Wanted: Clubsport Rear Brake Calipers

[Laurence7]

I’m considering upgrading the rear brakes on my early Clubsport. Does anyone have a pair of 4-pot callipers going begging?
Laurence

[RobC]

I guess you know you have to change the uprights as well? Rear 4 pots are the same as the fronts but with smaller diameter pistons.

[Laurence7]

Hi Rob
Yep - knew the rear uprights were different, but didn't know the rear piston diameters were smaller than the fronts, though it makes sense that they would be - thanks for that.
Do you happen to know what the correct piston diameter is? Also, do you know if the mounting lug pitch is the same as for the fronts? Wilwood website only seems to quote 5.25" (133.35mm) pitch for the Billet Dynalite range (ref http://www.wilwood.com/Products/001-Calipers/020-B...
Cheers
Laurence

[RobC]

Going from memory they are the same mounting points as the front. I don't have the sizes to hand but should be able to get them before the end of the week if thats of use

[Laurence7]

Hi Rob
Don't go to any great trouble, but if you can get a measurement of the pistons in the next week or so, that'd be great.
I'm hoping to get hold of some good second-hand ones if poss ( anyone? ), otherwise I'll buy new.
Cheers
L

[RobC]

Will do.

Might be changing my 4-pot fronts early in the new year but not a lot of good to you

[k13job]

I currently have 4 pot vented fronts on my clubsport, but only do Hillcimbs and sprints so they are too heavy and over the top as if anything the problem is not cooling but getting heat into them.

I have considered returning it to the standard non vented, would do a swap, mine have new discs and pads with only a few miles use. I am worried and confused by the comment about having to swap the uprights?

Please explain the problem with the uprights as I thought the front and rear were the same?

[RobC]

The mounting lugs on the 2 pot calipers are closer together thus the need to change the rear uprights to Prosport ones that have the lugs further apart for the 4 pot caliper.

For your requirement I'd look at changing the pad make/material rather than changing the whole setup.

[k13job]

I am running a good road pad that works from cold , so no real problems with the break efficiency, but those vented discs weigh a ton, nearly double the standard rear solid version, I could hardly believe how heavy they were when I replaced the worn out discs with new ones.

I had replaced the rears the previous year (they were were so worn that the piston came out past the seal).

[nick997]

Laurence, I bought an SR4 earlier this year that came with a load of spares including some calipers. I'm at work at the moment and can't remember for the life of me if I've got a full set of 4 or just fronts, let alone whether SR4 parts will fit a Clubsport. Perhaps RobC, who's knowledge of these cars never ceases to amaze me, will know the latter.

I'll have a look tonight if you are interested. If there are any key dimensions that you want to know then let me have them and I'll get the tape measure out.

Nick

[RobC]

Ah, if you are looking to save weight then thats the way to go. You'll need to remove some of the spacers from the caliper for the thiner disc.


Prosport and SR3 are the same caliper lugs so its a fair assumtion that the SR4 is the same. The only issue is if the calipers are for the 240 or 260mm discs.

[Laurence7]

Hi Nick - Yes, I'd be very interested if you have some rears - I think there's a good chance they'd be the same as for a Clubsport.

[nick997]

Laurence, I only have two calipers, no idea if the are fronts or rears. They are 4 pot jobbies with approx 35mm pot diameter if that helps. I'm in North Essex near Stansted airport if close and you want to take a look, will be driving down to Slough on Sunday morning if I go past your door.

Forgot to say - they are Hi-Spec with Radical logo cast onto them.

Nick

Edited by nick997 on Tuesday 20th November 20:56

[BertBert]

Just been to look at my spares. I have a pair that are used and of uncertain vintage. The pots are 44mm diameter and it's hard to see how they would put bigger ones in.

Anyway the part nos are 120-4993 which makes them rears according to Rob's webby (need to double check both) and they don't have a gap big enough for the vented front discs.

Let me know if they are of use Laurence.

On the subject of calipers, one of my fronts has just siezed. I haven't had a look yet, but I am fairly sure of the diagnosis from the creaking sound when the wheel goes round and how hard it is to turn.

Is refurbishing them a tricky DIY job best left to the pro's or an easy DIY job? I plan to do all 4 to save problems next season.

Bert

[RobC]

Could also be a warped disc or maybe a duff wheel bearing causing those symptons. However if it is the caplier they are pretty easy to do yourself. Seal kit and pistons are available from Rally Design for sensible money. Before removing the caliper from the car pump out the pistons by about 10mm this will make getting them out easier once the caliper is off the car. For fitting just make sure the caliper is completely clean, smear the new seals with some rubber grease and fit back into the caliper. Refit new pistons, they will be a friction fit. Once fitted back on the car pump them out again and you should be able to push the pistons back in with finger pressure.

Interesting point re part numbers, I would have thought the rears have 35mm pistons bt it does look like the 4993's have 44mm pistons. As mentioned above I'll double check on Friday and update everyone on this thread

[Laurence7]

Bert – If the spare callipers came with your car and are too narrow to accommodate a vented disc, then I guess they must be from the rear of a Clubsport, so I’m definitely interested! Just need to be sure on sizes - I’ll call you to discuss further.

Nick – As far as I know, Hi-Spec callipers were never fitted to the Clubsport, although I see no reason why they couldn’t be. The Hi-Spec calliper design is quite interesting – it’s more compact than the Wilwood design, allowing the use of a bigger diameter disc to be fitted within a 13” wheel – up to 280mm in lieu of 240mm for the Wilwood. I’m not sure that a Clubsport (with its low weight and limited down-force) could really make proper use of bigger (and heavier) front discs. Does anyone have any experience of this?

For info on Wilwood “Billet Dynalite” Brakes (I think these are the ones used on Clubsports):-
http://www.wilwood.com/Products/001-Calipers/020-B...

For info on Hi-Spec brakes with Wilwood bolt pitching:-
http://www.hispecbrake.co.uk/calipers/R114dynalite...

Rob – Awaiting further dimensional details with bated breath! I’ll check out the fronts on my Clubsport this evening and report findings tomorrow.

Cheers - Laurence

[BertBert]

okey dokey Laurence, give me a shout.
Bert

[Laurence7]

Dimensions gleaned from the 4-pot Willwood callipers on the front of my Clubsport:-

Attachment bolt pitch: 5.25” (133.35mm)

Piston diameter: 1.75” nominal (approx 44.5mm)

[BertBert]

so that's a bit confusing if the rears are supposed to have smaller pistons and my spares are rears?
Bert

[RobC]

Here we go then, got my hands on a SR3 today which has the following -

Fronts - 120-5322 - these have one 44mm and one 35mm piston

Rears - 120-5093 - these have two 35mm pistons

This confirms what I was thinking but still doesn't explain why some of you guys have 44mm rears? maybe it was a quick fix for a previous owner to fit those. Confused....I am