RS4 Brake Upgrade issue.

[Inertiauk]

Ok, so I have a B6 S4, and the brakes are shockingly bad on it, so when it came ti time for new discs and pads, I opted to buy some used Front RS4 Calipers, discs and OEM pads (discs have 0.01mm lip, hardly even feel able, pads are audi OEM and have around half their life left)

I kept the standard wheels using 10mm spacers.

I used my mechanic (Lees garage Royton, VAG specialist) to fit them.

I expected a massive improvement, but tbh, I'm not even sure there is any improvement in braking. The brakes feel a bit soft, so to get them to work well you have to move the pedal a fair bit further down than you used to and I guess if you press it quite hard they are slightly better, but I was expecting a major improvement with brake feel and it to bite with the pedal pressed sooner rather than at the bottom.

My mechanic has bled them up properly, he is a professional and does this kind of thing day in day out, so I tend to believe there is no air in the system ? Or am I wrong ?

I'm wondering if I should get brand new Brembo or EBC pads and even possibly new phaeton discs to sharpen them up ?

Or are there other components needed from the RS4 to match the brakes to make them work properly, such as master cylinder, or ABS pump, or something ?

Any help is appreciated.

Thanks
Mark

 

[AlexGSi2000]

To be honest, I was under the impression that the S4 brakes are very good for what they are.
I upgraded my 312mm's to S4 brakes - the difference was night and day.

If I remember correctly, the pedal feel will be more "sudden" with a single pot caliper, and less with a caliper with multiple pistons - in this case the RS being a 4 pot.

The advantage with a 4-pot calliper is the spread of the load on the pad it will perform better at higher speeds and temperatures as opposed to a single point on a single piston caliper.

Are the brake servos the same siza on the RS4? May not be pushing as much fluid round the system as opposed to an RS4 servo?

 

[hades-]

the servo dont need changeing when rs4 are fitted
what gets me thinking is you say the S4 were crap and the rs4 not much better
there must be something wrong as the s4 are very good anyway
and the rs4 even better
one thing i wouldnt have done is use second hand pads

 

[quattrojames]

what gets me thinking is you say the S4 were crap and the rs4 not much better
there must be something wrong as the s4 are very good anyway

This was exactly my first thought.

 

[dpbayly]

When you say the S4 brakes didn't perform well Im guessing it had a good pedal not spongy if it did then here's my thoughts.

The B6 S4 runs the same brake master cylinder as the B7 RS4 so there is no need to change that and the difference between the caliper piston surface area is as good as the same S4 caliper has a piston surface area of 2827 mm² and the RS4 8 pots have a surface area of 2839 mm² so the pedal should feel exactly the same as it did before only difference should be less force on the pedal is needed to be applied to achieve the same braking effort due to the higher leverage the calipers have on the larger disc and more friction area due to larger pad surface area which is why more pistons are needed to spread the pressure evenly across the larger pads.

So with all that said if you had a good solid pedal before(not talking about brake performance) then the problem giving you a spongy pedal lies with either they have not been bleed correctly and there is air in the system or its down to running second hand pads on second hand discs if the pads have not been installed as they were removed ie n/s inner and outer (in the rs4's case also upper and lower as they run 4 pads a caliper) then they will not be bedded in and will be flexing ever so slightly as the pads wont be touching 100% of the disc surface, sometimes the pedal feels a little spongy for a short time after fitting new pads to old disc till they bed in so same principle could apply to you if not fitted as they were removed and as there is more pad surface area it will amplify the spongy feeling.

I would start with checking they are bleed correctly when i fitted my 8 pot set up a couple of weeks back i bleed them inner nipple then outer then inner then outer that seemed to work well even the second time on each nipple i still got air out even though the first time round i bleed till no air could be seen coming out.

My pedal on my 8 pot set up is spot on no spongy feeling and very responsive.

Good luck with sorting it and get some pics up.... also out of interest what size discs do they run on?

 

[Inertiauk]

Thanks for the reply's guys, and sorry I haven't been on in a week, been busy.

I was just impatient I think. they have go t a lot better over the last 500 miles as they have bedded in.
The pads have been moved so that would explain some of it, but bedding in has made a huge difference and i'm now pretty happy with them.

The discs are in good shape, so my plans are in a few weeks to order EBC yellowstuff pads as they are well rated and not as expensive as other good ones. And also get some high temp brake fluid and have it bled through completely to be sure everything is optimal.

DPB ... The discs are 365mm.

Pics ..

S4 Single Pot Brake ...


Grinding the Guard...

8 Pots Fitted ...

Wheel on ...

 

[dpbayly]

Glad to hear you sorted it, my initial thoughts were a bedding in issue.

I'm running yellow stuff with my 8 pots and they work very well

 

[AlexGSi2000]

Wow, they look amazing. Glad they have settled.

 

[marktdisport]

Strangely my S4 brakes was perfect on my B6...... Very over powering to be honest....

But those RS4 look amazingly nice

 

[Inertiauk]

Strangely my S4 brakes was perfect on my B6...... Very over powering to be honest....

But those RS4 look amazingly nice

Granted towards the end they needed discs and pads so they were terrible, but even when they were in good condition, they were **** poor.

Its a heavy car capable of hitting big speeds fairly quickly, plus capable of carrying quite a few passengers adding to the weight. Mine has a little more power than a stock S4 due to Full Miltek (inc cats) and a Custom Code VVT attack stage 2 map. However I still don't think the stock brakes are good enough for the stock car.

I remember one time having a play with an Evo, there were a few of us in my car, I needed to stop from 80, fairly quickly, it didn't really happen, the brakes felt useless from that speed with the extra weight.

It was from that day I decided they needed upgrading.

However now these RS4 brakes are bedded in, They are up to the job and Im happy

 

[Andie0]

Quick question i tracked lydden hill today and my standard brakes on my 1.8t s line are shockingly bad and were smoking like crazy afterwards! Brake fade isnt the word to use... I was thinking of the rs4 upgrade is this possible on mine? Thanks... Sorry to bust in on your thread like this but didnt want to start a new one when the topic of rs4 upgrade is here thanks alot

 

[Inertiauk]

Quick question i tracked lydden hill today and my standard brakes on my 1.8t s line are shockingly bad and were smoking like crazy afterwards! Brake fade isn't the word to use... I was thinking of the rs4 upgrade is this possible on mine? Thanks... Sorry to bust in on your thread like this but didn't want to start a new one when the topic of rs4 upgrade is here thanks alot

Yes they will fit but you need at least 18" wheels, and if the offset is higher then ET38 then you will need wheel spacers.
I'm not certain if your master cylinder would need changing to match, someone might be able to confirm this ...

 

[Andie0]

Yes they will fit but you need at least 18" wheels, and if the offset is higher then ET38 then you will need wheel spacers.
I'm not certain if your master cylinder would need changing to match, someone might be able to confirm this ...

Thanks i will get purcjasing i have 18" rs6 wheels on there already... Would be great if someone could confirm as i plan to track often and like to be able to brake as im doing 100 into them bends lol...

 

[Andie0]

Can anyone please let me no exactly what i need for this upgrade?

 

[Inertiauk]

Probably get these used as a set ...

RS4 Rotors 8E0615301AB
RS4 Calipers 8E0615107 and 8E0615108
RS4 Pads 8E0698151Q

You will need ..


RS4 Brake Lines 8E0611707H X2
RS4 Mounting brackets for ABS and pad sensor wires 8E0615133G & 8E0615134G
RS4 Small brackets, these secure the brake line at the caliper 4B3615133D & 4B3615134D

You will probably need
RS4 Dust shields 8e0 615 311D, 8E0 615 312D On an S4 they are big enough and I was able to modify them to work, I doubt yours are.

You may need A Master cylinder upgrade too, One from an S4, S6, or RS4 will do the job I believe the one you have might even be good enough, sorry I cant advise further on this aspect of it.

 

[Andie0]

Theres a shopping list.. I am definetly wanting to stop better how was the s4 brakes on your car inertia? Was they useless is that why you upgraded, just to comfirm these parts are all from b7 rs4? Thanks

 

[Inertiauk]

Theres a shopping list.. I am definetly wanting to stop better how was the s4 brakes on your car inertia? Was they useless is that why you upgraded, just to confirm these parts are all from b7 rs4? Thanks

I wasn't happy with the S4 brakes at all, others have said the opposite above, but I think they were **** poor, but then your car has less power and a fair bit less weight than mine, they might be fine for yours.

Parts I listed are from a B7 RS4.

 

[marktdisport]

I wasn't happy with the S4 brakes at all, others have said the opposite above, but I think they were **** poor, but then your car has less power and a fair bit less weight than mine, they might be fine for yours.

Parts I listed are from a B7 RS4.

Just out of interest could you of had a poor pad issue as when I sold mine my uncle drove it and couldn't live with how sharp they was so I removed them and swopped it back to std 288mm for the big sale, I drove mine pretty hard and never once felt they wasn't good enough to stop me on a penny it was running pagid disks and pads