rear brake cooling solution
10-05-2009, 05:52 PM
#167
Instructor
You might find that the dust shield blocks more of the duct than you think. I too thought it was a minor blockage until I traced the duct on the shield and realized it was blocking perhaps half of the duct. You do need to remove the wheels to get at the shield, but don't need to pull the rotors.
10-05-2009, 06:00 PM
#169
Rennlist Member
Thread Starter
10-05-2009, 06:00 PM
#170
Rennlist Member
Thread Starter
You might find that the dust shield blocks more of the duct than you think. I too thought it was a minor blockage until I traced the duct on the shield and realized it was blocking perhaps half of the duct. You do need to remove the wheels to get at the shield, but don't need to pull the rotors.
and then break out the dremmel ...
10-05-2009, 06:04 PM
#171
Rennlist Member
Thread Starter
It really was so easy to do, once you have the car on the ramp all you need
do is put the bracket over the control arm (there are actually two little shark
fin-like tags on the top of the arm) the hard part is slotting the tabs on the
front of the bracket into the duct, all you do is tilt the bracket forward and
slot those in, then you just press the rear tabs in and pop the M6x10mm
bolts in and screw them tight ...
If you wanted to cut the dust shield I would outline the shield with a sharpie
or similar marker, pull the ducts, take the wheel off and dremmel the
dust plates from behind ... being careful NOT to touch the innner surface of
the rotors with the cutting tool (especially if they are PCCBs) ....
maybe I'll cut the shields and take some piccies ...
10-05-2009, 06:11 PM
#172
Instructor
You have the process right. Put something hard between the shield and the rotor just in case you slip. A scrap of plywood or even last month's copy of Excellence Magazine would work.
10-05-2009, 06:13 PM
#173
Rennlist Member
Thread Starter
exactly what I was thinking, better that than scoring an expensive rotor!!!
it's a real shame that those dust shields are not removable without pulling the caliper and rotor ...
it's a real shame that those dust shields are not removable without pulling the caliper and rotor ...
10-05-2009, 06:23 PM
#175
Rennlist Member
Thread Starter
wheels at the weekend and post some DIY piccies for posterity!
10-06-2009, 06:50 AM
#176
Racer
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10-06-2009, 07:37 AM
#177
Banned
No. The RS basically has the same split lower control arms on the rear as well as on the front (the regular GT3 just has them on front). These split arms allow the use of shims for additional camber adjustment. Anyway, the rear MK2 GT3 brake ducts attach at approximately just forward of the middle of the control arm, which is far away from the "split" area where the shims go.
Edit: Plus what he said ^
Last edited by 340Elise; 10-06-2009 at 08:01 AM.
10-06-2009, 07:59 AM
#178
Banned
I converted my stock GT3 brakes to the PCCB's and never had an issue with the caliper bolt threads then. Since then I have removed them maybe 4 or 5 times without issue for different reasons (usually suspension upgrades, rotor inspection, or brake pad changes).
Anyway, I ended up removing the entire dust shield since I figured it would help with the overall cooling of the rotors. However, I never thought they were dust shields until you guys just mentioned it; I thought they were heat shields to protect any of the rubber suspension parts (I hardly have any rubber left at this point with my new parts) from when the rotors get hot from track conditions.
If you guys want, I would be happy to show you pics of my removed heat/dust shields. I also need to take the rear wheels off today or tomorrow anyway, and I would not mind removing the caliper and rotor on one side to show how the shields are attached and if you could possibly remove them without the brake removal.
Don't you have to remove the rear brake calipers to change the pads? You don't on the fronts, but on the rears I don't see any other way. And all you crazy track guys must be changing pads often, especially for the rears before we got these fancy new cooling ducts!
Let me know on the pics.
10-06-2009, 08:12 AM
#179
Banned
I decided not to cut the dust shields, as that would have required me to jack the car and take the
rear wheels off, from what I could see the shield does not significantly impair the air flow from the
ducts ...
maybe next time I change my wheels/tires I'll whip the dremmel out!
rear wheels off, from what I could see the shield does not significantly impair the air flow from the
ducts ...
maybe next time I change my wheels/tires I'll whip the dremmel out!
10-06-2009, 08:15 AM
#180
Banned
The reason you must replace the caliper bolts each and every time is because they are stretch bolts.
When you torque them they stretch and this changes the thread pitch.When you try to re-use them they have a slightly different thread pitch which is not compatible with the original thread pitch inside the caliper.
Since the calipers are of a softer material the reused steel bolts try to tap a different thread pitch thus leaving you with stripped out caliper.
Just change or replace the bolts each time and you should have no issues.Using a thread lubricant will also change the torque specs and either should be avoided or factored into the torque specification depending on the nature of the lubricant used.
Tom B.
When you torque them they stretch and this changes the thread pitch.When you try to re-use them they have a slightly different thread pitch which is not compatible with the original thread pitch inside the caliper.
Since the calipers are of a softer material the reused steel bolts try to tap a different thread pitch thus leaving you with stripped out caliper.
Just change or replace the bolts each time and you should have no issues.Using a thread lubricant will also change the torque specs and either should be avoided or factored into the torque specification depending on the nature of the lubricant used.
Tom B.
Note to self: Get a clue. Also, get 4 new caliper bolts!