Brake Pressure - Brembos

[wierz11]

Looks like those are 2-piece ones, and according to Brembo they are 355mm. They are quite expensive. Here is your replacement set. Unfortunately, those are just the discs, and the Astra J VXR is 5x115 bolt pattern. It would be easier finding a BMW set that has 5x120.

But it would just be silly to spend that on 2-pc brakes. Just buy a set of black drilled rotors for the front and back 😛

 

[nizerims]

Yowzers, $15hundo for 2 disks! (plus S&H) NEXT

Probably going to take off the fronts to take a closer look and do some measurements (if I get time) this weekend. I hope the front rotors aren't rusted to the hub as bad as the rear rotors were.

Thanks for that link tho.

 

[MayorMcCheese]

Niz any update on this ?

 

[GRRR8GS]

The same rotors as our Regal GS are on 2009 Pontiac G8 GXP's so DBA out of Aus. makes them also. Maryland Speed can order them but they are pricey at around $200 each. Hard to beat those nice black ones at BP.

 

[MayorMcCheese]

What i cant figure out is i changed my brake pads on tuesday , and theyve been doing great but today i decided to hit the brake pedal and when i did 3/4 of the way the pedal just got weak and went to the floor very easy , than i get home and my left rotor is smoking ..

the ****? I didnt bleed the brakes but I do wonder if installing my boost gauge and using the vacuum line has anything to do this this

gonna get some amsoil Dot 4 brake fluid but how much do you need to bleed the brakes?

 

[Walt G]

Sounds to me like you were the second one on these forums to boil the brake fluid in a Brembo caliper, except yours sounds like it is due to something being stuck, not driving it too hard on a road course.

Although the brake fluid probably has some water content and a lower boiling point than new, these brakes should not be smoking hot. Even driving on a road course (hard) mine were not smoking. Something is causing your brake to stick on. You need to solve that problem.

Generally when you screw up your vacuum assist system the pedal gets firm and just requires a ton of effort to slow the car down. It doesn't sound like you have a vacuum assist problem from your description (pedal went to the floor very easy). And a vacuum problem wouldn't fix itself, so if the brakes feel normal again after cooling down, it was a brake fluid boil issue.

I've had brake pads in the past not fit right and get 'jammed' in the caliper. That's the first place I'd look.

Hope that helps.

 

[MayorMcCheese]

dont think it was smoke , i checked the car just before (check my new thread) and there cool , when i hit the brake pedal its like a water spritz

so until monday i am taking it easy and i now have to hide the CEL from underboost by reflashing the ECU lol

 

[IndyGS]

Although the brake fluid probably has some water content and a lower boiling point than new, these brakes should not be smoking hot. Even driving on a road course (hard) mine were not smoking.

When I was doing research on how to bed my new pads, pretty much all instructions I could find said to repeat the 60mph to slow roll sequence a number of times, and that smoke (and even some temporary FLAMES) could be expected during that process. Are you saying that brakes should not be smoking hot under normal driving conditions? Or are you saying that they should never be allowed to get smoking hot, period. Just want to make sure I didn't screw anything up during the bedding process. I haven't noticed any brake fade, or any other problems at all for that matter.

 

[Walt G]

The day I ran my Regal at the local road course, I noticed some cars with smoke billowing from all four corners at the end of the runs, and the very strong small of burning brakes. All I meant was that mine never did that even after 10 minutes of extremely hard driving, so I didn't think his should do that after just one stop, no matter what.

Some smoke during bedding seems normal, as you have described.

On a note more related to the original topic of brake feel, I was looking through my Regal service manual today, and there is actually a specification for this (brake pedal firmness). It says to measure the distance from the steering wheel to the brake pedal, and then apply 100 lbs of force to the pedal and the pedal should move between 48 and 58mm. This is done with the engine off and after pumping the brakes a few times to deplete the vacuum booster reserve, so I guess it doesn't tell you if you've got a brake booster problem.

Something to try though if anyone else feels that their brakes don't have the right 'feel', like the OP.