TR2/3/3A Brake Lamp

[DavidApp]

Ordered a switch from Summit Racing Part number PRF-80172 $15.00
Made my bracket and everything is installed.
Hopefully one more problem headed off.

I plan to use DOT5 as that is what I used when I rebuilt the front brake calipers. The system is completely empty and clean. A counter gyu at a non big box parts counter said "Why DOT5". Said they hardly sell any DOT5.

David

 

[TR3driver]

I'm surprised you even found DOT 5 at a local store. But if they ask again, you could show them this photo

I also saw a very graphic demonstration some years back at TRfest. Fellow with a very nicely restored TR4 had just unloaded it from the trailer, and discovered he had no brakes. When he opened the hood to check, the paint under the brake MC and all down the firewall was already starting to wrinkle and bubble up!

 

[Geo Hahn]

...A counter gyu at a non big box parts counter said "Why DOT5". Said they hardly sell any DOT5...

He could also ask 'Why a TR3?' and add that they hardly sell any Triumph parts.

My local doesn't carry DOT5 either so they certainly don't sell much. Probably not enough demand plus it would only confuse the buying public.

 

[DavidApp]

Was that the result of DOT5 or DOT3/DOT4?

David

I'm surprised you even found DOT 5 at a local store. But if they ask again, you could show them this photo

I also saw a very graphic demonstration some years back at TRfest. Fellow with a very nicely restored TR4 had just unloaded it from the trailer, and discovered he had no brakes. When he opened the hood to check, the paint under the brake MC and all down the firewall was already starting to wrinkle and bubble up!

 

[DavidApp]

Very true. I did not confuse him with the TR3 bit just asked for a brake light switch and explained the type I was looking for. It was then we got to the DOT5 bit.

I got the can I am using from a local Automotive big box store.

David

He could also ask 'Why a TR3?' and add that they hardly sell any Triumph parts.

My local doesn't carry DOT5 either so they certainly don't sell much. Probably not enough demand plus it would only confuse the buying public.

 

[Got_All_4]

I started out with DOT5 in my TR250 restoration and it's been in there since 2004 20k miles and never had a brake light switch frailer. Now tomorrow I'll go out and not have any brake lights. Just went on a 600+ mile trip in the TR3 with my set up I showed earlier with no problems.

 

[TR3driver]

Was that the result of DOT5 or DOT3/DOT4?

David

DOT 3.

All the glycol-based fluids (DOT 3, 4, 5.1) absorb moisture not only from the air, but right through brake hoses as well (according to an old presentation to the SAE). Over time, they become corrosive and lead to the sort of damage shown above.

I don't have a photo, but I once made the mistake of filling a pair of brand new rear brake cylinders with Castrol LMA (DOT 4), sealing the ports and putting them back on the shelf. Wound up not using them right away; when I did finally get the box back down, the cylinders were totally ruined by corrosion!

DOT 5 by contrast acts as a preservative and prevents corrosion.

 

[DavidApp]

Hello Randall

Thank you for that info.

That is what I said to the parts guy.
I gather DOT5 is not so good for systems that have valves that require lubrication.

David