Brake system set up

[alex_e3]

I've just been through lots of searching, but i thought i'd post after not finding what i'm looking for.


I bought a 285mm wilwood 4 pot set-up a while ago. Now i'll be fitting these soon - trial fitted them today and thankfully they fit under willy rims! The car has ABS which doesn't work, so i'm planning on removing that. As everyone knows though, this requires a new master cylinder with 4 ports to be fitted. Also, after checking, the rear bias set-up is seized and completely bolloxed!

Now seeing as i've gotta fit a new master cylinder and front brake lines minimum, i've decided to completely overhaulthe brake system. New lines throughout, new uprated master cylinder, braided lines all round. I'm also wanting to run an in-car adjustable bias valve, as there are no seats in the back and the rear load is unlikely to change much.

Questions are:-

1) My wilwoods didn't come without brake hoses, so tried them on today and the standard hoses are way too short, as the connection on the calipers are bang in the middle. What braided hoses can I use that will be long enough? Considering also i might widetrack in the future.

2) After reading another thread, i'm assuming the 406 V6 master cylinder would be the correct one to use?

3) Where would be the best place to route the brake lines in and out of the cabin?

4) What type of bias valve would I need to buy? Also, the ones i've seen only have 1 brake line going in and out of them. Does this mean I have to only run 3 lines from the master cylinder and blank one off? Then split the line running out of the bias valve 2 ways?


Any and all help is much appreciated guys!

Cheers,

Al

[speed]

1, you can just make a brake pipe from wilwood to the mc

2 yes a 406 master cylinder is 23.8mm, non abs lagunas run 22.8mm which could be used and maybe cheaper?

3, down the centre tunnel then a t piece at the rear bench location then onto the rear calipers

can pic a bias valve up from ebay or tweeks/rally design etc
there is a screw type and a lever type, most ppl prefer the lever type

im pretty sure you can run 3 lines from the mc but not 100% sure

[stevie_b]

What's your current ABS master cylinder got on it by way of ports? If it already has two then I'd just use that to start with. If you find that you don't like the 'feel' of that then maybe look into swapping the MC with a different one, but what you gain in apparent ease of depressing the pedal you lose in the fact that travel is increased, so I'd try what you have first and see if you are happy with it.

Assuming you do change the MC then a dual or 4-port design are both fine. If a 4-port then you need to make sure it is a dual circuit item and use one circuit for the front and one for the rears (road cars have these across opposite diagonals for safety reasons, but you can't use that 'plumbing' with a single in-car adjuster) and you can either blank off the spare port or T-piece them together.

The bulk of the racing fraternity use Tilton or AP bias adjusters and ideally you'd run two master cylinders at the pedal box with a physical balance bar to alter the bias between the two circuits - the bias adjusters that run in line with the rear circuit are a cheaper method to try to achieve a similar thing. Both AP and Tilton do a lever and screw type of these adjusters - the levers are good for changing the bias during the course of a lap or as tyres degrade during a stint and the screw ones give a greater level of control of the bias but are not as easy to adjust during a lap or return to a 'known' setting when you restore the car to fresh tyres. Wilwood do some also, which you can sometimes find cheaply on auction sites.

[alex_e3]

1, you can just make a brake pipe from wilwood to the mc

Eh? Doesn't it need to be flexi hose at the end? Or have i misread? Ideally just need to know what hoses are ideal to use with wilwood 4 pots?


Stevie, my current master cylinder has 2 ports on it. I'm probably just gonna ditch it and get a new one with 4 ports to be honest. What's this about non-diagonal dual circuits then? - why will these not work with an in car adjuster? Also, if i buy a new master cylinder, is a laguna or 406 one likely to be of this diagonal type? Hence if so, which master cylinder could i buy to work with the setup?


Cheers for both your replies guys!

[speed]

i thaught you ment new braided lined from master cylinder to wilwood caliper direct. not using hardlines

wilwood uses a 1/8 npt taperd fitting so the std style williams wont fit

[speed]

and i would also like to know about duel curcit m/c?

[Twincam]

Braking circuits work diagonally o/s front with n/s rear caliper and n/s front with o/s rear. When you want to run a bias valve you need to T piece 2 lines together (or sugested it is poissible to block a port off).

The circuits are designed like this so in the event of a hose burst you should still get some braking from the unaffected circuit.

If you were just to pipe the present 2 rear caliper pipes together without re-pipeing the master cylinder and a hose burst you would totally lose all brakes

By moving the pipes in the master cyc;inder round you change the 2 braking circuits from being diagonal to just front and back. Not ideal but at least you'l still end up with some brakeing

hope that makes some sense

[MAXIBOY]

I've just been through lots of searching, but i thought i'd post after not finding what i'm looking for.


I bought a 285mm wilwood 4 pot set-up a while ago. Now i'll be fitting these soon - trial fitted them today and thankfully they fit under willy rims! The car has ABS which doesn't work, so i'm planning on removing that. As everyone knows though, this requires a new master cylinder with 4 ports to be fitted. Also, after checking, the rear bias set-up is seized and completely bolloxed!

Now seeing as i've gotta fit a new master cylinder and front brake lines minimum, i've decided to completely overhaulthe brake system. New lines throughout, new uprated master cylinder, braided lines all round. I'm also wanting to run an in-car adjustable bias valve, as there are no seats in the back and the rear load is unlikely to change much.

Questions are:-

1) My wilwoods didn't come without brake hoses, so tried them on today and the standard hoses are way too short, as the connection on the calipers are bang in the middle. What braided hoses can I use that will be long enough? Considering also i might widetrack in the future. [not 100% sure on the fittings but 19V hoses length should be ideal..]

2) After reading another thread, i'm assuming the 406 V6 master cylinder would be the correct one to use? [can use either but i just go standard..]

3) Where would be the best place to route the brake lines in and out of the cabin?[ why though the cabin..]

4) What type of bias valve would I need to buy? Also, the ones i've seen only have 1 brake line going in and out of them. Does this mean I have to only run 3 lines from the master cylinder and blank one off? Then split the line running out of the bias valve 2 ways?[ i would just go standard. as well as allowing for weight it also allows for weight transfer..but if you are going too run one..you run two lines as normal t them together before the bias and re split them after wards..]


Any and all help is much appreciated guys!

Cheers,

Al

answers above ..

[alex_e3]

Cool thanks again guys.

Speed, the wilwoods I have bought aren't from the group buy. They're a different type, and the standard hoses fit them as i've tried them! Might just end up going and getting some wilwood hoses to be honest, as the OE ones were short by quite a way on full lock.

Twincam, I think I understand where you're coming from. So basically I could go and buy a new master cylinder, and then simply swap the position of the brake lines so that the 2 front pipes are on 1 circuit, and the 2 rear pipes are on another. Does that sound right?!

I'm thinking I will use all 4 ports and T-piece them before and after as some of you guys have said.

Maxi, I want to run the lines through the car due to the fact i'm planning on running a bias valve in the car - so the lines need to come into the cabin at some point. I'm doing this as i'm not paying the no doubt ridiculous price that renault want for a new bias valve!


Cheers!