Brakes not good enough

[jcd9730]

So my 72's brakes just do not feel 'up to par'. Front disc, rear drum obviously. I installed power brake booster a year ago. Vacuum is subpar (maybe 15" to 17"). I have completely replaced the front pads, calipers, rotors, all lines except the steel ones, complete rear drum rebuild, etc. All flex line replaced. New MC, Booster, PP valve. EVERYTHING new except steel lines. Honestly, I don't understand the why behind replacing steel brake lines unless there is a big problem. But mine bleed fine.

It just doesn't feel right. Big brake kits are a BS waste of money (seriously, look it up, they are not useful at ALL on street cars). Long braking leads to lack of brake power (almost like overheating the drums), hard braking is just not good enough (I can lock it up, but again its at low speeds). When I'm driving, it just feels not good enough.

I know nothing about age of engine, etc. It is not original, but thats all I know. 15 to 17 vacuum is low, but low enough to cause brake problems? I had a 2001 mustang gt, and this truck is just about exactly the same quickness. So the engine is not slugish, but just brake problems.

[jcd9730]

I never had problems with manual brakes, but it is hard to quantify manual brakes. I wonder if it is just the low vacuum, but I have no idea the engine build, camshaft, etc.

[Boog]

What are you comparing the trucks' brake performance to? Your mustang? Or other 67-72 trucks you have owned?

[Swar]

I have stock manual brakes on my '71 c10, front disc, rear drum. The rear locks up all the time. I suggest a rear disc conversion, I plan to do that upgrade soon. No power conversion though, I don't mind having to press harder on the pedal.

[bs46488]

Check out some of the hydroboost conversions.

I'm doing one because of a low vacuum situation.

[Boog]

Ive not used one myself but some guys say the hydroboost is better than the vacumn boost performance wise. Low vacumn is of no concern with that one.

[brown7373]

My 72 with factory power disk/drum stops just fine around town, and a week in the NC mountains last April, up and down the mountains it had no issues. They don't perform like race car brakes, but I don't use it that way. The truck stopped fine all the time.

I don't think 15-17 inches of vacuum is low either. But since you converted from manual disks, I would look there. I don't know, maybe someone else does, but it the rod to the master the same length for manual vs. power disks?

I assume the master was thoroughly bench bled? What kind of pads are you using and are they free from all grease, oil, brake fluid, etc., and not glazed?

Is the same combination or proportioning valve the same for manual and power, and was the button held in when the brakes were bled? If not, there could be more brake action on the rear and not enough on the front disks, which do 80 or 90% of the braking.