Cooper to Cooper S brake upgade questions

[Bertam]

A friend not on the forum has a 1962 Morris Cooper that retains the original 7" front discs. The original 997 engine was replaced in the distant past with a modded, twin carbed 1098 by a prior owner. In spirited driving he find the brakes are a bit 'lacking' and so desires increased performance. He also wants to retain 10" wheels without flares and has been considering going to Cooper S 7.5" front brakes. This is a road car and other than braided hoses, it retains a totally standard Cooper spec braking system.

Has anyone done this switch and if so:

A - What is required to do it?

B - Are you happy with the results?

Thanks for your replies.

Cheers,
Andrew

[timmy201]

He'll need a full brake conversion kit from minispares etc as the 7" discs had the same CV joints as the drum brake cars.
E.g.
http://www.minispares.com/product/Class ... J4028.aspx

You can keep the hub uprights as they are the same, but is probably cheaper to buy the whole kit. You can then keep the 7" brakes complete in storage. It's worth checking/replacing the rear wheel cylinders too if they are different? Here is the list:
http://www.minispares.com/catalogues/cl ... px?1~9~105

You'll also need a different set of wheels depending on what wheels are fitted now, as more than likely they'll be outside the guards.

[Bertam]

Thanks for the quick reply Timmy. Currently his car has 4.5" x 10" Minilifes with 165/70 A008's on it.

[Spider]

If it still has the original Cooper Master Cylinder, that'll possibly want changing, these were only 5/8' bore, so would give it long pedal travel.

If it still has the Intensifier, might want to ditch that too.

Rear Wheel Cylinders should be sweat (5/8").

Ideally as well the original Pressure Sut Off valve (in the rear subframe) is probably a little high in it's shut off pressure, so a lighter spring would be the go here or an adjustable.

The original S set up was of course boosted, but many people run without them. Up to your mate I guess.

[Bertam]

Thanks Spider. Looks like he has some choices to make as well as some shopping to do..

[Vegard]

If you fit proper pads to a 7" system, they WILL BE adequate for a roadgoing small bore Mini. I've just had a friend of mine race a 998 Cooper, and that works adequatly.
Yes, 7,5"s are better no doubt, but 8,4" with four piston calipers are even better.
Where do you draw the line?

[timmy201]

If you fit proper pads to a 7" system, they WILL BE adequate for a roadgoing small bore Mini. I've just had a friend of mine race a 998 Cooper, and that works adequatly.
Yes, 7,5"s are better no doubt, but 8,4" with four piston calipers are even better.
Where do you draw the line?

Assuming you have the Cooper 998 brakes... The majority of 997 cars had smaller pads

[Andrew1967]

I swapped the 998 Cooper brakes on my Mk2 Cooper for S brakes and they are far, far better than the standard Cooper brakes.

No more Cooper brake fade when braking at speed travelling downhill fast approaching a give way junction New pants please

They are non-servo'd so require more pedal effort than the brakes on my 'S (which are really good.)

As has been said, you can use the hubs but will need CV joints, driveshaft nuts and the tapered washers, drive flanges, discs and callipers.

Also worth checking the master cylinder, rear cylinders and limiter for compatibility.

[Spider]

I found Cooper Brakes, both early and late, really good - for left foot braking!

What's that? For stopping?

Bhahahahaaha,,,, yeah, right,,,,,,,

[LMM76C]

Master cylinder change to S is essential. Without it the pedal will not be just "long" but will hit the floor before it gets round to working at all.

[Bertam]

Thanks for all the additional replies and useful information everyone.

One further question. Which pads are considered best for use with 7" brakes? Consider this is a road car that has been modded a bit (braided lines, 165/70 A008 tyres and alu wheels, uprated shocks + Hi-Los and fully adjustable suspension bits as well as ~65-75HP from a moderately warmed over twin carb 1098). I do not know what pads are on it right now?

[timmy201]

I've heard the "greenstuff" ones were alright (I don't know if they are still available). They only fit the Cooper 998 sized calipers though. You can apparently mill the 997 size calipers out to take the 998 size pads.

One of the biggest problems is the 7" discs are so thin, and they wear quickly (more so with better pads) and don't have as much heat capacity.

http://www.minispares.com/product/Class ... HT223.aspx
http://www.minispares.com/product/Class ... TIMAX.aspx

[carbon]

Master cylinder change to S is essential. Without it the pedal will not be just "long" but will hit the floor before it gets round to working at all.

I've been running the 5/8 bore master cylinder with a standard S disc set up. For about 20 years with a fast road 1275.

Never had any problems with excessive brake pedal travel. Gives good weight to brake pedal, and I don't need a servo.

The only minor downside is that the fluid reservoir is the smaller version, not the taller S type. But this is not a problem for car being used just on the road.

[Andrew1967]

Master cylinder change to S is essential. Without it the pedal will not be just "long" but will hit the floor before it gets round to working at all.

I've been running the 5/8 bore master cylinder with a standard S disc set up. For about 20 years with a fast road 1275.

Never had any problems with excessive brake pedal travel. Gives good weight to brake pedal, and I don't need a servo.

The only minor downside is that the fluid reservoir is the smaller version, not the taller S type. But this is not a problem for car being used just on the road.

I didn't have any problems with the standard master cylinder set up either on my purely road use only car. I did buy one of those plastic reservoir extenders but never fitted it (mainly because I mislaid it ).

Definitely no problems at the moment as its been off the road for three years and is unlikely to go back on the road for the forseeable

[LMM76C]

You must be talking about a different item. The larger S m/cyl was essential in period - which is why BMC fitted it as standard....

[AndyB72]

I'm using green stuff on the 998 disc setup on my 1100 Mini. I did the Blyton track day with them last year and they were great, I didn't go too mad but if I did I reckon they would have fadded quickly. I'd give the pads a go first, if you're not happy with them I'll buy the pads from you

[Andrew1967]

You must be talking about a different item. The larger S m/cyl was essential in period - which is why BMC fitted it as standard....

Here's a picture of the my Mk2 998 Cooper standard master cylinder in question. You are of course right that it should have the correct large reservoir (and I wouldn't recommend it to anyone), it's just that a non servo S set up can be used with a standard sized can.

You have to be more careful on checking the fluid level as the pads wear and then be careful when pushing the pistons back for a pad change.

[CooperTune]

I'm wondering why if you have disc hubs you can't just buy a set of S CVs, a pair of S disc and calipers. You will need the taper washer and a rear seal spacer and the job should be done. As for the master not much chance of having pad wear in a day to run low on fluid. I ran an aftermarket 5/8 master without booster on my vintage racer and the pedal was a little deeper but the feel was great. Steve (CTR)

[Andrew1967]

You'd need S drive flanges as well, as the 997/998 flanges are different.

But thinking about it, could you use the smaller CV joints with the 998 flanges fitted to the S disc ??

[CooperTune]

Sorry I thought about it on the way to the shop. You will need S drive flanges as well. I pre assembled two engines took measurements, striped and loaded for a trip to machine shop in the morning. Hope I did not miss lead anyone. Steve (CTR)