Brake pedal has excessive travel after fitting MK4 rear cali

[corrado g 0]

I have just fitted new discs and pads to the rear of my 1992 g60 whilst doing this i fitted mk 4 golf calipers and the hoses to accomodate this. On completion i took the car out on a test run and fluid had leaked from one of the unions so i tightened it and re bled the system. the brakes have never worked since. i bled it trough twice starting the the longest brake line finishing at the master cylinder. i replaced the master cylinder as there was continuous air in it and sometimes you hear of them failing when the system id bled, its still the same £160 later :( It sort of stops if you pump the pedal but its still not road worthy enough. I an stumped as to what it could be and have used the search to no avail. I was wondering if i have missed something? :? Should i bleed the clutch too? Has the servo gone? The car has ABS and it stopped fine beforehand. Any clues? Thanks in advance.

[tonedef 9]

If the pedal pumps up then there's air in it, simple as that. Did you do the rears with the balance valve compressed to ensure a good flow to them, did you bleed the nipples on the ABS pump and the master cylinder? Brake bleeding is hardly rocket science although it can sometimes take a little perseverance.

[Supercharged 2]

May be a problem if you have got air into the ABS system - are you pressure bleeding?

 

With the mk4's you need bleed then pump the pedal about 50 times, connect the handbrake and bleed again, pedal should feel ok and get better after they're bedded in and handbrake will be excellent!

[steveo29 0]

i had hell of a job bleeding mine when i fitted mk4 calipers...couldnt get it right with a easy bleed

 

in the end a pressure bleeder at a garage sorted it in minutes

[corrado g 0]

I did not pressure bleed the system, nor did i bleed the abs unit. I will have a go over the weekend. Also i didn't bleed it with the handbrake cable disconnected, i thought i was going wrong somewere. :oops: Ah well you live and learn thanks guys, i will post up the out come. :wink:

[corrado g 0]

Hi after lots of bleeding and getting no further i found out that the abs was getting no current to it and i had to test the loom form the inition to the pump and there was a break in it so its all fixed now. Still has the pedal problem though :(

[corrado g 0]

Well i will update this as i found the problem, wich turned out to be a faultly brake bias valve which had trapped some air in it. Posted up wanted thread :?

[Supercharged 2]

brake bias valve which had trapped some air in it. Posted up wanted thread

 

Nice one - get a new one from VWspares, not an expensive item!

[corrado g 0]

Yes just got one all working now. Cheers.