Astra H VXR Sprint

Recently Pagid DOT 5.1 has been the preferred choice of brake fluid. A respected name in braking systems, the fluid is relatively inexpensive (compared to many) and has a Dry Boiling Point of 269 degrees C and a Wet Boiling Point of 184 degrees C. With the good brake cooling that the car has fitted the DOT 5.1 fluid has been excellent in service, offers an excellent pedal and has never caused any issues and never suffer from heat.

After some further research a couple of fluids from ATE were picked up on the radar; SL6 and TYP200.

ATE SL6 is specifically designed for cars with ESP and ABS due to its low viscosity and whilst it is a DOT 4 fluid has a Minimum Dry Boiling Point of 265 degrees C and a Minimum Wet Boiling Point of 175 degrees C. More than ideal for road use.

ATE TYP200 is again a DOT 4 fluid with a higher viscosity than ATE SL6 of  but capable of operating at high temperatures. A Minimum Dry Boiling Point of 285 degrees C and a Minimum Wet Boiling Point of 198 degrees C.

The minimum Dry Boiling Point for a DOT 4 fluid is 230 degrees C, and Wet Boiling Point is 155. For a DOT 5.1 fluid the minimum temperatures are 260 degrees C Dry and 185 Wet.

ATE TYP200 way exceeds the minimum benchmark for a DOT 4 fluid and also exceeds DOT 5.1 temperatures, so will be the brake fluid used come the next fluid change.

Both types are supplied in metal 1L containers meaning if sealed and unopened have a shelf life of up to 5 years.

ATE SL6 and TYP200 Brake Fluid

Prior to this season’s trackdays it was time to check over the rear brakes as on visual inspection the pads looked a little low.

Rear pads are not expensive at under £25 a set, so it made sense to replace them as they were about 60% worn. Having covered 4,000 miles, they certainly wouldn’t last the coming 2016 season.

New set of Pagid pads:

Pagid Rear Pad Set

After a little over 2,000 miles the first set of RS29’s are now somewhat past their best and with a track evening coming up a new set are in order. Upon visual inspection there appeared to be just about enough ‘meat’ left on them for an evening track session, but upon closer inspection it was much more obvious that they were in need of replacement.

So a new set of RS29s for the Alcon 4 pot calipers, ready to go in. The top and bottom edges were chamfered prior to fitting as they were being used with the existing discs which are still in very good condition:

Pagid RS29 Brake Pads

Replacing these ones which have certainly been put to work!

A well used set of RS29s

Much better now, good for another track season. They just need bedding in now, following the suggested Pagid bedding-in procedure:

Pads Fitted

And when the pads were fitted Cera Tec was used where required in place of the usually chosen copperslip, mainly due to its high heat resistance. Cera Tec is a metal-free high temperature resistant (up to 1000° C) anti-squeal lubricant for braking systems. Easier to apply and much less messy than the alternatives!

Advantages of Cera Tec

• non-conductive contains no solid constituents
• anti-lock approved
• facilitates brake assembly
• reduces brake squealing protects against scratching and corrosion
• free of copper (0% copper content) and acids

The car came fitted with Alcon Monobloc 4 Pot calipers with single piece 345mm EBC discs. The discs are somewhat past their sell by date, as can be seen from the picture! Badly lipped and the grooves have been completely worn away.

Original One Piece 345mm Disc with Alcon Caliper

I decided that since the discs need replacing and that to fit the 345mm single piece discs the original brackets had been turned upside down and spaced out with washers (which I felt was not be ideal for track use left alone road use!) something different is called for.

So instead of using the Alcon 343mm discs and bells I will switch to a 356mm disc and alloy bell set up which would need a new single piece calliper mounting bracket. So to have the calliper mounting brackets machined, a piece of T6082 material is required:

T6082 Aluminium

Once the calliper was mocked up onto the new discs using the original brackets and some spacers to allow accurate calculation of dimensions:

Alcon Caliper and 356mm Disc

the new aluminium brackets were CNC machined:

Brake Caliper Mounting Brackets

New Bracket (bottom) with Original Bracket (top)

Brake Caliper Mounting Brackets

New Caliper Bracket:

Aluminium Caliper Mounting Bracket

New Bracket Trial Fitted to hub:

Bracket Mock Up

356mm disc and bell added:

Alcon Caliper and 356mm Disc

And all fitted, with a lovely brand new set of Pagid RS29 pads:

All Fitted