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Help after brake job

acorazza

Go Kart Newbie
Location
NYC
Car(s)
2018 GTI 6MT
Hi all, I apologize if this is already posted somewhere but I didn’t have a chance to really search.

Just finished up a brake job: pads, rotors, lines, flush and when I jump in the car to throw the ebrake on it has no resistant and went straight to the top.

What did I do wrong and how can I fix it.

Thank in advance
 

acorazza

Go Kart Newbie
Location
NYC
Car(s)
2018 GTI 6MT
Ignore me. I think it’s working now. The brakes just needed to be pumped a little to bring the piston closer to the pads and not need as much pull on the cable. Can’t test it out yet because my battery also died so there’s that
 

acorazza

Go Kart Newbie
Location
NYC
Car(s)
2018 GTI 6MT
So I was able to go out for a test drive and the pedal travel is long. Longer than stock for sure. The pads are making full contact and wiped away all of the surface coating on my rotors (Zimmerman) but the car doesnt start braking until over an inch of travel.

I bled with a power bleeder so the fluid is fresh and shouldn’t have air unless I messed something up. I don’t remember if I depressed the pedal after doing the brakes to push the piston back after retracting them for the pads change but I think I did.

Is this normal for the Ferodo DS2500 to have bad initial bite? I haven’t done the full break in yet as the pedal travel honestly concerned me a bit. The car stops so I know the brakes are functional but they require a lot of pedal travel to make them work.
 

manu97

Autocross Champion
Location
Chicago
Car(s)
MK7 R
So I was able to go out for a test drive and the pedal travel is long. Longer than stock for sure. The pads are making full contact and wiped away all of the surface coating on my rotors (Zimmerman) but the car doesnt start braking until over an inch of travel.

I bled with a power bleeder so the fluid is fresh and shouldn’t have air unless I messed something up. I don’t remember if I depressed the pedal after doing the brakes to push the piston back after retracting them for the pads change but I think I did.

Is this normal for the Ferodo DS2500 to have bad initial bite? I haven’t done the full break in yet as the pedal travel honestly concerned me a bit. The car stops so I know the brakes are functional but they require a lot of pedal travel to make them work.


What PSI did you bleed at?
 

Acadia18

Autocross Champion
Location
The Greater Boston Metropolitan Area
Car(s)
2019 Golf R
That sounds like air in the brake lines.
 

acorazza

Go Kart Newbie
Location
NYC
Car(s)
2018 GTI 6MT
I bled at 2 bar with the motive bleeder but I think mine has a small leak and I have to see about getting a replacement because it kept losing a little pressure and I had to pump it up between corners. I think it’s leaking from the pressure gauge fitting. No leaks at any corner as I checked multiple times

I had each corner running clean which is why I didn’t think it was an issue.
 

YamR1rider

Drag Racing Champion
Location
Tampa, FL
Car(s)
2017 GTI Sport DSG
If you have got more pedal travel than before it does seem like you may have air in the system somewhere, but, you also need to bed those pads in properly. What I'd do in your situation is go and do a proper bed in to make sure its just not unbedded pads causing you to press harder. I'd also then go out and make sure to activate the ABS with a couple of extra hard stops to ensure fluid gets pumped through the ABS system. I'd then go back and rebleed the system working round all calipers.
 

acorazza

Go Kart Newbie
Location
NYC
Car(s)
2018 GTI 6MT
If there is air in the lines, should I be worried about the heat from bedding in the pads causing me to lose braking. That’s the reason I didn’t do it last night. I just didn’t have confidence in the brakes and didnt want to take a chance
If you have got more pedal travel than before it does seem like you may have air in the system somewhere, but, you also need to bed those pads in properly. What I'd do in your situation is go and do a proper bed in to make sure it’s just not unbedded pads causing you to press harder. I'd also then go out and make sure to activate the ABS with a couple of extra hard stops to ensure fluid gets pumped through the ABS system. I'd then go back and rebleed the system working round all calipers
 

YamR1rider

Drag Racing Champion
Location
Tampa, FL
Car(s)
2017 GTI Sport DSG
So long as you have enough travel to get stopped without the pedal bottoming out, I'd say go on some quiet roads and and bed the pads in first, simply just to save yourself repeating a step. You could go and re-bleed the brakes first...but if the pads are brand new the lack of feel for that first inch and perception you have to press harder might simply be because not enough pad material has yet transferred to the discs. Similarly, if there is some air floating about in the system I'd be tempted to go out and trigger the abs pump first just to move it through there (unless you happen to have VCDS and can trigger the pump). A non bled abs pump can be a common cause of braking sponginess.

Of course, if you feel like you are going to smash straight into a car in front of you say as the pedal and brakes are that bad....rebleed first, but know you may have to be back again for a third go round afterwards.

In summary, sounds like you've probably got a combo of air in the lines and brand new pads which could be making it feel worse than it is (if you are inexperienced as to how brand new pads on brand new rotors initially feel). Get one aspect sorted first, then the other.
 

DarkArrow

Drag Racing Champion
Location
OC
Car(s)
'18 R
In my experience, DS2500s have noticeably softer initial bite than OEM pads, but nowhere near an extra inch of travel in the pedal soft.
 

EpicTech

Autocross Champion
Location
Houston
Car(s)
MK7 GTI 6sp w/PP
Might need an upgraded bleeder block? I had this issue when I did the Macan swap. I also had to bleed the lines several times to get the pedal feeling good again. Now, I can tap my toe on the pedal and it will put your chin on the steering wheel lol.
 

acorazza

Go Kart Newbie
Location
NYC
Car(s)
2018 GTI 6MT
I’ve been driving the car around it feels a lot better now. Still need a proper bed-in. But it’s not that easy as I’m in NY and traffic kills that. I know a place that may work so I’ll try later but for now it’s much better. I’m also going to rebleed as I bought a new bleeder that hopefully doesn’t lose pressure and see if that helps.

I think my main problem was originally just the new rotor not having and friction material on it but they are starting to feel normal. The DS2500 don’t have a great initial bite but it should get better after the bed-in
 

acorazza

Go Kart Newbie
Location
NYC
Car(s)
2018 GTI 6MT
Brakes are feeling better. I also installed titanium shims. which I am debating on taking out. I feel like my brake may be dragging a little on the rear which is weird so I may start with removing shims on that end first to see if anything changes. I think they might be hanging up or something and the rear brakes don't work as hard so I don't think they are really needed.
 

acorazza

Go Kart Newbie
Location
NYC
Car(s)
2018 GTI 6MT
So I took out the shims a wile ago and re-bled the system with a new bleeder. Brake pedal is now good and firm and responsive. Only downside is that the Ferodo DS2500 pads have too much play inside the caliper and move around a lot. This leads to a fair amount of noise on bumps and rough roads where they rattle and clunk. I know this is by design so the pads can expand when hot but is there anything I can do to mitigate this and am I risking any damage to them or the calipers by having them clunk around.
 
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