New Car Brakes

bobcowan · #1 (**permalink**) 10-01-2018, 10:36 PM

Just got my car back from the engine tuners. Drove it for the first time today, and it runs awesome.

But, the brakes are terrible! You need a lot of pedal pressure to slow the car down. and there's not much pedal movement at all.

The car is brand new, with power brakes. I did not opt for the Wilwood brakes.

I'm hoping that they just need to be bedded in properly. I hope.

Any thoughts?

Trubble · #2 (**permalink**) 10-02-2018, 07:55 AM

Bob,

I've seen discussions on this topic somewhere in the forum. Try using the "advanced search" tool, and I'll bet you will find some good info.

Good luck.

jeffnolan · #3 (**permalink**) 10-02-2018, 09:06 AM

Excessive pedal pressure won’t be resolved by bedding in. Brakes and steering are two systems I never rely on hope for.

jeffnolan · #4 (**permalink**) 10-02-2018, 09:08 AM

Delete (duplicate)

cycleguy55 · #5 (**permalink**) 10-02-2018, 11:07 AM

Quote:

Originally Posted by bobcowan

Just got my car back from the engine tuners. Drove it for the first time today, and it runs awesome.

But, the brakes are terrible! You need a lot of pedal pressure to slow the car down. and there's not much pedal movement at all.

The car is brand new, with power brakes. I did not opt for the Wilwood brakes.

I'm hoping that they just need to be bedded in properly. I hope.

Any thoughts?

Yes, the brakes will be terrible if they haven't been bedded in!

I replaced the 9" Mustang II / Pinto front disc brakes with Wilwood 4 piston calipers and 11" rotors, and the rear drums with a GM single caliper set. When I first drove it down my street (at a very low speed) I thought I had NO brakes. Wow - just nothing there. Even with the power booster it took ridiculous pedal pressure to slow it down. I persevered, though, making repeated HARD applications and improvement was obvious and fairly quick. It was only after I took it out on a nearby secondary highway and went through the recommended routine to bed the brakes in that things really improved.

I followed a similar bedding procedure on my daily driver when I replaced the pads, and the same on my wife's daily driver when I replaced the pads and rotors - to the point where I had wisps of smoke coming out of the front wheel wells. Properly bedded pads and rotors work so much better it's scary. My DD went from good to incredible.

Wilwood's "Pad Bedding - Tech Tips": https://www.wilwood.com/techtip/techpadbedtip

Wilwood Brake Pad And Rotor Bedding Steps: http://www.wilwood.com/Pdf/Misc/Pad_...ding_Steps.pdf

cbreez · #6 (**permalink**) 10-02-2018, 04:03 PM

Quote:

Originally Posted by bobcowan

I'm hoping that they just need to be bedded in properly. I hope.

Any thoughts?

Unless you are going to drive 10 tenths, out of the box, don't worry about bedding brakes on a 2400 lb car. The factory bmw brakes on mine worked fine under track day conditions with cheap pads...don't over complicate things. JMHO

pm125 · #7 (**permalink**) 10-02-2018, 05:33 PM

I installed the Wilwood 14 inch front rotors with 6 piston calipers in front and the 12 inch in the rear with 4 piston calipers. These brakes are kiss the wheel brakes, excellent.

bobcowan · #8 (**permalink**) 10-02-2018, 08:43 PM

This car is a street car only. Just for fun. But, being a racer, I really want good brakes. These don't seem to work as well as my truck. For power brakes, they really are disappointing.

When I get time I'm going to check the vacuum line. I'm wondering if there just isn't enough vacuum to run the brakes. Makes me wonder if I can simply add a big reservoir, or if I need a pump and reservoir.

jhv48 · #9 (**permalink**) 10-02-2018, 10:18 PM

Is the car an FFR? The reason I ask is because you list your car as a FFR with a 427, but placed the thread in the Backdraft racing section.
Do you now have a backdraft cobra?
What vacuum are you pulling with is engine?
A low vacuum pulling engine can greatly reduce the effectiveness of power brakes that depend on engine vacuum for full effectiveness.

cycleguy55 · #10 (**permalink**) 10-03-2018, 11:39 AM

Quote:

Originally Posted by bobcowan

This car is a street car only. Just for fun. But, being a racer, I really want good brakes. These don't seem to work as well as my truck. For power brakes, they really are disappointing.

When I get time I'm going to check the vacuum line. I'm wondering if there just isn't enough vacuum to run the brakes. Makes me wonder if I can simply add a big reservoir, or if I need a pump and reservoir.

If you're not running a reservoir you should add one. Don't forget a proper check valve(s) to hold vacuum in the reservoir.

Article here on installing a vacuum pump, including diagrams showing check valves: https://www.powerperformancenews.com...acuum-booster/

bobcowan · #11 (**permalink**) 10-03-2018, 08:05 PM

Quote:

Originally Posted by jhv48

Is the car an FFR? The reason I ask is because you list your car as a FFR with a 427, but placed the thread in the Backdraft racing section.
Do you now have a backdraft cobra?
What vacuum are you pulling with is engine?
A low vacuum pulling engine can greatly reduce the effectiveness of power brakes that depend on engine vacuum for full effectiveness.

Good point! The FFR burned two years ago. I'm working on a
Backdraft now. I forgot to change that. In all this time, you're the first one to notice.

I was going to use a reservoir. Cheap, simple. But, there's almost no vacuum at the port. I was afraid that if I needed the brakes a lot, like stop and go driving, I'd run out of vacuum. I ordered a vacuum pump from Master Power Brakes.
https://www.mpbrakes.com/accessories...m-pump-kit.asp

bobcowan · #12 (**permalink**) 11-01-2018, 07:15 AM

Turned out to be a bad booster. Another new part needs to be replaced. That seems to be the theme for this car.

The replacement is a Porsche part, slightly bigger than what's in there. The pedal rod has to be threaded and shortened to fit.

Getting it in there was a PITA. Had to remove the steering column, valve cover, and side louvre.

Now the brakes are really good. Not pop your eyeballs out good. But really good. Maybe I'll switch to a more aggressive pad.

KDubU · #13 (**permalink**) 11-03-2018, 02:14 PM

How you likeing your BDR Bob? I communicated with you previously on FF forum and asked about the stack covers you were using at the time. It was really bad when she burnt up as she was a beauty.

bobcowan · #14 (**permalink**) 11-03-2018, 09:09 PM

The BDR has a very different seating position. The trans tunnel is much wider in the front, and that really moves the gas pedal over to the left. I almost have to work the pedal with the side of my foot.

The car is so fast, I just can't believe it. Your really have pedal the throttle. If you just mash the throttle, it will just boil the tires. Acceleration is brutal. I love it.

I'm still heart broken about my FFR. I loved that car. I owned that car longer than anything I'v ever owned. I put a lot of time and effort in to it. Hundreds of hours of R&D. Sigh.

When the fire was out, the fire chief said, "Your're pretty calm about all this". I said, "I think I'm going to throw up".