Previous Thread
Next Thread
Print Thread
More about manual disc brakes #3003332
01/09/22 12:18 AM
01/09/22 12:18 AM
Joined: Jun 2016
Posts: 721
Washington
H
hemienvy Offline OP
super stock
hemienvy  Offline OP
super stock
H

Joined: Jun 2016
Posts: 721
Washington
Car is 70 E-body.
OK, I have original 10-inch rear drums and I'm adding 73 A-body front discs.
Car has the original manual M/C right now.
I want to keep it as manual brakes, but I could change the M/C if necessary.

Which prop valve setup do I need ?
Which M/C do I need ?

Re: More about manual disc brakes [Re: hemienvy] #3003356
01/09/22 05:04 AM
01/09/22 05:04 AM
Joined: Jan 2007
Posts: 9,427
A Red State
SNK-EYZ Offline
master
SNK-EYZ  Offline
master

Joined: Jan 2007
Posts: 9,427
A Red State
The reservoirs on a disc brake master cylinder are two different sizes, the one for the calipers is larger as it needs more fluid to work properly.

Put a disc brake master cylinder on it, from a 73 A-Body manual disc brake car.
It's what most people run using stock type parts.


Kayse can't keep up at all now. lol
Re: More about manual disc brakes [Re: SNK-EYZ] #3003373
01/09/22 09:16 AM
01/09/22 09:16 AM
Joined: Jun 2008
Posts: 3,669
usa
L
lewtot184 Offline
master
lewtot184  Offline
master
L

Joined: Jun 2008
Posts: 3,669
usa
i did the a-body manual disc conversion on a b-body. i ended up with a 1.03 master cylinder after trying a smaller .93. the car stops but not very well. to do it over again i'd never use a large single piston caliper. beware that some kits use a 2.74 piston for b and e bodies. i had to get rid of the 2.74 and go down to the 2.47 to help in stopping. i have another b-body with 11" drums and power assist and i'd never ever ever ever take those drums off for a disc conversion knowing what i know now. there is absolutely no comparison in stopping.

Re: More about manual disc brakes [Re: lewtot184] #3003379
01/09/22 10:03 AM
01/09/22 10:03 AM
Joined: May 2019
Posts: 3,888
nowhere
S
Sniper Offline
master
Sniper  Offline
master
S

Joined: May 2019
Posts: 3,888
nowhere
Originally Posted by lewtot184
i did the a-body manual disc conversion on a b-body. i ended up with a 1.03 master cylinder after trying a smaller .93. the car stops but not very well. to do it over again i'd never use a large single piston caliper. beware that some kits use a 2.74 piston for b and e bodies. i had to get rid of the 2.74 and go down to the 2.47 to help in stopping. i have another b-body with 11" drums and power assist and i'd never ever ever ever take those drums off for a disc conversion knowing what i know now. there is absolutely no comparison in stopping.


Then you did something wrong.

I've done two a body disc conversions and both work properly. I'd venture to say thousands have been done and work fine. The factory did hundreds of thousands of these and they worked fine.

They key is to mimic the entire factory setup. Not mix and match and delete stuff you don't think you need.

Re: More about manual disc brakes [Re: Sniper] #3003381
01/09/22 10:14 AM
01/09/22 10:14 AM
Joined: Jun 2008
Posts: 3,669
usa
L
lewtot184 Offline
master
lewtot184  Offline
master
L

Joined: Jun 2008
Posts: 3,669
usa
Originally Posted by Sniper
Originally Posted by lewtot184
i did the a-body manual disc conversion on a b-body. i ended up with a 1.03 master cylinder after trying a smaller .93. the car stops but not very well. to do it over again i'd never use a large single piston caliper. beware that some kits use a 2.74 piston for b and e bodies. i had to get rid of the 2.74 and go down to the 2.47 to help in stopping. i have another b-body with 11" drums and power assist and i'd never ever ever ever take those drums off for a disc conversion knowing what i know now. there is absolutely no comparison in stopping.


Then you did something wrong.

I've done two a body disc conversions and both work properly. I'd venture to say thousands have been done and work fine. The factory did hundreds of thousands of these and they worked fine.

They key is to mimic the entire factory setup. Not mix and match and delete stuff you don't think you need.
i doubt it.

Re: More about manual disc brakes [Re: lewtot184] #3003612
01/09/22 09:30 PM
01/09/22 09:30 PM
Joined: Jan 2003
Posts: 8,904
Freeport IL USA
P
poorboy Offline
master
poorboy  Offline
master
P

Joined: Jan 2003
Posts: 8,904
Freeport IL USA
Originally Posted by lewtot184
i did the a-body manual disc conversion on a b-body. i ended up with a 1.03 master cylinder after trying a smaller .93. the car stops but not very well. to do it over again i'd never use a large single piston caliper. beware that some kits use a 2.74 piston for b and e bodies. i had to get rid of the 2.74 and go down to the 2.47 to help in stopping. i have another b-body with 11" drums and power assist and i'd never ever ever ever take those drums off for a disc conversion knowing what i know now. there is absolutely no comparison in stopping.


Did you use a manual brake brake pedal and mount the master with the proper bracket or proper set of mounting holes on the firewall?
A manual brake pedal has a different mounting bracket, and has a different hole for the master cylinder rod to bolt to. That gives the manual brake pedal more leverage then a power brake pedal has. If you used a power brake pedal in a manual brake system, you can't apply as much pressure to the manual brake system that it needs. If you mounted the manual master on the same bracket a power booster mounts to, or in the same set of holes in the firewall the booster mounted to, you have compounded the incorrect pedal problem. There are two sets of holes (or indentions for a set of holes) in the firewall to mount either a bracket the booster, or to bolt the master to, the manual master goes in the upper set of holes on the firewall, and the master cylinder rod bolts to upper hole on the pedal.

I've done probably a dozen of these conversions over the years, never had a problem with the disc brakes being worse then the drums were. Gene

Re: More about manual disc brakes [Re: poorboy] #3003647
01/09/22 10:32 PM
01/09/22 10:32 PM
Joined: Jan 2003
Posts: 12,060
Omaha Ne
T
TJP Offline
I Live Here
TJP  Offline
I Live Here
T

Joined: Jan 2003
Posts: 12,060
Omaha Ne
Originally Posted by poorboy
[
Did you use a manual brake brake pedal and mount the master with the proper bracket or proper set of mounting holes on the firewall?
A manual brake pedal has a different mounting bracket, and has a different hole for the master cylinder rod to bolt to. That gives the manual brake pedal more leverage then a power brake pedal has. If you used a power brake pedal in a manual brake system, you can't apply as much pressure to the manual brake system that it needs. If you mounted the manual master on the same bracket a power booster mounts to, or in the same set of holes in the firewall the booster mounted to, you have compounded the incorrect pedal problem. There are two sets of holes (or indentions for a set of holes) in the firewall to mount either a bracket the booster, or to bolt the master to, the manual master goes in the upper set of holes on the firewall, and the master cylinder rod bolts to upper hole on the pedal.

I've done probably a dozen of these conversions over the years, never had a problem with the disc brakes being worse then the drums were. Gene

up iagree

Re: More about manual disc brakes [Re: hemienvy] #3003675
01/09/22 11:51 PM
01/09/22 11:51 PM
Joined: Jan 2003
Posts: 29,651
Oregon
A
AndyF Offline
Too Many Posts
AndyF  Offline
Too Many Posts
A

Joined: Jan 2003
Posts: 29,651
Oregon
Originally Posted by hemienvy
Car is 70 E-body.
OK, I have original 10-inch rear drums and I'm adding 73 A-body front discs.
Car has the original manual M/C right now.
I want to keep it as manual brakes, but I could change the M/C if necessary.

Which prop valve setup do I need ?
Which M/C do I need ?



Doctor Diff can provide you with what you need. All of my cars have been manual disc brake cars. They work great when you use the correct parts. If you have 15 inch wheels then you should use the 11.75 rotors rather than the smaller A body rotors. Swapping on the larger 11 inch rear brakes will also help. With manual brakes you need all the leverage that you can get.

Re: More about manual disc brakes [Re: AndyF] #3003680
01/10/22 12:24 AM
01/10/22 12:24 AM
Joined: Jan 2003
Posts: 17,868
Eagle, Idaho
Neil Offline
I Live Here
Neil  Offline
I Live Here

Joined: Jan 2003
Posts: 17,868
Eagle, Idaho
I had a 71 Dart Swinger that the previous owner converted to the 73 and up discs. It was a manual brake car and stopped on a dime. No complaints at all for a setup based off factory parts. If you get the right parts it should be all good.

I ended up with a 70 Malibu 350 after that with 4 wheel power drum brakes and missed the brakes on the Dart right away. Had to adjust my driving and give myself more distance to stop as that Chevelle had horrible brakes in comparison.

Re: More about manual disc brakes [Re: Neil] #3003681
01/10/22 12:28 AM
01/10/22 12:28 AM
Joined: Dec 2003
Posts: 6,556
KY
65pacecar Offline
master
65pacecar  Offline
master

Joined: Dec 2003
Posts: 6,556
KY
I am running manual disc brakes on a 65 C Body Sport Fury, work perfectly.

Re: More about manual disc brakes [Re: 65pacecar] #3003732
01/10/22 10:25 AM
01/10/22 10:25 AM
Joined: Jan 2003
Posts: 20,127
Niles , Ohio
T
therocks Offline
Its Lost
therocks  Offline
Its Lost
T

Joined: Jan 2003
Posts: 20,127
Niles , Ohio
Manual discs on my 65 B body for like 20 years now.Run a 70 C body disc master and a IIRC 5th ave PP valve.Stops great even at 120 at the strip.Rocky


Chrysler Firepower






Powered by UBB.threads™ PHP Forum Software 7.7.1