Discussion:
B Body Disc Brake Upgrade
(too old to reply)
Blaster!
2003-07-26 08:39:04 UTC
Permalink
So I am thinking it is time to ditch the drums on my 67 Coronet. I can use
OEM parts, Stainless Steel, Wildwood...what do I gain by sticking with Mopar
factory stuff besides more money in the bank? The SSBrakes seem good with a
four piston design but will I run into problems getting replacement parts if
needed? Will Wildwoods stand up to a daily driver?

Is there another option I should be looking at? Is it worth the trouble and
money to upgrade the rear 8 3/4 to disc?

And lastly...power or no power? It is a daily driver w/318 and maybe...just
maybe...get a crate 360 for it but no big block.

Thanks for the advice!
Raffi3834
2003-07-27 02:32:21 UTC
Permalink
I just got the "Master Power Brake conversion" working on my '68 Charger.

DON'T BUY THEIR KIT.

Their booster is too small and the GM master cylinder they sell you has too big
a bore diameter. Car would barely stop.

Do the "A" body conversion.

More details after I get my refund for all of the parts I sent back.

Raffi
Post by Blaster!
So I am thinking it is time to ditch the drums on my 67 Coronet. I can use
OEM parts, Stainless Steel, Wildwood...what do I gain by sticking with Mopar
factory stuff besides more money in the bank? The SSBrakes seem good with a
four piston design but will I run into problems getting replacement parts if
needed? Will Wildwoods stand up to a daily driver?
Is there another option I should be looking at? Is it worth the trouble and
money to upgrade the rear 8 3/4 to disc?
And lastly...power or no power? It is a daily driver w/318 and maybe...just
maybe...get a crate 360 for it but no big block.
Thanks for the advice!
Raffi
(Scrap the ford to reply. I'm tired of the junk mail.)
RedNeck TookOver Hell
2003-07-28 16:51:21 UTC
Permalink
Amazing!!!!!!
Now that the spindles are available new, I can't imagine why anyone would do
any conversion other than the MoparAction conversion except with Wil Woods in a
race car.
Upgrade to the Mopar aluminum master cylinder, used by about 95% of race cars,
and get the "big" 11.87? rotors, throw the booster over the nearest fence and
don't even worry about it.
Richard Ehrenberg from MoparAction will tell you that the pedal ratio on a non
power Mopar is superior to a power one
The factory stuff just bolts together and doesn't require any cobbling to make
it work There are "new age" pads available and even an adapter to put WilWood
calipers on the stock rotors & spindles
Remember the K I S S principle, Keep It Simple Stupid
Post by Raffi3834
I just got the "Master Power Brake conversion" working on my '68 Charger.
DON'T BUY THEIR KIT.
Raffi3834
2003-08-13 23:39:45 UTC
Permalink
The long awaited LONG answer:

The LONG Tale of the Master Power Brake Disc Brake Conversion ('68 Charger)

Summary: I would never buy anything from Master Power Brakes again. "You" can
do what "you" want to.

Long Version:

Back in May or June, it seems so long ago and I don't remember, I ordered a
power disc brake conversion kit for my '68 Charger. It arrived about a week or
so later. While I was waiting, I took apart the whole front end, put in new
torsion bars, and a PST front end Super Kit. I wouldn't buy their parts again
either but that is a whole different story.

The brake parts arrived and I started installing them. The caliper brackets
bolted right on. The left side rotor went right on. The right side didn't.
The caliper bracket had an extra large bump in the casting that hit the rotor.
Out came the file. Next step was to install the calipers. Left side went
right on. Right side didn't. Pad was hitting the caliper bracket. More
filing on the pad this time.

Next step of the "Bolt-on" process was installing the hydraulic lines. They
would have fit fine had the vehicle not had upper control arms or a "frame".
However, since a Charger has both (kind of, I know it's a unibody), the lines
don't fit. This led to the first call to MP Brakes where I was told that they
haven't had that problem before. They recommended bending the steel line at
the banjo fitting. To me, bending doesn't fall under the definition of
"bolt-on". So, I bent the lines to allow them to clear the calipers and the
control arms. Now, however, they need to enter the frame mounted brake line
from the top side instead of the bottom side like the original hoses did.
There goes the year old brake lines. All new lines needed to be bent for the
front brakes.

So, we finally get everything put together and bleed the brakes. Just to let
you know, the rear brakes had been done in the spring. All new springs, wheel
cylinders, shoes, and nicely turned drums. The only old part left in the brake
system was the brake pedal.

As we pulled out of the garage and slowly drove up the street, we prepared for
the first brake test. Fred Flinstone's car stops faster. Slowly drove around
the subdivision stopping all over. Tried to do some hard stops and basically
the car would coast to a stop.

Called MP Brakes and they recommended bleeding the brakes. We did it again
knowing that there was nothing wrong with how they were bled the first time.
No difference in braking.

Called MP Brakes again. They agreed to send me their pressure gage as a loaner
after I explained that if I bought something for $800 at the local store and it
didn't work that I would take it back. Did a pressure test and had 800 psi at
the front brakes and 650psi at the rear brakes. This is at or above their
recommended level.

Called MP Brakes again. They told me to go buy a new set of pads to try and
that they would pay for them. Installed the new pads and there was no
difference in braking.

Called MP Brakes again. This time they decided to send me a new booster. I
didn't think there was anything wrong with their original booster based on
disconnecting the vacuum line one time to see how the car would stop. There
was a noticeable difference with and without vacuum. The new booster came.
Anyone who has changed a power booster on a '68 B-body knows how much fun it
is. Put the new booster on and no difference.

I had also talked to one of the brake engineers at work. He was thinking that
a master cylinder with a smaller piston diameter would help. The MP Brakes kit
comes with a GM master cylinder that has a 1 1/8" diameter. The Chrysler
master cylinder has a 1" diameter piston.

After the new booster didn't work, we installed the original booster and master
cylinder that were on the car before this "bolt-on" project started. Amazingly
enough I had brakes. I could finally lock up the front wheels on pavement.
The rears won't lock up. The fronts wouldn't even lock up on dirt with the MP
Brakes booster and master cylinder.

Called MP Brakes again. Told them that I wanted the Chrysler disc/drum master
cylinder that they have listed on their web site. I also wanted it shipped
overnight which they agreed to once I agreed to pay half of the shipping.

I talked to the brake engineer at work again. He said he had spent some time
going through the MP Brakes web site and had come to the conclusion that the
master cylinder and the brake booster from the kit were both inadequate for the
application.

He gave me a brake pedal force vs deceleration tester to try out. The car will
stop at about 0.8-0.82g's with 50-90lbs of pedal force. The front wheels start
to lock-up at this braking level. The brake engineer felt that 0.8 g's was a
good level for the car considering it doesn't have ABS. Based on the data with
lower pedal forces, he also asked if the brakes seem to come on rather quickly
which they do. At least the car stops and I'm not afraid to drive it.

My recommendation to anyone who wants to do the conversion is to NOT buy the
kit from MP Brakes. I know some of you have bought it and have not had any
troubles. Why I had these problems, I don't know but I wouldn't want anyone
else to go through it. MP Brakes did refund me the cost of the pads and the
booster that I didn't need minus the cost of the overnight shipping after I
sent them the two boosters and the master cylinder (they paid shipping). I
even got to keep the pressure gage which is of dubious quality based on how
badly the housing is cracking and falling apart.

Some parts you need to do it yourself:
Pads are part number D84. They fit Aspens/Volares. Calipers and rotors also
fit Aspen/Volare. Master cylinder is a Bendix 11571 (4 bolt)which can be
ordered from any part store that sells Bendix parts. Use the 9" booster (4
bolt) that you already have. You'll need a combination valve. If you want new
spindles and caliper brackets, you may have to buy them from MP Brakes. I
would try to find them somewhere else first.

I don't know if MP Brakes did any engineering to try to figure out this kit.
My guess is they didn't. I sure got to do a lot of extra work.

Glad it's fixed in time to cruise Woodward.

Raffi
Post by Raffi3834
I just got the "Master Power Brake conversion" working on my '68 Charger.
DON'T BUY THEIR KIT.
Their booster is too small and the GM master cylinder they sell you has too big
a bore diameter. Car would barely stop.
Do the "A" body conversion.
More details after I get my refund for all of the parts I sent back.
Raffi
Post by Blaster!
So I am thinking it is time to ditch the drums on my 67 Coronet. I can use
OEM parts, Stainless Steel, Wildwood...what do I gain by sticking with Mopar
factory stuff besides more money in the bank? The SSBrakes seem good with a
four piston design but will I run into problems getting replacement parts if
needed? Will Wildwoods stand up to a daily driver?
And lastly...power or no power? It is a daily driver w/318 and maybe...just
maybe...get a crate 360 for it but no big block.
Thanks for the advice!
Raffi
(Scrap the ford to reply. I'm tired of the junk mail.)
Joshua Skinner
2003-08-14 01:12:57 UTC
Permalink
Damn, I do better by rolling my own kit from used and new parts from/for A bodies.
Just did my '64 Valiant recently. If I remember correctly you bought the Master
Power kit to save time. Sorry to hear it did anything but. If you ever need more
front brake you can use FMJ calipers as they have larger pistons than '73-'75 a
body calipers. '76 A body calipers are the same as the F body calipers. If you ever
fade the brakes try Raybestos Super Stop pads (SSD84). Those things are awesome. I
use them on my road race '66 Dart. They work cold and hot and last a long time.
Easy on the rotors too. I think they must be ceramic.

Joshua Skinner
Post by Raffi3834
The LONG Tale of the Master Power Brake Disc Brake Conversion ('68 Charger)
Summary: I would never buy anything from Master Power Brakes again. "You" can
do what "you" want to.
Back in May or June, it seems so long ago and I don't remember, I ordered a
power disc brake conversion kit for my '68 Charger. It arrived about a week or
so later. While I was waiting, I took apart the whole front end, put in new
torsion bars, and a PST front end Super Kit. I wouldn't buy their parts again
either but that is a whole different story.
The brake parts arrived and I started installing them. The caliper brackets
bolted right on. The left side rotor went right on. The right side didn't.
The caliper bracket had an extra large bump in the casting that hit the rotor.
Out came the file. Next step was to install the calipers. Left side went
right on. Right side didn't. Pad was hitting the caliper bracket. More
filing on the pad this time.
Next step of the "Bolt-on" process was installing the hydraulic lines. They
would have fit fine had the vehicle not had upper control arms or a "frame".
However, since a Charger has both (kind of, I know it's a unibody), the lines
don't fit. This led to the first call to MP Brakes where I was told that they
haven't had that problem before. They recommended bending the steel line at
the banjo fitting. To me, bending doesn't fall under the definition of
"bolt-on". So, I bent the lines to allow them to clear the calipers and the
control arms. Now, however, they need to enter the frame mounted brake line
from the top side instead of the bottom side like the original hoses did.
There goes the year old brake lines. All new lines needed to be bent for the
front brakes.
So, we finally get everything put together and bleed the brakes. Just to let
you know, the rear brakes had been done in the spring. All new springs, wheel
cylinders, shoes, and nicely turned drums. The only old part left in the brake
system was the brake pedal.
As we pulled out of the garage and slowly drove up the street, we prepared for
the first brake test. Fred Flinstone's car stops faster. Slowly drove around
the subdivision stopping all over. Tried to do some hard stops and basically
the car would coast to a stop.
Called MP Brakes and they recommended bleeding the brakes. We did it again
knowing that there was nothing wrong with how they were bled the first time.
No difference in braking.
Called MP Brakes again. They agreed to send me their pressure gage as a loaner
after I explained that if I bought something for $800 at the local store and it
didn't work that I would take it back. Did a pressure test and had 800 psi at
the front brakes and 650psi at the rear brakes. This is at or above their
recommended level.
Called MP Brakes again. They told me to go buy a new set of pads to try and
that they would pay for them. Installed the new pads and there was no
difference in braking.
Called MP Brakes again. This time they decided to send me a new booster. I
didn't think there was anything wrong with their original booster based on
disconnecting the vacuum line one time to see how the car would stop. There
was a noticeable difference with and without vacuum. The new booster came.
Anyone who has changed a power booster on a '68 B-body knows how much fun it
is. Put the new booster on and no difference.
I had also talked to one of the brake engineers at work. He was thinking that
a master cylinder with a smaller piston diameter would help. The MP Brakes kit
comes with a GM master cylinder that has a 1 1/8" diameter. The Chrysler
master cylinder has a 1" diameter piston.
After the new booster didn't work, we installed the original booster and master
cylinder that were on the car before this "bolt-on" project started. Amazingly
enough I had brakes. I could finally lock up the front wheels on pavement.
The rears won't lock up. The fronts wouldn't even lock up on dirt with the MP
Brakes booster and master cylinder.
Called MP Brakes again. Told them that I wanted the Chrysler disc/drum master
cylinder that they have listed on their web site. I also wanted it shipped
overnight which they agreed to once I agreed to pay half of the shipping.
I talked to the brake engineer at work again. He said he had spent some time
going through the MP Brakes web site and had come to the conclusion that the
master cylinder and the brake booster from the kit were both inadequate for the
application.
He gave me a brake pedal force vs deceleration tester to try out. The car will
stop at about 0.8-0.82g's with 50-90lbs of pedal force. The front wheels start
to lock-up at this braking level. The brake engineer felt that 0.8 g's was a
good level for the car considering it doesn't have ABS. Based on the data with
lower pedal forces, he also asked if the brakes seem to come on rather quickly
which they do. At least the car stops and I'm not afraid to drive it.
My recommendation to anyone who wants to do the conversion is to NOT buy the
kit from MP Brakes. I know some of you have bought it and have not had any
troubles. Why I had these problems, I don't know but I wouldn't want anyone
else to go through it. MP Brakes did refund me the cost of the pads and the
booster that I didn't need minus the cost of the overnight shipping after I
sent them the two boosters and the master cylinder (they paid shipping). I
even got to keep the pressure gage which is of dubious quality based on how
badly the housing is cracking and falling apart.
Pads are part number D84. They fit Aspens/Volares. Calipers and rotors also
fit Aspen/Volare. Master cylinder is a Bendix 11571 (4 bolt)which can be
ordered from any part store that sells Bendix parts. Use the 9" booster (4
bolt) that you already have. You'll need a combination valve. If you want new
spindles and caliper brackets, you may have to buy them from MP Brakes. I
would try to find them somewhere else first.
I don't know if MP Brakes did any engineering to try to figure out this kit.
My guess is they didn't. I sure got to do a lot of extra work.
Glad it's fixed in time to cruise Woodward.
Raffi
Post by Raffi3834
I just got the "Master Power Brake conversion" working on my '68 Charger.
DON'T BUY THEIR KIT.
Their booster is too small and the GM master cylinder they sell you has too big
a bore diameter. Car would barely stop.
Do the "A" body conversion.
More details after I get my refund for all of the parts I sent back.
Raffi
Post by Blaster!
So I am thinking it is time to ditch the drums on my 67 Coronet. I can use
OEM parts, Stainless Steel, Wildwood...what do I gain by sticking with Mopar
factory stuff besides more money in the bank? The SSBrakes seem good with a
four piston design but will I run into problems getting replacement parts if
needed? Will Wildwoods stand up to a daily driver?
And lastly...power or no power? It is a daily driver w/318 and maybe...just
maybe...get a crate 360 for it but no big block.
Thanks for the advice!
Raffi
(Scrap the ford to reply. I'm tired of the junk mail.)
Raffi3834
2003-08-15 00:42:55 UTC
Permalink
Joshua,

As you correctly remembered, the main reason for going with the kit was the
expected time savings. That worked out great.

Those Raybestos SSD84's sound nice. It took about 3 medium stops and 3 hard
stops before I started smelling the brakes during my testing.

I was actually looking up local autocrosses. I used to autocross my '73
Charger. Need to install the rear sway bar first. That will happen after the
shed construction project ends.

Raffi
Post by Joshua Skinner
Damn, I do better by rolling my own kit from used and new parts from/for A bodies.
Just did my '64 Valiant recently. If I remember correctly you bought the Master
Power kit to save time. Sorry to hear it did anything but. If you ever need more
front brake you can use FMJ calipers as they have larger pistons than '73-'75 a
body calipers. '76 A body calipers are the same as the F body calipers. If you ever
fade the brakes try Raybestos Super Stop pads (SSD84). Those things are awesome. I
use them on my road race '66 Dart. They work cold and hot and last a long time.
Easy on the rotors too. I think they must be ceramic.
Joshua Skinner
Raffi
(Scrap the ford to reply. I'm tired of the junk mail.)
Joshua Skinner
2003-08-15 01:40:29 UTC
Permalink
Autocross is usually pretty easy on the brakes. Road racing brakes stuff that
you'd never break on the street. My Dart only does 14.60s in the 1/4 mile, but I
can race it pedal down for 1/2 hour at a time no problem. Many drag cars are hot
after a couple passes. Not to say my car doesn't get hot, but it sure doesn't
overheat.

See if you still smell the brakes after a week or so. Sometimes the pads need to
break in and will out-gas during the process. It used to be with racing pads you'd
run them and use the brakes progressively harder until they just faded and then
let them rest for 24 hours. It was like breaking in racing tires. You couldn't put
brand new pads on the car on race day and get optimum performance.

The rear sway bar will help a lot in an autocross just as long as it doesn't lift
a rear tire and create wheelspin. A good Sure-Grip is a must as are the largest,
stickiest tires you can fit under the car without rubbing. It's a shame I can only
get a 225/50R15 under my '66. It's also a shame it has manual steering. It's 16:1
fast manual steering, but the effort is high enough that it's impossible to keep
up with steering inputs and it really slows your down.

Joshua
Post by Raffi3834
Joshua,
As you correctly remembered, the main reason for going with the kit was the
expected time savings. That worked out great.
Those Raybestos SSD84's sound nice. It took about 3 medium stops and 3 hard
stops before I started smelling the brakes during my testing.
I was actually looking up local autocrosses. I used to autocross my '73
Charger. Need to install the rear sway bar first. That will happen after the
shed construction project ends.
Raffi
Post by Joshua Skinner
Damn, I do better by rolling my own kit from used and new parts from/for A bodies.
Just did my '64 Valiant recently. If I remember correctly you bought the Master
Power kit to save time. Sorry to hear it did anything but. If you ever need more
front brake you can use FMJ calipers as they have larger pistons than '73-'75 a
body calipers. '76 A body calipers are the same as the F body calipers. If you ever
fade the brakes try Raybestos Super Stop pads (SSD84). Those things are awesome. I
use them on my road race '66 Dart. They work cold and hot and last a long time.
Easy on the rotors too. I think they must be ceramic.
Joshua Skinner
Raffi
(Scrap the ford to reply. I'm tired of the junk mail.)
Raffi3834
2003-08-17 23:36:45 UTC
Permalink
I have Radial T/A 245/60R15's on the fronts and 275/60R15's on the rears. Not
too concerned about perfecting the setup for autocrossing since the first thing
would be to get a smaller car. Just like to go out and have fun once in a
while.

I used to use $5 ea. junkyard specials on the '73 when I was racing in college.
Finally bought a set of Eagle GT 245/60R15's. Never had trouble with the
tires actually lifting off the ground like you would see with Omnis and
Rabbits. Had '74 or so mid size Fury police car sway bars on it.

Raffi
Post by Joshua Skinner
Autocross is usually pretty easy on the brakes. Road racing brakes stuff that
you'd never break on the street. My Dart only does 14.60s in the 1/4 mile, but I
can race it pedal down for 1/2 hour at a time no problem. Many drag cars are hot
after a couple passes. Not to say my car doesn't get hot, but it sure doesn't
overheat.
See if you still smell the brakes after a week or so. Sometimes the pads need to
break in and will out-gas during the process. It used to be with racing pads you'd
run them and use the brakes progressively harder until they just faded and then
let them rest for 24 hours. It was like breaking in racing tires. You couldn't put
brand new pads on the car on race day and get optimum performance.
The rear sway bar will help a lot in an autocross just as long as it doesn't lift
a rear tire and create wheelspin. A good Sure-Grip is a must as are the largest,
stickiest tires you can fit under the car without rubbing. It's a shame I can only
get a 225/50R15 under my '66. It's also a shame it has manual steering. It's 16:1
fast manual steering, but the effort is high enough that it's impossible to keep
up with steering inputs and it really slows your down.
Joshua
Raffi
(Scrap the ford to reply. I'm tired of the junk mail.)

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