CB Performance NEW DISC BRAKE noise?

[jacoby1007]

Hello,

I searched for this topic but didn't see it. I installed a new CB disc brake kit on my rear only and notice an increase in road noise. It sounds like I just got new mud tires. I am almost 100% that it wasn't this loud before. Did anyone else notice this or do I have another issue? I also changed my tires around to make sure they are spinning the same direction.

Also my pedal touches the floor even with the residual pressure valve installed. David at CP told me to bleed them again starting with the front right then FL then BR, BL. I will try that soon.

I went with CP to replace my old EMPI disc setup that came with the car. They would hum nice and loud when cornering or stopping. Much better already with the rears replaced!

Tires are also new around 700 miles on them.

[rockerarm]

Hi.
Regarding the low brake pedal, it could be a few things.
1- Air still in the system. There are a few methods of bleeding. Hose into a bottle, two person bleed by pump up hold open bleeder, pressure bleeder, and gravity bleed (drip). Are the calipers in correct position with bleeder on top? Can you view the brake pads as they should be very close (feeler gauge close) to the rotor surface.
2- A failed master cylinder. It happens. Sufficient pedal to master cyl freeplay?
3- Too small a master cylinder to "move" all the brake fluid needed to push all 4 caliper pistons. You do have a 4-wheel disc brakes now? I believe the fix is the larger dia master cyl, about 20mm dia.
Are you using the standard industry DOT 3 or 4 brake fluid, and not that silly DOT 5 silicone fluid?
In order to minimize brake pedal travel you might consider the stainless braided flex hoses at all 4 corners.
Hope this helps, Bill.

[jacoby1007]

Thanks Bill, I will give that a try tonight. Standard fluid in my setup. All 4 disc brakes, the fronts are EMPI that will be replaced once I save a little for them.

The back tire noise is driving me crazy. I am going to put it up on stands tonight and see how it sounds when I spin the wheels. Its weird how it got loud after adding these new CP brakes.

[rockerarm]

Hi.
There are a few folks here on the early type 1 and later type 1 sections who have a vast amount of experience with a 4-wheel disc brake set-up. There are only so many set-up's available, I guess. I will try and get you some better info on this.
Odd, that the noise appeared after brake parts installed. Yeah, jack it up and inspect, remove the load the tires apply to the ground. Does your car have the original 5x205 lug pattern wheels or the later 4x130 pattern? I may have the later wheel/tires to swap and road test, if you have the 4x130's.
Let me know if you need a second opinion.
Bill

[slalombuggy]

Take your calipers off and look for rub marks on all the parts. It sounds like something isn't centered and is rubbing. Either the rotor is rubbing on the caliper or bracket. For bleeding rear calipers, I usually take the caliper off, put a 3/8 spacer between the pads, and bleed them holding them up as high as the line will let me. Them I attach the park brake cable.

Nothing wrong with DOT5 fluid. I've had it in my cars for 8 years, no ill effects. My cars sit for long periods of time so hydroscopic brake fluid is a problem.

The brake noise on the empi brakes was probably from the caliper bracket being just slightly off parallel from the rotor. I've found that on 2 sets I've installed. It was an easy fix with a pry bar, but now I just use the heavy duty bracket instead of the stamped one.

brad

[jacoby1007]

Thanks for the feedback! I fixed the pedal issue tonight. Bled the brakes tonight front to back and it stops great now!

CB Performance asked me to take lots of pics of the setup. I sent them a video also (see below), hopefully they will have some advise.

When it was on the stands I put it in neutral and spun the back rotor and it would spin to a spot then stop. Seems like it is a little off or something is bent, or maybe thats the way they are. I am new to most of this but I am guessing thats where my noise is coming from. Link to video below.

https://www.dropbox.com/s/asx4ghsc93nfvgf/2016-12-14%2019.44.12.mov?dl=0

[jacoby1007]

Oh also the EMPI brakes I had was because of that issue as well. I did some searching on here and CB seemed like the best option that was in my price range.

[jacoby1007]

So I tried what CB told me to do, still sounds the same. I am wondering if the transaxle (that I am eventually going to replace due to some issues) is where my noise is coming from. Video below with the brakes off and me spinning the hub. Does that sound normal or is mine loud?

https://www.dropbox.com/s/zn0v9sppbh3l461/2016-12-17%2016.41.44.mov?dl=0

[slalombuggy]

The brakes sound fine. Have you put many miles on them? Disk brake pads will drag on the rotors a bit and can be louder than drum brakes. Spinning one hub creates a lot of noise in the transaxle as the differential and spider gears knock around a bit.

brad

[jacoby1007]

Thanks, either way I need to replace/rebuild my trans and someone told me it is loud compared to one in better shape. That will be my next big item. Going to go with Rancho.