13 replies to this topic

[Patriot]

Hi,

 

I have just removed the front drum brakes from my 1977 clubman and replaced with KAD 7.5 set up.

 

I have not bled brakes yet, I have been told by a friend that that I need to remove the bias valve that is mounted on the rear sub-frame, that was originally for the drum brake set up.

 

Is this true? would the new KAD set up work fine if I kept the bias valve in place?

 

Thanks

[ministar]

I seriously suspect you are going to be locking up the rear drums, as you have a far more powerful set of brakes at the front. An adjustable in line bias valve would be a good way to go if you are looking to spend a bit of cash. I just bought a Tilton in line bias,,,yet to be fitted though.

 

Edit.. But removing the bias valve on the rear subframe will only make your problem worse I think.

Edited by ministar, 11 June 2014 - 09:48 PM.

[Patriot]

Interesting...... thanks

[Captain Mainwaring]

Can't the suppliers give the braking effort figures? Anyone can bolt odd brake components onto a car, but it seems few can do the calculations to know what's going on afterwards.

[The Matt]

The bias valve on the rear subframe could be replaced with an adjustable valve of the same fitting.

 

There is an adjustable version of THIS , but I can't find it ATM. I know I've got one in the garage.  Not sure if the adjustable one is a Cooper S fitment or what.

 

But, you need to consider the hydraulic system as a whole.  The bore of the master cylinder is (I think) different on the Cooper an 1275GTs that were fitted with front discs. The rear wheel cylinders were also different bore on some.

 

You can change your rear braking effort just by using larger or smaller bore cylinders.  I struggled to get mine right when using a bias bar pedal box and Minisport 4 pots and standard rear cylinders.

I'd agree with CM, and say talk to KAD and see what they recommend for your system.

[The Matt]

And by the way, 1/2", 5/8" and 3/4" bore rear cylinders are all readily available. That may be the way to go in terms of cost, but I'd definitely talk to KAD and see what they suggest.

[Dan]

Is there a bias valve at the back of a '77 car?

[The Matt]

shouldn't be, should be the bulkhead type on post-'76 shouldn't it?

[The Matt]

aaaaah, wait.  A fried told him it needs doing.  Maybe he's not looked at the car yet?

[Patriot]

Will get into my pit tomorrow and take some pics of bias valve, will post pictures tomorrow night.

Hopefully it will help figure out what set up I have.

I will talk to KAD also.

Thanks.

[Patriot]

Hi,

 

Just took some pics of the brake set up on the 1977 Clubman, I take it that this is the bias valve, if not them what type of valve is it (if anyone can comment please).

 

Any further thoughts on removal or retain this set up would be much appreciated.

 

Thanks

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[Gr4h4m]

Yep that shuts off a a certain Line pressure, you should bear to hear it click when you stamp on the pedal.

I'm running one on my kad setup 7.9" vented four pots with 1275 RWC and a yellow tag master cylinder up front.


You could always ring KAD for advice they have been very good to me.

Graham

[The Matt]

http://www.minispare...|Back to search

I have one of these fitted to mine. Not sure whether it's because it did have Metro 4 pots on it at one point, when I would have originally had drums all around. Other parts suppliers are available! I looked on Minisport but couldn't see one. It looks like the non-adjustable version of these (like you have currently) were fitted until '78.

[Patriot]

Thanks everyone.

Looks like I need to part with some more dosh.