Brake upgrades

[Stuwey]

Hi all, I've just fitted my TT-spec brakes to my GTI. Sure looks the goods. I'm running the RDA slottetd type rotors. New ones at that.

Bought the calipers etc off another forum member, and all fitted up well.

Question though. Brake pedal feels alot less 'firm' than what it used to (yes, its been bled properly) and the take-up point is alot further down on the stroke of the pedal. Under hard braking you can also feel the car is a heap more 'taily' and alltogether less sure-footed than it once was. Not just JUMPING on the pedal at 80 klicks, but morethe gradual making-the-car-stand-on-its-nose kinda stop you'd have pulling up for the Northern Hairpin at Mallala.

Now, the pads i'm using are the second-hand EBC Red Stuffs that came with the calipers and they look to have been... lets say "heated" once or twice.

Many of you lot on this forum run this brake setup, have you experienced the same?

New, fresh pads?

Go for a blat and bed 'em in harder?

Any help would be appreciated.

Cheers

[h100vw]

I'd give them a bit longer to bed in.

Pads having been well used before, wouldn't bother me. If you didn't get them on the same disc face they came off, they'll need to bed in again.

If you are stomping on those big brakes, the weight transfer to front would make the back end feel light.

Gavin

[firdausasri]

Stuwey,

Are you using TT brake master pump? You need bigger brake master pump to cope with bigger calipers upgrade. Unless, there's some leak in either in rubber hose or right or left caliper pump. But then you should see that brake fluid level is lower the more you drive it

[h100vw]

Do you mean the Master cylinder?

Gavin

[Stuwey]

Bedding in will continue for the next few weeks or until i feel comfortable with the pedal feel i'm getting.

brake master pump

Master Cylinder, or Booster?

I had wondered about the hydraulic difference required with the larger piston in the TT caliper.

[h100vw]

Larger piston will have more volume, so need more fluid.

Has this issue not cropped up before, if other have done the upgrade? Will the std calipers not go over the 312s?

Gavin

[Stuwey]

Larger piston will have more volume, so need more fluid.

Has this issue not cropped up before, if other have done the upgrade?

Exactly what I had thought. SURELY i can't be on my own on this one.

[h100vw]

Mk4 Golf or A3 would probably be the go. I had 312s on the A3 and they were OK and the pedal wasn't long.

Gavin

[firdausasri]

Oppps, sorry I meant Brake Master Cylinder. You need more supplies of fluid pressure from it to cope with uprated calipers. But then, if TT have the same BMC as per ours, then I was wrong.

[Stuwey]

Great. The "easy" upgrade turns to ***** once again...

[h100vw]

Great. The "easy" upgrade turns to ***** once again...

Don't give up easy mate!

Gavin

[Stuwey]

Well, you're not far from me, i'll be in touch!

[h100vw]

Please do doing a special this week on chips and master cylinders!

Gavin

[MACCAA]

Stuwey,

Are you using TT brake master pump? You need bigger brake master pump to cope with bigger calipers upgrade. Unless, there's some leak in either in rubber hose or right or left caliper pump. But then you should see that brake fluid level is lower the more you drive it

No you don't.The standard master cylinder is the one used by everyone I know using this set-up.
Just run the brakes for a while and let the pads bed to the discs.Chances are they're not in the same position as when last used.
Also,another bleed could help.
It would be nice if people,who although well-meaning,don't throw up comments that are way wide of the mark re the above.
Once sorted,there's no problem re "lightness" at the rear under heavy braking on the track.
Stuwey now thinks he has a problem,when in fact he doesn't.
Stick with it Stuwey.It's probably one of the things I've mentioned.
Cheers
Len

[h100vw]

What's the difference in the calipers then Len. How come you need the TT ones?

I expected Polo brakes to be the same as my A3, 288x25.
Gavin