Brake pads.

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Re: Brake pads.

Postby Charlescrown » Wed Jan 12, 2022 3:54 pm

Those shims are supposed to reduce/eliminate squeal but I'm afraid some engineers think all cars need them.

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Re: Brake pads.

Postby vlad01 » Wed Jan 12, 2022 5:57 pm

Those shims were never an issue when they were just a steel free floating shim but once they started rubberizing them and gluing them these issues showed up.

I thought I was crazy having worse brakes on the red VP vs the VR but now I know why.
I'm the director of VSH (Vlad's Spec Holden), because HSV were doing it ass about.

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Re: Brake pads.

Postby Charlescrown » Thu Jan 13, 2022 2:24 pm

There is a silicon based product that you smear on the pad contact patches to help reduce noises. I'm surprised that it caused a problem.

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Re: Brake pads.

Postby vlad01 » Thu Jan 13, 2022 3:10 pm

I asked my mechanic about this and he confirms the same issue.
I'm the director of VSH (Vlad's Spec Holden), because HSV were doing it ass about.

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Re: Brake pads.

Postby immortality » Thu Jan 13, 2022 3:21 pm

Interesting. I'm sure the pads in the Calais have some sort of rubber backing on the shims. Might have to scrape it off and see what happens?

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Re: Brake pads.

Postby vlad01 » Thu Jan 13, 2022 3:57 pm

I think it's less of an issue on bigger/better modern brakes as they often have very firm pedals with great braking effort for minimal input so it won't be so noticeable and also caliper flex is next to nothing on modern calipers.

With the old girls like VN etc.. there is more pedal travel out of the box, small pads for the force applied and flexible calipers, it all exacerbates the issue.

I actually thought there was something wrong with the rebuilt booster in the red VP as I upgraded to the VH512 as the VR has which amplifies the pedal force more than the stock booster, further exacerbating the sponginess. I will have to remove them at some point but I can't test the car as my brother chucked a spa in the way of the roller door saying it was only for a few days, that was 3 months ago :roll:
I'm the director of VSH (Vlad's Spec Holden), because HSV were doing it ass about.

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Re: Brake pads.

Postby vlad01 » Tue Jan 25, 2022 3:44 pm

Got around to sorting the red car out, these shims moved even more than the other car.

IMG_0170.JPG


IMG_0173.JPG




You can see how much these shims can squish by the bending and depression from the piston.

IMG_0172.JPG


Pedal feel is quite a lot better now, but won't be able to road test the car for a while as my brother has filled in the roller door area with junk and a indoor spa. :roll:
I'm the director of VSH (Vlad's Spec Holden), because HSV were doing it ass about.

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Re: Brake pads.

Postby Charlescrown » Tue Jan 25, 2022 3:53 pm

Im thinking you must ahve lots a movement in the caliper to allow the shim to moove that much. Maybe it's time to look a bit closer at the whole assembly. I know you did a tight arse with the rotors which really are quiet cheap.

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Re: Brake pads.

Postby vlad01 » Tue Jan 25, 2022 4:12 pm

The red car was a full restoration. The movement (flex) is normal for these calipers. I never had this issue before becasue pads for early commodores never had these shims until recent years.

The flex is why it's normal for VB-VS brakes to take 1000-2000km to wear in as they need to wear as a taper to compensate for the flex in the caliper.
I'm the director of VSH (Vlad's Spec Holden), because HSV were doing it ass about.

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Re: Brake pads.

Postby Charlescrown » Wed Jan 26, 2022 8:57 am

The big problem is what you just said caliper flex. Their just to flimsy and I know when Bendix were testing they found the caliper was totally RS after a bit of hard braking. They just physically bend. I don't know what model is the best. I think VL turbo used Corvette calipers which I think are a bolt on swap. I put VT calipers and rotors on my VR and really don't notice any spongy pedal that everyone said I would have.

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