The brakes suck!

[69 Rustang]

Am I too used to modern "power brakes"?

I got my '65 convertible running yesterday and bled the brakes today. I pulled the wheels to check out what all had been done and everything is new. It has factory front disks with new calipers, rotors, pads, hardware, and hoses. The master is the large one and it is new. The rears have new drums, shoes, springs, cylinders, etc. The only thing wrong was that the self adjusting cables, arms, and springs are missing. It has the screw adjuster/bolts and some springs holding the shoes together at the bottom. So for now I adjusted the shoes to the drums and bled the brakes. Then took a very slow, careful drive. I did not "seat" the pads yet as I was trying to take it really easy.

IMO, the brakes suck! I have a solid pedal, but I don't think I could lock the wheels if I tried. Any suggestions?

[lunarweasel]

Did you bench bleed the master cylinder?

[Robert65FB]

Does it have power brakes, single or dual res? After I put disc brakes on the front it still braked terribly until I set up metering valve to port more fluid to the front brakes. Your right though it's not a new car and I had to learn it's quirks and not exceed it's limitations, and be thinking about braking earlier than I normally would with newer car.

[69 Rustang]

This is a factory non-power disk brake setup on a '65 Mustang--it was originally equipped this way so not a conversion. The master and all the other brake parts were already installed when I got the car. The master is the large single fruit jar as used on factory disk cars. It is pushing fluid out on all four wheels when bleeding. I remember drum brakes sucking, but didn't expect the disks to be so bad.

[sixteenpushrods]

Just like any new brake job you will have to seat the new pads and shoes. The braking system is very good with the Kelsey Hayes calipers in front and the drums in the rear. Double check the bleeding of the system and make sure you bench bled the master cylinder. It takes a little more effort to stop the car than you might be used to, but if they are weak or feel weak to you, there is probably a problem.

[slim]

Something isn't right! That system with the front discs doesn't suck (if it's right)! Did someone mess with the proportioning valve?

[supershifter2]

many years ago i autocrossed and road raced (on the back roads of south ms.) with only the factory 4 piston disc and master cylinder , i disconnected the line going to the rear barkes and plugged the outlet on the master , used WAGNER WD rivited pads and the stopping power was awesome. i disconnected the rear drums cause they faded realy bad. something aint right with your brakes. could be that racing pads were installed or your not getting enough brake pressure to the front brakes. if the brake lines are the original they could be clogged up , and i have seen that happen before. that car should stop on a dime with those brakes.

[CHOCK]

Supershifter brings up a interesting point.

I tell folks that are experiencing poor braking to block off the rears, totally eliminte them from the equasion, bleed the front disc brakes (Make sure bleeders are pointing up), then test the front brakes for function.

If they brake good, then you know you have a rear braking issue.

Many times poor braking is a rear problem, Poorly adjusted, pressure problem (As stated earlier--Proportioning valve), Rear rubber hoses internally collapsing, etc.

Don't get the Proportioning valve mixed up with the Distribution block. Proportioning valves will go south over time, Impossible for the 65 66 Distribution block to go bad.

When bleeding the rears with someone pushing hard on the brakes, does the fluid Squirt out, or drool out?? Same for front. In other words is there Pressure

The 4 Piston Disc Brakes are Very Good Brakes, Plenty of stopping power, and Fit, Bolt on.

Dan

Classic Mustang Disc Brake Conversions and Power Steering

[22GT]

The 65-66 disc brakes were excellent, I have run mine in autocross competition. If you can't lock all four wheels, something is very wrong.

If the proportioning valve is jammed due to being full of old crud, it can be rebuilt. A jammed valve would result in the same pressure being supplied to all four brakes. Since the discs require far higher pressure than the drums, this would result in being able to lock the rear wheels but not the fronts, resulting in really crappy braking, since the smaller rear drums, not the discs, would be doing all the work.

I like to test the brakes on a gravel road. Really easy tell which ones are working and which are not, just stop using increasing pedal pressure until a wheel locks. This is also the best way to tell if the proportioning valve is working properly. The fronts should lock before the rears. Since the 65-66 factory valve is adjustable, this is something to look for.

[jmagilto]

you have the wrong bore size master cylinder. try a m/c with 1/8 less diameter than you have now. this is a fairly common problem when piecing together brake systems.

I have the Stainless Steel/Kelsey-Hayes disks in manual trim and the brakes are excellent.

call down to mustang ranch in santa clara - they will be able to talk you thru your issue.

hope that helps
jer

ps - i do not recall the appropriate bore size - its been 10+ years since I dealt with it.

[beechkid]

Originally Posted by 69 Rustang

Am I too used to modern "power brakes"?

I got my '65 convertible running yesterday and bled the brakes today. I pulled the wheels to check out what all had been done and everything is new. It has factory front disks with new calipers, rotors, pads, hardware, and hoses. The master is the large one and it is new. The rears have new drums, shoes, springs, cylinders, etc. The only thing wrong was that the self adjusting cables, arms, and springs are missing. It has the screw adjuster/bolts and some springs holding the shoes together at the bottom. So for now I adjusted the shoes to the drums and bled the brakes. Then took a very slow, careful drive. I did not "seat" the pads yet as I was trying to take it really easy.

IMO, the brakes suck! I have a solid pedal, but I don't think I could lock the wheels if I tried. Any suggestions?

Assuming the system is functioning properly, there are issues with the friction materials, specifically, the linings are apec's at a braking co-efficient rating less than the oem spec- not an unusual occuranc today- brake shoes should have a BCE of .37 and disc should be .49 or better.

My thoughts...........

Ceramics: They are good but do not develop any more friction than good quality OEM linings

Performance Friction & Hawk: Good braking, increased friction but very dirty compared to OEM with the exception of VelveTouch- a line that Hawk just bought from Wellman Industries. VelveTouch lining has been used for many decades and was the original lining used in all Shelby Mustangs in the 60’s (I personally have used the Velvetouch lining since 1960’s until brake lining production ceased in 1986). Wellman has been the builder of braking linings for all of the Formula 1 race teams for more than 30 years.

CarboTech Engineering lining, which I have used for about 15+ years and been very happy on multiple full size (V8) cars and trucks. This particular lining has a high friction co-efficient, excellent pedal feel, wear and produces less dust than OEM linings.

Rotors, I have previously run Brembo OEM replacement rotors that are cryogenically treated at Diversified Cryogenics (or ART on the east coast does the cryo tx as well), making them almost as hard as stainless steel. Unfortunately, Brembo, Powerslot, Raybestos, Bendix, Hawk etc. are all purchasing their rotors from the same foundary in China (with the exception of the $300 each composite high end units for Ferrari, Porsche, etc). They purchase the highest grade rotors made, laser mic them for quality, scrap the ones that are out of spec and cryogenically treat the good ones which are now as strong as stainless. They will also slot and cross drill the rotors for you. Their service, price and quality is excellent as well.

For street use, slotted/drilled rotors are just “cheese-graters” for the brake pads IMHO, because unless you are involved in true racing conditions, the brake linings do not produce the gases which slotted/drilled rotors are designed to relive. In some cases, brake testing indicated reduce brake efficiency in street-based operations using slotted/drilled rotors when equal comparisons were made. The staff can speak to you as well regarding those options, but I am very satisfied with the performance & wear of these products.

I also highly recommend using 5.1 DOT (non-silicone) brake fluid. It possesses all the great performance qualities of 5.0 DOT (silicone) but without the negatives. The only issue is for those with custom paint jobs- 5.0 DOT (silicone) fluid will not harm the paint like “conventional” brake fluid will/can.

[supershifter2]

Originally Posted by beechkid

Assuming the system is functioning properly, there are issues with the friction materials, specifically, the linings are apec's at a braking co-efficient rating less than the oem spec- not an unusual occuranc today- brake shoes should have a BCE of .37 and disc should be .49 or better.

My thoughts...........

Ceramics: They are good but do not develop any more friction than good quality OEM linings

Performance Friction & Hawk: Good braking, increased friction but very dirty compared to OEM with the exception of VelveTouch- a line that Hawk just bought from Wellman Industries. VelveTouch lining has been used for many decades and was the original lining used in all Shelby Mustangs in the 60’s (I personally have used the Velvetouch lining since 1960’s until brake lining production ceased in 1986). Wellman has been the builder of braking linings for all of the Formula 1 race teams for more than 30 years.

CarboTech Engineering lining, which I have used for about 15+ years and been very happy on multiple full size (V8) cars and trucks. This particular lining has a high friction co-efficient, excellent pedal feel, wear and produces less dust than OEM linings.

Rotors, I have previously run Brembo OEM replacement rotors that are cryogenically treated at Diversified Cryogenics (or ART on the east coast does the cryo tx as well), making them almost as hard as stainless steel. Unfortunately, Brembo, Powerslot, Raybestos, Bendix, Hawk etc. are all purchasing their rotors from the same foundary in China (with the exception of the $300 each composite high end units for Ferrari, Porsche, etc). They purchase the highest grade rotors made, laser mic them for quality, scrap the ones that are out of spec and cryogenically treat the good ones which are now as strong as stainless. They will also slot and cross drill the rotors for you. Their service, price and quality is excellent as well.

For street use, slotted/drilled rotors are just “cheese-graters” for the brake pads IMHO, because unless you are involved in true racing conditions, the brake linings do not produce the gases which slotted/drilled rotors are designed to relive. In some cases, brake testing indicated reduce brake efficiency in street-based operations using slotted/drilled rotors when equal comparisons were made. The staff can speak to you as well regarding those options, but I am very satisfied with the performance & wear of these products.

I also highly recommend using 5.1 DOT (non-silicone) brake fluid. It possesses all the great performance qualities of 5.0 DOT (silicone) but without the negatives. The only issue is for those with custom paint jobs- 5.0 DOT (silicone) fluid will not harm the paint like “conventional” brake fluid will/can.

i use PORTERFIELD R-4S pads for the street. exelent street pad

[jcthorne]

I looked at a lot of brake pad specs trying to find some front pads with much higher initial coefficient of friction so they would 'feel' much more like power brakes in other cars. I wanted the WAF to be much higher than it was. Finally found EBC Green Stuff pads. MUCH better initial bite and unless you are autocrossing, about all the heat range you could ever want in a pad. They do dust a bit. Not any worse than the semi-metallics that were on the car when I got it but are no where near as clean as a ceramic pad. They drive great, even the wife that hates the car thinks they work just fine....Drove it all the way to Ft Worth a couple months ago.

[69 Rustang]

Update: I took it for another drive this weekend and the brakes performed quite well. I can easily lock them up and the pedal feel has gotten much better. I guess they just needed to seat in a bit.