Brand new here, just acquired 72 Skylark, has manual 4 wheel drum brakes. Plan is to refurbish the system, master cylinder looks decrepit, so prob buy new. Car sat 2 years, so I guess flush the lines and start over? Should I be looking to convert fronts to disc? Is there recommended kit to use? Would that require different manual master? Or just replace master, drums and shoes? Keeping it original is no preference.... Thanks in advance for advice.
As my memory goes I remember these being a BEAR to stop . I would suggest installing Power Brakes . New Booster , and Master Cylinder . Not that expensive . If you want to go the disc brake way , someone just had a complete setup on the site for sale at a very reasonable price .
I would consider going to power brakes with front disc’s. You maybe able to find a pair of stock disc brake spindles on this forum for cheap then buy stock pads, rotors and calipers. You’ll definitely notice a difference. Also replace rubber hoses and at a minimum rear wheel cylinders. Personally I’d replace all rear brake components if I wasn’t sure of when they were replaced last. Stopping is the most important function in my opinion.
I've got manual disc on my 66 but haven't driven it yet. 7/8 bore master cylinder and correct spot on brake pedal for pivot.
I had 4 wheel manual drums on mine up until 2 years ago......I had no issues stopping at the track till I started going above 125mph........I went to 4 wheel manual dual pistons calipers and she sets right down no issues now...... So drums can be ok for the street.....but most ppl like the feel of disc and power better. I liked the fact that if my.motor konks out for some reason my stop pedal does change the way it feels
I converted the fronts on my 68 skylark. I called The Right Stuff https://www.getdiscbrakes.com/disc-brake-conversions/ They are stocked by summit but the company is local to me here in central Ohio. Call them up and tell them what you want. I ended up with drilled and slotted rotors and powder coated calipers. They have complete kits in different price ranges and included all lines in stainless and brake hoses/lines also. I got stock height spindles could of ordered drop but I didn’t want to worry about ground clearance. Master cylinder they have choices as well. I chose chrome flat top but could have chosen a more stock appearance. Was free shipping when I ordered they shipped in 3 boxes for weight
My '68 with manual drums stopped fine, without excessive effort, but I never went near 125 ;~) Drums tend to steer the car bit when the brake is applied, and they do fade due to heat build up on prolonged heavy braking. I converted mine to power discs using a parted out 442 (Master, booster, valve, hubs, spindles calipers). It's an excellent upgrade.
My chevelle had 4 wheel manual drums on it. It didn't bother me but it scared the crap out of my wife. Most people don't expect a brake pedal to feel like a brick.
Power brakes are far superior to manual, BUT how your going to use the car can help you decide what to do. If you are going to leave it as is and want to save some money, leave the manual drums alone. If your going to start modifying it to make more power then an upgrade to power brakes and front rotors is a no brainer.
Just finished all new wheel cylinders, new master, bleeding wasca bear, rear brakes did not want to bleed....after repeated tries, and forceful leg power, finally blew through some nasty oil/sediment. Flush out completely, bled all wheels 3 times, now have great manual brakes! Thanks for all the help.
I've been beating this manual brakes stuff to death... The 1st gen 64-67 a-body Has a lot less room than a 2nd gen... Big Motor Big Valve Covers,, no room booster is in the valve cover... Right now Im using a https://www.napaonline.com/en/p/NMAM1922. Its a 1'' bore. It will stop you if your just cruising... Panic stop NOT happening...End of life... What is needed is a 7/8'' bore to to stop properly.... NOBODY Including the the company in post 7 makes a 7/8 manual master brake cylinder... There are 2 7/8'' bore MC..... One is a Wilwood its a dual, power or manual..... Then there is a Raybestos MC39027 fits a chevy Monza car.. But its a power brake unit.... to make it work you need this goofy gismo https://www.inlinetube.com/products/inl12439 and or this also..https://www.ebay.com/itm/64-72-Manu...edal-Foot-Push-Rod-Assembly-GTO-/200879400866 The gismos dont in any way shape or form make me feel safe. Infact I feel safer with my 1'' bore MMC... Now just what are you guys with the Factory Manual brake 455 st1 GSX car numbers correct using for a MMC?????????????????????
I took a few pictures of my setup which includes metal retainer. without that there's nothing to keep the rod from slipping out of the end of the master cylinder. Apparently they don't make the deep Master cylinders anymore. it looks like my master cylinder is a 1 inch bore so I am going to order the Monza master cylinder and take a look at it and see if it will work. There's quite a pressure difference between a 1 inch and a 7/8 bore master cylinder. Here is some info on master cylinder with "constant" of 6 to 1 pedal ratio and 100 psi being applied. 3/4" master cylinder = 1359 psi 13/16" master cylinder = 1158 psi 7/8" master cylinder = 998 psi 15/16" master cylinder = 870 psi 1" master cylinder = 764 psi 1-1/8" master cylinder = 603 psi
I'm going with one.....https://www.wilwood.com/MasterCylinders/MasterCylinderProd?itemno=260-9439-BK. I just dont trust that adapter... I'll never forget the day the pin that holds the rod to the peddle fell out..... Thank God it was a stick trans and flat ground and no one was going through the intersection... Either the one above or a Hydro-boost system.
That is the manual master cylinder I'm going to use for my '70. In fact, I just ordered it today. "Big" cam (Kenne Bell Window Rattler) is the plan, so I know I won't have much for vacuum. I'm planning on keeping the front discs, and using rear drums, with the factory distribution block, front cast iron hold-off valve, and a 10 lb. residual pressure valve plumbed into the rear line for the drums. I'm hoping that'll be enough to stop it, because I really don't have many other options to look somewhat correct. Bonus is the master looks factory correct, minus the giant booster behind it. Pretty sure my original power brake master I lost had dual bleeders on it.
Mopar has smaller bore master cylinders. Plastic/aluminum. Aerospace components sells them. 1000 psi rating.
