Brake woes (B4, 2.0 16v)

[@ndy]

Morning all,

Having a bit of trouble with my brakes lately.

Last week I lost most of my breaking power, after a bit of research and advice from a number of people (both online and in person) I changed the master cylinder last night. I drove the car this morning and the brakes are still RUBBISH!

My system comprises of:

S2 calipers (refurbished with new seals and pistons prior to fitting)
EBC Yellow stuff pads
Braided brake lines (front and rear)
Standard rear calipers (again, refurbished before re-fitting)
standard brake fluid
276mm discs (25mm thick)

I've recently changed from the incorrect 280mm (23mm thick) discs to the correct 276mm discs.

Before when i was running on the 280 discs the brakes felt crap but better than they are now. Even our lasses '05 Clio 1.4 has better brakes than my Audi at the moment.

I can't believe I've got the best out of the S2 brakes!

Has anyone got any ideas?

I've checked all the calipers aren't seized, there are no leaks, all the pads/discs have done less than 1.5k miles, the fluid it new, the system has been bled and there is now a new master cylinder.

I'm wondering if the yellow stuff pads need changing for standard items, just thinking they aren't getting hot enough?

Any help / advice would be great!

Cheers,

Andy

[@ndy]

turns out the servo is FUBAR'd!

[ManiacuV6]

How did you bleed your brakes ? Which king of brake fluid did you used ? DOT 4 , Dot 5 ?

[@ndy]

using DOT 4. used a pressure bleeder to bleed the brakes.

[ManiacuV6]

Did you installed the callipers in the right place ?

[@ndy]

Did you installed the callipers in the right place ?

how could I have put them in the wrong place?

[ManiacuV6]

I seen that in a car . The owner put the left caliper in the right hence the bleeder was in the lower side of the caliper. So the air was trapped in the higher side.
Try to apply like 15 psi in the reservoir by using a modified cap with a wheeel valve. Do you have Abs?

[@ndy]

Already know my calipers are the right way round because I fitted them the wrong way round after refurbing them lol. They've since been put the right way round.
The system was bled using a pressure bleeder with the air pressure coming from a tire with about 30 psi in.

Yes, I have ABS.

(Thanks for your comments so far)

[ManiacuV6]

Do you have brake fluid going off the bleader? Are your brake hoses new?

[@ndy]

All the brake hoses are new yes.
Sorry what do you mean? going off the bleeder?

I've just had a quote for the Servo, well it was about 10 minutes ago, I've just about recovered from the shock!
Before I either buy a new one or find a second hand one, whats this brake 'bomb' I keep reading about? Could this be causing my problems?


Please help?!

Andy

[@ndy]

Ha ha ha ha Audi want £438 for an Accumulator!

[GazzaG60]

is the bomb the same as the s2 on the 16v. I know they aint cheap. for reference the bomb is the pressure accumulator that looks like a big grenade. cartoon bomb like hence the name. can you get 20 presses without the engine without the pedal goiung rock hard.
do the s2 calipers bolt straight on just out of interest. whats the pedal travel like?

on my 16v the pedal is good but brakes are poor. tjhey feel under braked. having said that the s2 did feel like that too. IMO ebc are not great but dependant on calipers are cost effective. they need a bit of heat that's for sure. tbh id expect the bite factor on the clio brakes to be much better.

fitting big brakes on the front helped loads. bite wasn't great but stopping power was. from high speed the 6 pots were a revelation.

gotta say I cant wait for bigger brakes. I drive to cawthorne, Barnsley to work and the twisties need brakes.

my recommendation would be 4 pots or 6 pots to get real brakes.. on a 16v with 4 stud maybe harder to get wheel offset correct im not sure. in the corrado days we used willwood or brembo off a cupra r Ibiza. they fit a tighter wheel to caliper design. s2 has miles of space.

[ManiacuV6]

4 or 6 pot is a nice dream but unfortunately is expensive .
I didn't knew that you have a hidraulic servo mechanism .
Which colour is your power steering fluid? It shouldn't be RED.
The power steering pump isn't making a wining noise?
Without engine runing press the brake pedal and keep it pressed. Start the engine. Now you should feel that the pedal is going down .
Test 2: run the engine for 3 min on idle . Stop it. Pres the brake pedal 3 times on a row. You should feel that the pedal is getting stiffer .