Rear brakes

Talk about the E-Type Series 1

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alunwill
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#1 Rear brakes

Post by alunwill » Sat Jun 14, 2025 7:04 pm

I had a quick look at the pistons on my rear brakes earlier today. Three of the 4 pistons were well corroded, so it looks as though it's replacements for all.

I read on the forum that some members have used the front 2-1/8 on the rear when they've uprated the fronts to 4 pots because it brings front/rear balance closer to design.

As I need to buy new for the rear, is it advisable to go 2-1/8 or stick with the standard size.

I've have zeus 4 pots for the front.

Advise would be appreciated.


Alun
Al

Series 1, 2+2
undergoing renovation

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abowie
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#2 Re: Rear brakes

Post by abowie » Sun Jun 15, 2025 12:00 am

Have a look at these https://mossmotors.com/8777-2-cp-cobalt ... t_products

WRT balance calculate your front caliper total piston area, then see which of the available sizes gets you closest.

The stock calipers have 60% front bias.
Andrew.
881824, 1E21538. 889457. 1961 4.3l Mk2. 1975 XJS. 1962 MGB. 1979 MGB.
http://www.projectetype.com/index.php/the-blog.html
Adelaide, Australia

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angelw
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#3 Re: Rear brakes

Post by angelw » Sun Jun 15, 2025 1:09 am

Alum Wrote:
I read on the forum that some members have used the front 2-1/8 on the rear when they've uprated the fronts to 4 pots because it brings front/rear balance closer to design.
Hello Alum,
I can't see that at all working. The rear brake caliper incorporates the Hand Brake mount, which is not included on the front brake caliper.

Regards,
Bill

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abowie
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#4 Re: Rear brakes

Post by abowie » Sun Jun 15, 2025 6:01 am

angelw wrote:
Sun Jun 15, 2025 1:09 am

I can't see that at all working.
It does. You just put the 2 1/8" cylinders on the rear caliper body.
Andrew.
881824, 1E21538. 889457. 1961 4.3l Mk2. 1975 XJS. 1962 MGB. 1979 MGB.
http://www.projectetype.com/index.php/the-blog.html
Adelaide, Australia

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alunwill
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#5 Re: Rear brakes

Post by alunwill » Sun Jun 15, 2025 3:54 pm

Hi Bill,

Yes it should work. I've checked the cylinders and the fronts (2-1/8) do physically fit the rear. Awaiting information from zeus about the size of their 4 pots.

Has a done done this already.

Alun
Al

Series 1, 2+2
undergoing renovation

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abowie
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#6 Re: Rear brakes

Post by abowie » Sun Jun 15, 2025 10:23 pm

alunwill wrote:
Sun Jun 15, 2025 3:54 pm

Has a done done this already.

Alun
Yes this is what I did when I fitted Coopercraft front calipers to my first E Type years ago. Moving the fronts to the rear maintained the brake bias at stock.

To be honest though I really couldn't feel any difference with the braking for day to day driving.
Andrew.
881824, 1E21538. 889457. 1961 4.3l Mk2. 1975 XJS. 1962 MGB. 1979 MGB.
http://www.projectetype.com/index.php/the-blog.html
Adelaide, Australia

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40GT
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#7 Re: Rear brakes

Post by 40GT » Mon Jun 16, 2025 6:52 am

Does the S2 rear system offer any volume change?
Sean

S1 2+2 1966 BW RHD
XK120 1954 comp LHD

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