Hey guys I'm having some brake problems. I just installed stoptech BBK in the front and now when I'm driving it feels like the brakes are stuck slightly even though I'm not stepping on the brake pedal....... I brought my car to the shop today but they didn't know what was wrong so they said they took off the whole brake system and adjusted it. My brakes were working fine but the brakes got stuck slightly again after two hard braking..... Can somebody help me out here please... Is it the brake pads?? Master cylinder??? Thanks in advance

Mike

 

Brake pads are OK.
Assume that the piston is NOT hanging up inside the calliper: they are new brakes.
Only thing left is the master cylinder. Which is troubling because the cylinder was functioning properly before the install.

 

Did you follow the manufacturer's pad bedding instructions? If you don't have the directions, simply Google it and follow the steps. This is normal, my brakes felt like they were dragging, or somewhat engaged but they weren't.

 

Ya, I did followed the pad bedding instruction. I also did it again today just in case but I still have the same problems...... So I'm guessing it has to be the master cylinder then??

 

What stoptech kit and on what year 350Z? Also, can you explain how you know it feels like the brakes are still on? Did you do a front only or a front and rear BBK? What pads? Did you install anything between the pads and the pistons like titanium shims? Was the complete kit, rotor's, calipers, pads from Stoptech? Did you install it or someone else?

Just trying to get a really detailed explanation of your complaint to help troubleshoot it.

 

So here's some things to check:

1) When the pads are installed into the caliper they should slide in fairly easily. So, when the pistons are pushed up into the caliper new pads should slide in freely but be a bit snug. I've seen some of the pads which have what looks like a mesh fabric on the back of the steel backing fit fairly tight in the caliper. This means the pad thickness seems almost the same maximum width allowed by the caliper with the pistons compressed fully. This should loosen up as the pads wear.
2) The pad length will some times have some flashing from the stamping die. The Stoptech calipers that I have, have steel wear plates in the caliper. Sometimes it looks like when they stamp out the pad is tears and leave a big burr on the pad. The pad then can be really tight in the caliper. Just file this off or take off this flash until it slides in the caliper. Don't grind off too much, you don't want the pads having a sloppy fit in the caliper.
3) Worse case, you've got a piston hanging up in the caliper which seems highly unlikely. I would think if your brakes are truly stay on and dragging constantly you are going to fry the pads and the rotors. There isn't anything to adjust so something doesn't make sense.
4) Are you sure the calipers aren't hitting your rims?
5) Did anyone mess with your parking brake adjustment? Is it really the rears dragging?

Hope this helps.

 

Did you buy the kit new or used?

 

I only got the front BBK. Ya it's the complete kit from Stoptech. It's ST-60 caliper with 355X32mm rotor. I have no idea what kind of pads i got... and I had someone else installed it for me because I've never done it before and I felt like I'd kill myself if I don't install it right lol. It feels like the brakes are on because usually when i release the clutch just a little bit my car would start moving but now i have to give it some gas. And you know if you park your car on a hill, and you step on the brake pedal just a little bit and the car's rolling even though the brake pads are touching the rotor but don't have enough force to stop it and makes the sound??

 

I bought it new

 

Oh and I got 04 touring if that helps

 

Did you cut off the dust shield?

 

when you say getting stuck, what exactly does the car feel like when this occurs?

often times adding a BBK can create a different off-braking feel in general due to the fixed caliper design.

 

I thought with the BBKs you had to change the master cylinder? Min. is at least change it out to an 06.

 

No, not required for most off the shelf BBKs out there for these cars.
I've researched this idea out quite a bit when I had stoptech 6 pots on my 04 Z, but found that it's not required and not quite beneficial either. Besides his Master cyl was working correctly prior to the brake install. I clocked over 50K miles on my Z with my stoptech BBK on it, original master cylinder and ABS etc, no problems in all that time. And I wasn't exactly kind on them either.

 

So I've tried almost everything (bled the brake, checked the master cylinder and adjusted the whole brake system) but I still have the same problem.......
I called Stoptech today and they told me the only possibility they can think of is that I have unbalanced brake set up which makes sense to me (6 piston 14inches in the front and tiny stock rotor with 1 piston in the rear). They suggested me to get 4 pistion 14inches BBK for the rear. Does this sound right to you guys?? Do I really need 4 pistons/14inches rotors in the rear??

 

No,that doesn't make sense to me. Seems like you must have something mechanically binding or something is keeping the pressure from relaxing when you take the foot off the brake pedal. Here's some more thoughts:
1) Jack the front off the ground so both wheels can spin.
2) Spin the wheels and see how much force it takes to spin them. Should feel a slight drag.
3) Pump the brake pedal a few times and release.
4) Now check the front wheels for freedom of rotation. If after pumping the brakes it takes a huge force to rotate the wheels I would think something is keeping the pressure from relaxing.
5) If #4 shows a lot of resistance, You could then open a caliper brake fluid bleed screw. Without touching the brakes after you pumped and released them. If a bunch of brake fluid squirts out then I would think something is binding in the master cylinder. Maybe contamination is causing the master cylinder to stick and hold the pressure? If the fluid just gravity drains out then it's not retained pressure causing the issue.
6) You could repeat this process with the rear jacked off the ground. If the rears don't bind after pumping and releasing then it is something in the caliper/rotors of the front. If the rears bind just like the front then I would think something is keeping the pumped up pressure from relaxing as it should.

So, try that...that should isolate the issue.

 

There are thousands of other Z owners out there running just a front BBK with no problems.

 

Ok I'll try it tomorrow thx

 

But I have never seen someone with only 6 pistons in the front and stock in the rear though?

 

Also I just realized it starts dragging when I press the pedal hard not when it gets hot... any suggestions??