Looking to upgrade the factory brakes on my '68 442. Current has factory front discs and rear drums. They don't work great, especially after upgrading my engine which has significantly less vacuum. I also need to run new front brake lines as passenger line currently runs in between two 1 7/8" header tubes (used to run under manifold). I have 15" wheels on so I have room to install slightly larger brakes but in general trying to keep the car relatively stock as it is in such great shape. Looking for suggestions on how to upgrade the brakes to work more effectively without breaking the bank.

 

I wonder is switching to a non-vacuum setup would work better?

 

How much vacuum do you have?

 

10 lbs

 

10 in hg is a bit low but usable. If I were to change, I would go hydroboost.

 

My 70 W30 has factory manual disc brakes and they work really well.

 

I need to ensure my booster and vacuum line is working properly first I suppose. I know 10 in of vacuum isn’t ideal but sounds like it is adequate. I think, based on reading other posts, that they might be underperforming due to my idle mixture being way too rich and idle quality is terrible. Once I let off gas and go to brakes I’m sure vacuum deteriorates rapidly. 10 in of vacuum is what was measured when idle was perfect and perhaps correcting idle quality will make an improvement in braking.

 

Vacuum is highest at idle, with the throttle plates closed. 10 inches Hg is not enough vacuum. It should be in the 17-20 inches range for proper operation of the brake booster. This is why W30 cars with the 328/328 cam came with manual brakes only.

 

This.
I removed my brake booster in my Rallye years ago.
The factory disc/drum set up with good rotors works VERY well manually.
I can hustle my 3800lb car down from 124mph to make the first turn lane at ANY track.
​​​​​​​No drama, no worries.

 

Rallye469 so you just deleted the booster on your power brakes and they work fine? Is that what folks are referring to as "manual" brakes", or is that something different altogether? How difficult is it to delete the booster?

 

Manual brakes are just no power booster - the master cylinder is connected directly to the brake pedal with a pushrod. Two things to keep in mind. First, the brake pedal has two holes, one for the power booster pushrod and one closer to the pivot point for the manual brake pushrod. This changes the pedal ratio, which reduces the required force from your foot in exchange for a little extra pedal travel. Second, the manual brake master cylinder typically has a smaller bore than the one for power brakes (for example, 1" bore for the manual M/C vs 1 1/8" bore for power M/C). Again, this reduces pedal force in exchange for slightly more travel. You need to remove the power booster and M/C and install the M/C for manual brakes.

 

Team Weiland... ^THIS^
It's not very difficult at all.

Joe...that second part about replacing the MC with a smaller bore one...is that necessary?
I honestly can't remember if I did that...but very well might have.
All I can remember is wandering into a junk yard and finding the correct rod for a non power brake car about 30ft from the gate.
Luckiest day of my life I think.

 

I guess it's a function of how much pedal pressure you can tolerate. The factory used a 1" M/C on manual brake cars.

 

Great info, much appreciated. I’ll start by confirming that my booster and hose are working properly and get my idle dialed back in. Likely going EFI anyways, as the elevation changes in Colorado make carburetor tuning a challenge. If braking still not what I want it to bevIll try the manual conversion.