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What Temps Do Brake Calipers Run At?
scootz - 12/8/08 at 09:54 AM

I'm looking to give my calipers a little spruce up, and my weapon of choice has always been PJ1 Satin Black engine paint (great stuff!).

It's good for applications up to 500f

Thing is - how hot do calipers run???

BenB - 12/8/08 at 10:00 AM

VHT caliper and drum paint is rated okay up to 900 deg F (accourding to CBS).

Then again, I think quite a few people just use hammerite!!!!

tegwin - 12/8/08 at 10:03 AM

They cant get THAT hot....

Aluminium melts at around 600 celsius....

The rubber boots will proberably melt around 350C.....

So the upper limit of the paint....hmm...your guess is as good as mine

BenB - 12/8/08 at 10:04 AM

http://www.foliatecshop.co.uk/shop/foliatec-brake-caliper-paint-p-80.html

is up to 300C which is 572F
so 500F isn't ridiculously off the mark....

I suppose at the end of the day it depends on your use for the car. If it's a show queen which never moves you could use humbrol enamel

britishtrident - 12/8/08 at 10:07 AM

Very doubtful if they will even see 150c , the discs get pretty hot but not the calipers.

02GF74 - 12/8/08 at 10:36 AM

I would agree with BT.

one way to tell is to buy these:

go up to 410 C doubt they ever will....

the seals would surely fail by then....

smart51 - 12/8/08 at 11:12 AM

They can get hot enough to burn off your finger prints. Ask how I know

They can also get hot enough to boil brake fluid if your heavy footed. What temperature does dot 4 boil at?

Bluemoon - 12/8/08 at 11:15 AM

I think SMART51 as the answer, any hotter and you will not be worrying about the caliper's but what your about to hit..

Quick search on Google:

Dot 4 boils at 230C when new (dry).

http://en.wikipedia.org/wiki/DOT_4


Dan

[Edited on 12/8/08 by Bluemoon]

mr henderson - 12/8/08 at 12:55 PM

quote:
Originally posted by smart51
What temperature does dot 4 boil at?


That would depend on what pressure is exerted on it, greater the pressure, the higher the boiling point

John

scootz - 12/8/08 at 02:57 PM

Cheers!

segan2b - 12/8/08 at 07:54 PM

Mine are painted with Red Oxide Primer and 'High Performance!!' Wilkinsons Exterior Gloss . I had some in and thought I would give it a try .

It's now baked to a very hard tough finish.

v8kid - 13/8/08 at 11:27 AM

The higher the pressure the higher the boiling point?

What about when you take your foot off the pedal - it will boil then!

mr henderson - 13/8/08 at 12:43 PM

quote:
Originally posted by v8kid
The higher the pressure the higher the boiling point?

What about when you take your foot off the pedal - it will boil then!


When you take your foot off the pedal, the pressure goies down and so does the boiling point-

Read all about it here-
http://en.wikipedia.org/wiki/Boiling_point
"
The boiling point of a liquid is the temperature at which the vapor pressure of the liquid equals the environmental pressure surrounding the liquid.[1][2][3][4] A liquid in a vacuum environment has a lower boiling point than when the liquid is at atmospheric pressure. A liquid in a high pressure environment has a higher boiling point than when the liquid is at atmospheric pressure. In other words, the boiling point of liquids varies with and depends upon the surrounding environmental pressure."

John

britishtrident - 13/8/08 at 06:07 PM

Water is brake fluid really brings the boiling point down --- high performance brake fluids ie DOT 5.1 and racing fluids are the worst affected.

Incidentally the the 1920's Stutz black Hawk sports cars had hydraulic brakes which used water with a little added glycerin as the brake fluid -- good enough for a second place behind a 4.5 Blower Bentley at Le Mans in 1928 -- must have been fun at the end of the Mulsanne Straight though.