Convertable Front Drums to Disc (Revisited)

Q: Convertable Front Drums to Disc (Revisited)

What do I need to convert my front drums to disc brakes?

A: The 1st Gen Firebirds can use the “early” GM single piston caliper setup. (That is the “corporate” setup – 68-72or74? midsize cars and Nova clones) It came on 1969 Firebirds/Camaros as an option. Don’t spend the $825 for a kit, unless you don’t have any salvage yards around. You should be able to get the wheel assemblies and proportioning valve for $150 – $250. You have to use the Firebird steering arm from the drum brake spindle – transfer it to the disk brake assembly, keeping right and left straight.

You should use the disk brake proportioning valve. It realy is a “combination valve” – the 1968 V8 A/C disk brake Firebirds used a separate proportioning valve, which is different. Another alternative is use the drum brake warning light switch/divider block, and put an aftermarket adjustable proportioning valve in the line to the rear brakes only.

You absolutely have to use a disk brake master cylinder!!!!! It has to be one for power brakes if you have them.

The booster is the same, with the exception of the push rod lengths – you have to see if it pushes on the master cylinder or not – there is an inch or so difference in the masters, I think. The rod to the pedal has to match the car, too. But if you already have power brakes you are all set there.

For my 1968 Firebird, I got new rotors, bearings, hoses, rebuilt calipers, booster, master, plus the junkyard spindles, brackets, splash shields for around $500 total. I painted them with Eastwoods spray paints and they look like $1 million. The car’s not done yet, so no driving report.

Q: Is it absolutely imperative to get the booster and proportioning valve? I got a set of disk brakes from a guy to put on my 1969 several years back and only got the disk brake units.

A: The booster may not be a critical item because you can buy one as a replacement unit from your local parts store. But, the push rod that connects to the brake pedal may be different between drum and disc systems.

The proportioning valve is critical. The disc and drum units are completely different. On some disc systems (like my 69′) there is a separate slave proportioning valve for the front discs. I don’t think you can purchase a replacement from the dealer but you can probably get one from someone like Ames. I’ve also seen them advertised as a separate item from some of these disc brake conversion companies.

Any proposed updates, changes, pictures, and/or corrections, please use our comment section below (may need to click on permalink to access comments feature). Information is subject to change and offered as is without any warranties or guarantees. Please review our Term's Of Use for more information.