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Rich B
Alfa 33
Joined: 19 May 2003
Posts: 386
Location: Southampton
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 Posted: Fri Jan 06, 2006 1:01 am Post subject: Brake fade |
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Hello all
I've been experiencing brake fade during hard road use and wondered what I can do to reduce it.
I'm running with standard size vented Tarox G88 40 groove discs on the front and solid rear discs with Tarox fast road pads all round and braided hoses. Initially braking is very good but after a while they fade really badly.
I presume the problem is heat - I've got P4 alloys which might not dissipate the heat as well as a more open design, and I was thinking that maybe the dust sheild/back plate of the discs could be preventing heat from escaping.
Is there anything I can do that would help, or do I need to fit larger discs?
Thanks |
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Bellamachinna
Alfa 33
Joined: 12 May 2003
Posts: 352
Location: Lisbon-Portugal
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| Posted: Fri Jan 06, 2006 5:05 pm Post subject: |
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Hi... 
What brake fluid do you use?? Did you changed it recently?
Also, what pads do you use?
These itens can reduce fade resistance very much...
If you use the standard DOT4 fluid, improve it to DOT 5.1. Change it as soon as it gets darker in the reservoir, or at least once a year...
Also the pads are very variable in their composition...
On my 16v, i fitted a set of Ferodo pads... Amainzingly, these were worse, than the previous Textar pads that they replaced...After 2 or 3 hard braking ( from 160 Km/h to 30 km/h ) the pedal feel detiorated and i only feel it "bite" with the pedal almost on the carpet...
After "donwgrading" back to Textar, it improved a lot...
My car runs a standard set up...
Hope this helps
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Rich B
Alfa 33
Joined: 19 May 2003
Posts: 386
Location: Southampton
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| Posted: Sat Jan 07, 2006 7:47 am Post subject: |
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thanks for the tips Bellamachinna,
I'm using dot 5.1 brake fluid although it hasn't been changed for a while (it looks ok though). I'll try changing it, but I'm pretty sure that the brakes faded when the fluid was changed before.
I'm using Tarox fast road brake pads front and rear - they give good braking power to start with, then I experience brake fade. I have used Ferodo DS3000 brake pads in the past and they were incredible but the brake dust seemed to be very difficult to clean from the wheels and if left for more than a week was almost impossible to shift. I didn't experience brake fade with them, but I didn't go on racetracks when they were fitted! I would try them again, but the brakedust ruined my wheels. |
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Ben_nz
Gold Cloverleaf
Joined: 30 Sep 2003
Posts: 575
Location: Auckland, New Zealand
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| Posted: Sat Jan 07, 2006 11:33 pm Post subject: |
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"All brake fluid, apart from silicone fluids, are hygroscopic which means that
they will absorb moisture. The higher the DOT rating, the less
hygroscopic they are. In other words, the less moisture they will absorb over a given period. Over time this
will contribute to a brake fluid's 'wet boiling point'. Using a high DOT rating in a road car theoretically
means that you will not have to change your fluid as often as you would if you were using a lower DOT
rated fluid. This however does not apply to a race car as a race cars brake system produces so much
moisture and debris that the road car laws of longevity are not really relevant." |
As I understand it you want a race brake fluid which is less compressable and has a higher boiling point, the downside being you'll need to change it more often(?). And you need the right pad compound with a high coefficient of friction which doesn't decrease much as its temperature rises. The brake company that equip many of the cars in NZ's largest tarmac rally reckon the way to go is "inexpensively speccing up your existing
road brake system with proper race compounds and fluids. This does not mean using road oriented metallic
or kevlar pads or 'DOT 5' fluid. Although these will be better than a set of standard cardboard pads, they
really should not be let anywhere near a race car or track".
Apparently it's possible to "...set up your existing brake
system to a point where we can guarantee that you will not outdrive your brakes on the road or on the track" by just upgrading front and rear pads and brake fluid, if you use the right stuff. |
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Admin
Site Admin
Joined: 19 Feb 2003
Posts: 1223
Location: Stafford, UK
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| Posted: Sun Jan 08, 2006 4:32 pm Post subject: |
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Hi
DOT 5 fluid does not have a great reputation for pedal travel. Compared to DOT 3 / DOT 4 / DOT 5.1 it is more compressable.
On the other hand it does not absorb water (good and bad points) and it does not wreck paint.
All the best
Keith |
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tvatavuk
Gold Cloverleaf
Joined: 13 Mar 2003
Posts: 673
Location: Split, Croatia
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| Posted: Mon Jan 09, 2006 12:10 pm Post subject: |
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DOT 5 is silicon based, not compatible with any other 3/4/5.1 brake fluid.
,has lower boiling point then 5.1 and usualy not compatible with many ABS newer sistems out there.
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Tino Vatavuk
Little black dress which replaced Alfa Romeo 33 S 16v Permanent 4 GMo |
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