those pipes are pure copper and not 90-10 Copper-Nickel ?

[Alec]

Hello Moggytech,

"pure copper brake lines", yes (and as I once worked in a copper mine, there is no such thing as commercial pure copper) 99.99% copper.
have a look on their web site, www.automec.co.uk

Alec

[MoggyTech]

Hello Moggytech,

"pure copper brake lines", yes (and as I once worked in a copper mine, there is no such thing as commercial pure copper) 99.99% copper.
have a look on their web site, www.automec.co.uk

Alec

Hi Alec,

Checked out their web site thanks. So are we to assume that the things said about 99.99% copper brake lines are just 'hype' or 'folk lore' perhaps to premote stuff like Kunifer? I did notice on the Bundy Lines site, they even say Kunifer is not really safe, at least for racing applications. As for copper only brake lines, they do say it's a no no. However, if you have been using copper lines for 20 years with no problems, I guess it's just another 'urban myth'. Someone call Adam & Jamie aka The Mythbusters.

[Alec]

Hello Moggytech,

I certainly understand the point you made, but in engineering there are ways to offset weaknesses in materials. In other words, specify adequate margins that compensate whilst using the benefits that that material may have.

Alec

[Roni]

Another idea for a brake light switch - a motorcycle rear brake light switch. It operates by pulling, via a spring from the brake pedal, so setting up should be easier. Some come with an adjustable threadded mounting too.

[RogerRust]

Sorry to go off topic, but can anyone telll me why they called the "Mole" grip - Do moles have very strong grips, or jaws that lock?
Come on you paintshop experts do your stuff.

[Orkney]

Think the original design was made by a company called 'Mole' so they got branded as such - bit like people calling a dyson a hoover

[RogerRust]

Oh, now you have spoilt it!

[millerman]

And envelopes from Newport S Wales used to be franked
'Newport - Home of the Mole'

[DaveC]

PS: I never realised mole-grip was a trade name, I thought that's what they were called!

My Aunt went into Kent Blaxill in Colchester to buy me some for my 13th birthday in 1973. She asked for 'Badger Clamps' but they knew what she meant