# Soft brake pedal after 312mm 254mm TT brake upgrade (NO AIR IN SYSTEM)



## foffa2002 (Jan 14, 2003)

I just changed my brakes to a full (front and back) audi TT upgrade on my jetta/bora mk4 and ive checked the fluid for air and my lokal Vw dealer didnt find any either and everythings ok BUT the pedal feels a bit soft








What can have gone wrong.. and my friend didnt make me kless confused when he told me that i have to use a vag com to adjust the ABS








Another told me that TT got a bigger "slave cylinder" then my car and thats why i get a softer brakepedal








The brakes works fine but i dont have the respons that my friends got on their Mk4 jetta´s

What should i do??????


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## dcomiskey (Mar 13, 2002)

*Re: Soft brake pedal after 312mm 254mm TT brake upgrade (foffa2002)*

Your problem is the ABS. I had the same thing after getting new fluids and lines a couple of weeks ago. The ABS needs to either be reset or activated. See if you can find an icy or slippery spot in a parking lot and hit your brakes to active tha ABS. Your soft pedal should disappear after that. It has nothing to do with your "slave" cylinder (whatever that is).


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## foffa2002 (Jan 14, 2003)

*Re: Soft brake pedal after 312mm 254mm TT brake upgrade (dcomiskey)*

I will try to find a ice spot to activate the ABS..it wont be a problem to find one..cause i live in sweden.
I tell you if it works in a couple of minutes


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## FlashRedGLS1.8T (Apr 17, 2001)

*Re: Soft brake pedal after 312mm 254mm TT brake upgrade (foffa2002)*

What he said!
Engage the ABS.


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## foffa2002 (Jan 14, 2003)

*Re: Soft brake pedal after 312mm 254mm TT brake upgrade (foffa2002)*

didnt work..i even tried to reset the system by disconecting the battery for 20min 
will go to my friend tomorrow and try to reset abs with his vag-com


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## bluevr6 (Apr 19, 2000)

*Re: Soft brake pedal after 312mm 254mm TT brake upgrade (dcomiskey)*

Slave cylinders are used to transfer pressure to mechanical action.
Think hydraulic clutch mechanisms.
--Kevin


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## Electron Man (Sep 21, 1999)

*Re: Soft brake pedal after 312mm 254mm TT brake upgrade (foffa2002)*

quote:[HR][/HR]...my friend didnt make me kless confused when he told me that i have to use a vag com to adjust the ABS[HR][/HR]​Did you remove brake lines from either of the four calipers? If so, you probably still have air in the system. Use the VAG COM to run the ABS pump (must have some air trapped somewhere to have a spongy pedal).
Pedal shouldn't be spongy if you didn't open the hydraulic circuit.
edit: If you have to bleed the brakes by pumping the pedal, only push it about 1/2 to 2/3 of the distance to the floorboard. If you press pedal too far, MC seals could be damaged. (New ABS MC is $$$)


[Modified by Electron Man, 4:51 PM 3-11-2003]


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## Racer_X (Jul 14, 2002)

*Re: Soft brake pedal after 312mm 254mm TT brake upgrade (Electron Man)*

I agree with electroman here. 
Also, if you replaced or disconnected the rear calipers, you might need to pre-bleed the rear calipers. I'm not 100% sure on this because I haven't worked with the newer brake systems. With the older A2's, the rear calipers are designed (poorly) where it's possible to get air trapped in the caliper above the bleed screw. With those, you remove the caliper from the carrier frame, point the piston straigh down (and the bleed screw straight up), attach a clear hose to the bleeder and open it. *Don't pump the pedal*, just let gravity pull the fluid and air through until no more air bubbles come out. Then, close the bleeder and mount the caliper again. You still might need to bleed it one more time after you install it.


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## foffa2002 (Jan 14, 2003)

*Re: Soft brake pedal after 312mm 254mm TT brake upgrade (Racer_X)*

Thanks for all the help..
I went to VW today and talked to som mecanics and they didnt have a clue







..BUT
i later went to V.A.G head office (1km from C-lab=my work) and talked to a man that said that this was a common problem with ABS and the education at vw service stations could be better...
So now i they know what to do...They have to use the diagnos1551 tool bleed the abs unit and do the bleeding of the brake system all over again.
its a 16 step procedure that requires vag tool for abs and equipment for the brakes.
I hope they do this the right way this time







.....it feels like teaching them how to do their job









vw vortex crew http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif


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## dcomiskey (Mar 13, 2002)

*Re: Soft brake pedal after 312mm 254mm TT brake upgrade (foffa2002)*

Funny. It seems these supposedly certified techs don't know what the f they are doing. Mine obviously didn't have a clue either. And to me this seems fairly routine. http://****************.com/smile/emthdown.gif


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