Spongey Pedal

[andykandy205 0]

Hi read through every post i can find but to no solutions that i haven't tried...

So replaced all my brakes pipes, 1.6 compensator split into two rear calipers (dont think it makes a difference)

Replaced master cylinder bleed brakes about 10 times by now but yet i still cant get a hard pedal after pumping with engine not running, the brakes are working but i dont particulary like to have to put my foot right down on the pedal.

 

So any other suggestions it could be, oh Gti-6 brakes up front..

Any help appreciated.......

[welshpug 1,655]

have you got a small bore Master cylinder on there?

[andykandy205 0]

its got a 20.6mm on it, i must add it used too work...

Edited September 8, 2009 by andykandy205

[billybluesky 1]

Like you i recently replaced hoses calipers pads etc but had pedal almost to the metal i cured it by fitting a scrappy 406 non abs master cylinder(23mm) problem cured. Oh dont forget you have to pump the pedal rapidly 3 or 4 times when bleeding the rears due to the compensator hope this helps

[dcc 855]

Isn't there a 1 way valve on the servo, I'm sure Jon and Trev (Wildejon and Revla) had this exact same problem on the euro trip! this valve was a part of their cause!

[andykandy205 0]

right today no matter how much fluid i bleed through im still getting air bubbles very very small but still there any suggestions

[andykandy205 0]

anyone im getting desperate

[Bassman 1]

its got a 20.6mm on it, i must add it used too work...

 

It used to work (have a small amount of pedal travel) with a 20.6mm cyclinder and GTi6 brakes or it used to work with original brakes?

 

I would have thought you needed a bigger master cylinder as the GTi6 brakes have a much larger piston and most people find the brake pedal travel too much with a 20.6mm cylinder.

 

I have a 406 23mm cylinder in mine with 307HDi brakes and they are smaller pistons than the GTi6.

 

If you are convinced this setup worked before, the only other thing is to check the rod that connects the brake pedal to the master cylinder is correctly adjusted, if you have altered this at all.

 

Hope this helps.

 

Rob

[andykandy205 0]

the brakes used to work with gti6 brakes i have looked at the servo rod and it measured 22.3mm so point 1 i dont think will make that big a difference..

 

Right basically had this setup on 1 car then wrote it off then swap to another only difference is used to have 1.9 compensators now i got the 1 1.6 compensator and now they dont work properly

Edited September 9, 2009 by andykandy205

[Bassman 1]

the brakes used to work with gti6 brakes i have looked at the servo rod and it measured 22.3mm so point 1 i dont think will make that big a difference..

 

Right basically had this setup on 1 car then wrote it off then swap to another only difference is used to have 1.9 compensators now i got the 1 1.6 compensator and now they dont work properly

 

.. and to confirm, this is the same master cylinder as well from the previous car?

[andykandy205 0]

no new 1 cause i thought it was the master cylinder so bought a new one......

On further thinking does it matter where the compensater is mounted

[Bassman 1]

no new 1 cause i thought it was the master cylinder so bought a new one......

On further thinking does it matter where the compensater is mounted

 

I wouldn't think so in terms of the pedal having a lot of travel.

 

I can only say, that with a 20.6mm master cylinder, the pedal travel with GTI6 brakes will be very long. If you are sure the two master cylinders are the same size, then this is puzzling, but I think if you move to a 22.2mm cylinder from a 405 or a 23mm from a 406, the travel will be much shorter.

 

 

Rob

[floodys 4 1 Cars]

just to add my bit, i have gti-6 brakes on my 1.9, when it had the 1.9 master cylinder the pedal went down a bit before it worked. i think this is the prob you get with gti-6 brakes, i then brought a second hand 406 23mm master cylinder, have fitted it and now cant get brakes to bleed properly, altough saying that it works every now and then but when your lowing down for a junction the pedal will slowly drop to the floor.

A mate of mine thinks the master is no good, maybe been on a car and off and stood for a while? anyhow, i'm off to the ring next week so in the meantime i'm going back to the 1.9 8v one!!