Pedal box? All round disc..

**SidewaysMk1** · 24-10-2003, 12:09

As the rear drums on my escy dont work i would like to know if when u r changing to all round disc, do u have to use a pedal box. Or can a good enough master cylinder work.

thanks guys..

**popuptoaster** · 24-10-2003, 19:57

my rally slag has a standard master cylinder and disc's on the back, appears to work fine. havnt driven it a huge amount yet though, never stamped hard on em.

**BigDave** · 24-10-2003, 20:03

Iwould say if its good enough to squeeze drums it should be able to squeeze discs!! Give it a try, nowt to loose!!

**Escortmk1** · 25-10-2003, 09:39

The pistons inside calipers are a lot larger than in drums.

I was advised to use a bias pedal box as the standard master cylinder would not displace enough fluid.

Andy

www.escortmk1.homestead.com

**SidewaysMk1** · 25-10-2003, 11:57

thought it took more pressure to operate drums than calipers? isn't that true.

**Dom** · 25-10-2003, 21:06

I think you'll need a bias otherwise you could run a risk of locking the rear brakes up (not good).

**SidewaysMk1** · 25-10-2003, 21:30

do u mean the bias pedal box or jus a bias valve will do.

do rwd sierra's have a bias valve.

**popuptoaster** · 25-10-2003, 21:32

a lot of vans have a bias valve for hen they run empty, think its linked to the rear suspension, could it be used as a cheapo ajustable jobby?

**ludsonline** · 26-10-2003, 06:09

Hi,
Check out Caprisport @ http://www.caprisport.com/ and have a look at there brake kit no bias pedal boxes there

Hope this helps

Ludsonline

**SidewaysMk1** · 26-10-2003, 12:01

Hi,
Check out Caprisport @ http://www.caprisport.com/ and have a look at there brake kit no bias pedal boxes there

Hope this helps

Ludsonline

on that site they say u shouldn't use front calipers on the rear. Why is dat?

**ludsonline** · 26-10-2003, 23:28

It's todo with passing the mot you can't have a hydraulic handbrake I think (might be wrong) also they give to much braking force.

**SidewaysMk1** · 27-10-2003, 00:06

thought all calipers were the same (front and rear) doesn't it depend on the master cylinder and if a bias vavle is used that determines the amount of pressure goin to the rear.

**BigDave** · 27-10-2003, 18:43

It depends on cylinders and the bias valve yes. Normally for front and rear set ups using a bias pedal box you would use two different sized cylinders. Say a .625 or .75 etc... Also there is a blance bar which basically puts more force into one valve than the other depending on which way you turn the thread. You would want more brakes up front so you make that the stronger, etc...

You can just fit a bias valve into your normal brake system and these are pretty cheap to buy from many distributers out there. Not worth bodging something else to make do, they really are pretty cheap!

You can use front calipers on the rear if you like. The reason they dont get used is down to the fact that a mechanical system is used alongside the hyraulic on a rear caliper. As rightly said this is for Mr MOT because you need to have a secondary method of slowing a vehicle should you loose your hydralics. To get round this you can either...
1. use a rear caliper from another vehicle that already has the mechanical fitting.
2. fit a hydraulic caliper for stopping and a single piston mechanical "spot" caliper for your handbrake.
3. become mates with an MOT tester and just fit em anyway!!

But once again this is just my thoughts so dont quote me!!