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  Soarer Central * Brakes * Calliper piston uneven pressure mark on shim. Previous Previous    Next Next  

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Juan Landauro
Newbie
bolton
3.0L 6-line

Posts: 5
Reg: 11-2006

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Saturday, November 18, 2006 - 08:04 pm, by:  Juan Landauro (Enigma) Quote hilighted text Edit Post Delete Post Print Post   View Post/Check IP (Moderator/Admin Only) Move Post (Moderator/Admin Only)

When I took the brake pads from the front calliper I noted that the mark left by the calliper piston on the pad shim was 2/3 of a circle and the other 1/3 of the circle just fades away. It appears that the piston pressure when the brake pedal is depressed doesn’t catch the whole of the brake shim, perhaps because the brake pad or the calliper assembly are not parallel anymore. What could cause this behaviour? What should I do in order to put it right? Shouldn’t I bother about it?
Mark Paddick
Goo Roo
ACT
UZZ31 V8 Soarer , JZZ30 TT Soarer

Posts: 2880
Reg: 07-2005

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Sunday, November 19, 2006 - 12:22 am, by:  Mark Paddick (Sparks) Quote hilighted text Edit Post Delete Post Print Post   View Post/Check IP (Moderator/Admin Only) Move Post (Moderator/Admin Only)

Sliding calipers. The slide pins are worn, bent or otherwise rooted.
This is the best argument for 4 pot non-sliding calipers.
Juan Landauro
Tinkerer
bolton
3.0L 6-line

Posts: 9
Reg: 11-2006

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Monday, November 20, 2006 - 07:45 pm, by:  Juan Landauro (Enigma) Quote hilighted text Edit Post Delete Post Print Post   View Post/Check IP (Moderator/Admin Only) Move Post (Moderator/Admin Only)

Hi Mark:

I am a bit confused I though the piston push the internal brake shoes and the floating system calliper react by pulling in the outside brake pad by operating the sliding pins.
Mark Paddick
Goo Roo
ACT
UZZ31 V8 Soarer , JZZ30 TT Soarer

Posts: 2901
Reg: 07-2005

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Monday, November 20, 2006 - 08:51 pm, by:  Mark Paddick (Sparks) Quote hilighted text Edit Post Delete Post Print Post   View Post/Check IP (Moderator/Admin Only) Move Post (Moderator/Admin Only)

That's right, and when the slides or pistons get worn the slide is no longer square to the disc and this results in uneven pressures on the pads and hence the shims have uneven wear marks on them.

Without a doubt, sliding calipers are THE worst feature of the Soarer. Such a nice well-designed car with cheap-arsed brakes. Great when new but as any old Valiant owner will tell you they are the absolute pits when older.
Dan McColl
Goo Roo
Victoria
Bog Standard Active

Posts: 1551
Reg: 07-2005

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Friday, November 24, 2006 - 10:29 pm, by:  Dan McColl (Hoon) Quote hilighted text Edit Post Delete Post Print Post   View Post/Check IP (Moderator/Admin Only) Move Post (Moderator/Admin Only)

Would you stop comparing this fine masterpiece of Jap engineering with a cranky old valiant...
Juan Landauro
Tinkerer
bolton
3.0L 6-line

Posts: 15
Reg: 11-2006

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Monday, December 11, 2006 - 01:20 am, by:  Juan Landauro (Enigma) Quote hilighted text Edit Post Delete Post Print Post   View Post/Check IP (Moderator/Admin Only) Move Post (Moderator/Admin Only)

Could be the calliper flex that is causing this problem other than the calliper pins or pin road?

Do somebody know what is calliper flex. Is this a problem of calliper design?
Mark Paddick
Goo Roo
ACT
UZZ31 V8 Soarer , JZZ30 TT Soarer , UZZ32 Soarer

Posts: 3325
Reg: 07-2005

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Monday, December 11, 2006 - 12:32 pm, by:  Mark Paddick (Sparks) Quote hilighted text Edit Post Delete Post Print Post   View Post/Check IP (Moderator/Admin Only) Move Post (Moderator/Admin Only)

Yes, with callipers using sliding pins like these.
Also actual flex of the caliper housing and distortion of the piston/bore but that only happens with very large brake applications and should not be happening on the street even with 15yo totally stuffed calipers, serious Race cars only and I do mean serious. Formula one cars have this problem especially as the pads wear and pistons have lnger travel.
It is possible that badly built or designed calipers could do it badly but not out of Japan and not in the last 30 years or so with metallurgy that was available then and has only improved since. The Japs are up there with if not THE best in that field.
The 4 pot design of Supra and Celsior later calipers gets away from pin flex and wear and clearance problems completely.
I cannot believe they used the sliding design on a prestige car like a Soarer when 4 pot technology costs not that much more in the factory and they used it elsewhere. It's one of the anomalies in design of an otherwise excellent car. There are a few. Nothings' perfect in all respects.
And easily fixed.

I don't compare 40 series Soarers to Valiants except in looks They got 4 spot brakes and bloody good ones, but look like an AP5 on steroids. Matters not at all after you drive one; it looks great no matter what!
Brian Timms
Tinkerer
New South Wales
180sx DET

Posts: 18
Reg: 12-2006

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Tuesday, January 02, 2007 - 03:27 pm, by:  Brian Timms (Turbo_brian) Quote hilighted text Edit Post Delete Post Print Post   View Post/Check IP (Moderator/Admin Only) Move Post (Moderator/Admin Only)

Are the 4 Pot Supra callipers and brakes a direct swap-over for the Soarer brakes, if they are, this is a stupidly easy upgrade.

B.
Don Bagnall
Moderator
New Zealand
I have WAY less Soarers than Hayden :-(

Posts: 5339
Reg: 05-2005

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Tuesday, January 02, 2007 - 03:47 pm, by:  Don Bagnall (Baggs) Quote hilighted text Edit Post Delete Post Print Post   View Post/Check IP (Moderator/Admin Only) Move Post (Moderator/Admin Only)

The problem is NOT with the brake swap, it's having rims that'll clear the calipers, which can make for a bit of a budget blow-out unless factored in

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