low performance from brakes

[CJBergquist]

I have a "complete kit" coupe with IRS and I'm not happy with the brakes. My 57 T-Bird with manual brakes stops better than my coupe. It's borderline safe. I have about 1500 miles on the car. The pedal is rock hard...no complaints there. I switched out the supplied pads for Hawk HPS pads...bedded the pads per the instructions...they are better but not much. I've tried adjusting the pedal balance bar but have seen little change. It's almost impossible to get the car to lock up.

Besides spending $3,000 to $4,000 on a complete new set of brakes do you have any suggestions?

[Gordon Levy]

I can help, give me a call when you have a moment.

[Jim Schenck]

Chris,

If you have a 3/4 inch master cylinder for the rear brakes then swap it for a 5/8 inch one. Makes a huge difference in pedal effort. Also I like the more aggerssive track pads from hawk, even on a street car I will run DTC 60s.

[CJBergquist]

Jim, my kit came with two #14772 master cylinders. Not sure which what size(s) they are. Is there a way to visually determine which ones I have? Like a part number.

Gordon, I'll give you a call in the next couple days.

[Jay Kravitz]

Chris,
P/N 14772 is a 3/4" Bore Master Cylinder. We recently changed over to supplying a 5/8" Bore Master Cylinder for the Rear Brakes. If you would like to purchase one give me a call at the Factory 508-291-3443.
Thanks.

[CJBergquist]

Thanks Jay. Yeah I looked at them today and they are both clearly marked 0.75.

[myjones]

Chris,

If you have a 3/4 inch master cylinder for the rear brakes then swap it for a 5/8 inch one. Makes a huge difference in pedal effort. Also I like the more aggerssive track pads from hawk, even on a street car I will run DTC 60s.

Jim
Is this the best combo for the 33 as well
5/8 rear 3/4 front or should I use 5/8 all around?

Thanks
Dale

[Jim Schenck]

Dale,

For the complete kit front brakes and the stock mustang cobra rear brakes the best combo of master cylinders we have found is 3/4 front and 5/8 rear. The cobra (and GT) calipers have a pretty small piston so that is why the 5/8 master works in the rear. If you have different rear brakes with more piston area then the 3/4 rear would still be the way to go.

[CJBergquist]

I swapped out the 3/4" MS for a 5/8" and I have replaced the pads all the way around.

I was able to replace the rear pads without having to disconnect the parking brake. Unfortunately now the rear brakes are dragging.

What's the secret to releasing the automatic tensioner in the ebrake handle?

I'm about ready to cut the cable so I can release the automatic adjuster that is causing my rear brakes to drag.

What year/make/model is the brake cable in a Gen I complete Coupe? The one that goes from the handle to the T bar?

[CJBergquist]

I figured out how to release the tensioner. With the handle in the down position pull back and hold the pawl off the teeth of the tensioner. I used a pair of ViceGrips. Then crawl under the car and pull out the cable. It will go back in but not as far as it was when the pawl was engaged.

https://farm9.staticflickr.com/8605/15412120003_f5e79073cc.jpg

[Jim Schenck]

Chris,

Have you had a chance to drive with the new master in place? The pedal should feel a little softer enough to notice even before you take it for a ride.

[CJBergquist]

Yes I did drive it with the new (5/8) rear master cylinder installed and now that you ask I guess it did feel a little softer and I think there was a noticeable improvement. I was just getting to the point where I was going to start playing with the balance bar. Currently it is smack in the middle. It's been raining here so I have not had a clear, dry day to go bed the pads and see where that takes me. When I get that done I'll let you know how things stand.

Enjoy the holidays and talk to you soon.

[CJBergquist]

Finally got back to the brakes and installed the Hawk HP + pads. Had a couple problems (hand brake tension release and lining up the rear caliper pistons to the pins in the pads) but once that was sorted out I bedded the pads per the instructions and BOY what a difference. I can now check this off my to do list.

[skullandbones]

CJ,
What brakes are you running with your coupe? I'm assuming they are the Wilwood with 4 pot front and single on the rear. It surprises me that you are describing exactly the issue I have with my roadster. I have about 3k on my project and the pedal feel is just as you described (difficult to lock up). My setup is Mustang GT 2000 front and Cobra rear. I have the same Wilwood pedal set with 3/4 inch MC. Thank you, WEK.

[CJBergquist]

WEK...I have the brakes front and rear that FFR supplies in the complete kit and Wilwood foot box.

Front - '99 - '04 Mustang GT - V8
Rear - '03 - 04 Cobra 4.6 V8

At least those are the year/model from the Hawk catalog that got me the pads that fit the FFR supplied brakes.

Did you clean (degrease) your rotors before you installed the pads. I didn't and ended up screwing up the original pads.

[skullandbones]

CJ,

To update: I went over to a friends house (MesaMike). To my surprise he was OK having me do panic stops in front of his house. I was thinking the police would show up at any minute. However, there were some neighbors walking their dogs and other observers. I guess they appreciate hot rods. Also, Mike may have them conditioned to the activities. Anyway, I did several 30 to 40 mph runs and jammed on the brakes. We found that I had my proportioning valve to the rear line cranked down too much. So I eventually backed it off all the way and then turned it back one half turn from full open. We looked at the bias bar. It is fully biased to the front MC. So in the end, we got it to lock the front brakes but the rears were almost but not quite locking (barely turning). That is the closest I could get to where I wanted it. I think the answer is to change the rear MC to the smaller diameter and even out the bias bar a little. That way it will be much more adjustable. However, this was a good compromise. It's not perfect but it will pass for my first track day this Sunday. I noticed a change in the pedal height after the exercise. It was an inch or more lower than before I started. It adjusted back up slightly. I don't think there is any air in the lines but I will double check that tomorrow. To answer your question: I did clean the rotors after having them dressed since they had been sitting up on the wall for a year or two after having them turned. Then I cleaned them with a degreaser and then mineral spirits, I think. I appreciated your thread as it helped me hone in on the issue better. Thanks a lot!

WEK.