Hello!

I have a A4 Avant 1.9 TDI (B6) and I have changed the front and rear rotors and pads last week putting brand new Ferodo pads and Brembo Max rotors.

After the pads "bedding process", the car seems to brake worst than before andsometimes(specially if I brake harder)the peddal goes hard anddoesn't brake at all (almost nothing)...I even tryied to brake harder but it doesn't even activate the ABS... I can only feel this if I brake hard because during a normal driving it works fine...

What can be happening??
I have not dissambled the brake fluid lines and I have pushed the pistons with a standard C-clamp.
The front ones were easy, but on the rear ones I had to use a universal pair of pliers to scew the piston in at the same time as I was pushing the piston with the clamp.
Did I made something wrong during the equipment change? The only thing I didn't remember to do was tocheck thefluid level after pushong thepistons...
Should I bleed the system?? Is that an easy task to do?
Thanks
Regards
RG

 

bleeding is easy but youll need a friend

 

the ebrake should self-adjust after using it a few times. you def should have had the brake fluid resv. cap off when pushing the caliper pistons back in, and remove extra brake fluid with a turkey baster, if needed. The rears must not have been worn much, since you didn't need the tool to push the pistons back in. If there was air in the lines, the pedal would probably feel soft/spongy. I don't think the ABS is working right, from your description. check that you didn't accidentally disconnect/damage the abs sensors or wiring. Do you have an ABS light "on" on the dash?
Also, not sure on the materials of the pads you got (I'm not familiar yet with the Ferodo pads, and you did not specify - semi-metallic, ceramic, organic, etc....) but some brake pad materials don't stop as quickly as others, or only work better after they are warmed up, it's a give-take for the ceramic ones with less dusting...etc. Also, slotted and cross-drilled rotors help to dissipate rotor heat better, but have less contact surface area than the same sized non-slotted/drilled rotors.

 

The rotors and pads are better that the stock ones and are the same brand and part number that I was using before changing them. I've tried again the car brakes and if I am testing them slowly they look soft but they brake OK. If its a harder braking, the peddal turns harder and seem to touch the bottom (hits something) and the car takes a very long distance to brake...
the fluid level looks to be in the middle of the min/max range

 

Can someone tell me what are the symptoms if the system is needing to be bleed.

Whats the procedure to do the bleeding.

Thanks
Regrads
RG

 

With a hard pedal there's not much air anywhere. Bleeding is always a good thing if done correctly and with only new fluid added, as it purges the most degredated fluid completely out of the car. Brake hydraulics love fresh fluid. Starting with a good firm pedal, I'd look elsewhere for the problem.

You said that they were bedded, how many miles on the new pads?

Take a piece of chalk and draw a radial line across both the inside and outside of each rotor. Now get the car going about 5mph and lightly apply the brakes to a stop. If the chalk line isn't completely erased where the pad wipes the rotor, they aren't bedded yet. I usually run a couple hundred miles before I consider brake system completely ready for action with new pads.

If by chance you used them hard already, the pads might be glazed, in which case there will be little friction between the pads and rotor. Remove pads and use a sanding block and abrasive to break the glaze.

The only other thing that comes to mind is the hardware. Did all of the pins look good, clean, and straight? Did the calipers have any float in or out when the pads were fully retracted? If there is anything inhibitingcaliper movement, pedal pressure will rise but the pad isn't clamping on the rotor. This will show up with the chalk, as it won't be wiped off that rotor.

I'm thinking the most probable cause is glazing of the pads, since it seems to be OK under normal and light braking. I'm not familiar with the brand of pad either but new pads and rotors should put you into the seat belts.

 

i got a 2002 audi a4 , this morning was fine but know in the evening when i apply the breakes it makes a weird sound like a klunk comingo from under the pedal or somewhere in there . they told me like 1 month ago that i need to change the rear brakes and they are making sound i want to know if there's any relation between the sound and my rear brakes .help please

 

i had the same problem and a brake bleed is a good place to start, you might need new fluid as well, motul 5.1 is great for daily drivers... however even those with stainless lines still didnt help me.. ended up being the pads... hawk ceramics suck!