Brake 'feel'

[Kezbo 0]

Hi

 

Got a '93 vr6 corrado. The brakes stop well but just dont feel convincing, ever so slightly spongy and the pedal travel is maybe abit long. Now im comparing them with my other car a '98 audi a3 and the brakes on that are awesome, really solid pedal and very little pressure needed to operate. Is it because its a newer car that i can feel a difference or could there be something up with the corrado's brakes?

 

BTW the fluid is new, discs and pads are used but no where near worn.

 

I guess its hard to give a definative answer without actually feeling them and comparing to another corrado but any tips would be v useful. Are there things that commonly go wrong? Thanks.

[bcstudent 0]

There isn't a standard Corrado on the planet with any feel to the brakes! I think it's normal, they're just like that :)

[Supercharged 2]

Kezbo, are you still running the mk3 rear calipers?? - Is the brake bias valve working ok?? this can have a serious effect on the brake feel...

 

Look at your rear disks to see if the rear brakes are working correctly - are they clean??

[Yandards 0]

Another thing to look it would be your flexi hoses.

 

If they are original they will be over 12 years old now and way past their best. Would be a good idea to change them for a set of braided hoses and that should give you some more feel back in the pedal.

 

But be aware that you are looking at a 12 year old system and aside from wear on the hoses there is also wear on all the rubber components within the braking system. I have replaced all the seals on my calipers and fitted flexi hoses and the brakes are firm and progressive. Only thing I have not changed/renewed the seals on is the master cylinder and I keep thinking about doing that too.

[Kevin Bacon 5]

I wouldn't waste money on a new Master Cylinder, particularly where the VR6 is concerned as it costs £170 (dealer only) and makes naff all difference, going by the car's Stealth have done this to in the past.

 

My brakes are kind of 'rejuvinated' with all new lines (copper and goodridge), new calipers, new pads, new disks, (Mixture of TT 312 and MK4) new fluid and a mega bleed session (ABS pump, calipers and MC etc) done by Stealth not long ago and it's as good as it can get. I feel it's still a bit mushy on occasion but Vince told me it's the best pedal he's felt on any Corrado, so it's definitely the car, and not a fault with the stoppers.

 

One thing I do notice is how rubbish the brakes are when the rears are seized. Yank the handbrake up and down at speed a few times to 'free off' stuck rear pads and see how the pedal feels then? Works for me :-)

 

I need to take the rears apart again and file the pad 'claws' down to stop them binding and rusting to the carriers.....happens every darn winter!

[Yandards 0]

I wouldn't waste money on a new Master Cylinder, particularly where the VR6 is concerned as it costs £170 (dealer only) and makes naff all difference, going by the car's Stealth have done this to in the past.

 

In that case then I won't bother, cheers Kev. :D

[Kevin Bacon 5]

:-) I think the G60/16V has a better pedal than the VR6 anyway but your MC only costs £45, so worth a shot if you suspect it's boogered.

 

There's something not right about the VR6 pedal. I think it relies on the rear calipers being 100% too much.

 

I read somewhere about pad 'knock off' which is where bumps and lumps cause the pad which isn't clipped to the caliper to move away from the caliper slightly, which causes an inconsistent pedal as the caliper has to first take up the slack before the brakes bite properly. It's more of a problem with floating calipers than Brembo type ones.

[Kezbo 0]

Cheers guys, i think everything in the brake department is as it left the factory so a brake refurb is probably due. Is it worth replaceing calipers etc with existing or are there any good / worth while upgrades around - i heard something about 288 front discs off a mk4 golf? What about the rear. Im running standard 15'' wheels so size is abit limited.

[james_88 0]

I know what you mean, the brake pedal does have a bit of travel compared with newer cars! Think the vr6 does have a longer pedal travel, i was driving my mates vr6 at the weekend and it has a longer travel than my G60!

[Kevin Bacon 5]

Yeah the VR6 pedal is scary at first if you're not used to it!

 

288s, good those. Audi TT 312s even better :-)

 

Rears are quite limited caliper wise, but MK4 rears are better than the standard MK3/MK2 calipers. Just make sure you file down the pad claws slightly to prevent them binding to the carrier.

[PhatVR6 0]

I could never understand why my dad's mk2 TDI had so much better brake feel than my corrado, when they were both using the same calipers and mine had braided hoses with fresh fluid and I'd bled them to death!

 

I'm hopinh my new caliper setup doesn't kill the feel as now I'm used to driving my onwn mk4 daily and they bite they have feels great (althoughI have managed to out-brake myself a few times, (the 312's aren't that good with 1550kg to haul up)

[Kevin Bacon 5]

I don't think you'll have much of a problem with Porsche/Brembo calipers ;-)

 

There's just someting inherently cr@p about VR6 brakes. Not even Vince can put his finger on it. MK4 brakes use a different servo/MC and ABS setup as I'm sure you're aware. I'm sure Jay's brakes are miles better than ours.

 

312s suffice with 1250Kg to stop....just 8)

 

I really need to get some proper alloy calipers on there, too much to choose from.

[PhatVR6 0]

I just hope the master cylinder is going to be big enough?

[Kevin Bacon 5]

Well the VR has the biggest MC of all Corrados at 23 or 23.1 mm (might be why it's so expensive?). There's a funny equation I can never remember about MCs. Something along the lines of the bigger the MC bore, the less effort you need, but gives more travel.

 

Best thing to do is try your Porker calipers and see what the pedal is like. You can always do what Jay did with the MK4 stuff if you're not happy.

 

Interestingly, even 911s have a slight deadness on the initial pedal travel....you need to jump on the pedal to get that famed "brick wall at 100mph" feel....

[PhatVR6 0]

Mine still has the original 8v MC! haven't even looked at the size of it, but it was good enough to all but melt the 288's.

[Kevin Bacon 5]

LOL! I think the 8V MC is 22mm, so in theory it should give better inital bite and less travel, but from high speeds, there might not be enough pressure. That's where the 23mm MC comes into it's own. It's a bit dead at low speeds, but stamp on it at 100mph and the brakes work well.

[mgbv8mike 0]

I have an MGB with Rover V8 brakes (long story...don't ask)

 

The MG pedal travel increased substantially when I did this mod......it's very similar to my VR6, and frightens people when they first drive it....but like the Corrado it stops excellently....modern cars have far too sensitive pedals IMO, I nearly put a passenger through the screen in a Mk4 Golfy the first time I drove one in anger ( and the power steering was far to much.....though I wish the MGB had it sometimes.....no fun parking with 195 tyres and no assistance)

[Roger Blassberg 0]

A larger diameter master cylinder will require a higher brake pedal force for a given system pressure (pressure is force per unit area, so the greater area requires more force to develop the required pressure) and a shorter travel, whilst a smaller diameter will require a lower pedal force and will give a longer travel. Elementary my dear Pascal.

 

Happy new year

 

RB