I’m in the process of replacing the master cylinder on my recently purchased ‘61 Dynamic 88. The master cylinder is seized. Right now I’m leaning towards replacing the single pot with a new single pot, making sure the emergency brake functions and inspect all components...... but while I’m doing a master cylinder replacement I can’t help but think I should just install a dual reservoir master cylinder. So the question, if I went to a dual reservoir, would I be able to use the stock brake booster? Any suggestions on a kit or the master cylinder to buy? With drums all around, I would not need a proportioning valve, just fittings to isolate the front and rear lines? Thanks in advance. Allan
Al, You may get more answers on this over on CO, you know one of the "darksiders" on there has done this..
This is what I did on my 61 Starfire https://classicoldsmobile.com/forum...starfire-dual-master-cylinder-upgrade-139038/ Sent from my iPhone using H.A.M.B.
lol. Thanks!! Just checked it out. That’s exactly what I’m looking for. So a 66 Cadillac booster and master cylinder. Do you happen to remember the thickness of the spacer?
So to bring closure to this, and maybe help someone in the future, the conversion is done. I ended up picking up a booster and master cylinder from a ‘65 Cadillac. Unlike Olds Dad, I didn’t need to build a spacer. The ‘65 booster had 3-1/2” of pedal arm, just as my original booster and the master cylinder was for a drum/drum brake system. The mounting bolt spacing was the same top to bottom but the new booster mounting bolts side to side were 1/2” wider. I hogged out the holes on the firewall plate (not very neatly as I was using a buddies drill press and the bit would wander as I was drilling through the plate as I was only taking away a 1/4” of material on each hole....... but it did work, and once bolted in place you can’t see it anyway. Once bolted to the firewall, the plate acted as a template to clean up the firewall with a dremel. The brake pedal also needed slots cut in the lower mounting holes. I removed the pedal and a Zip disk made short work of the cutting. Cleaned up the booster and master cylinder and mounted them. I reused the brake line splitter block, plugging the port for the rear line and then using a coupler and a 12” line to tie the rear lines to the rear brakes port of the master cylinder. A new 12” brake line tied the front brake block to the master cylinder. The master cylinder has 1/2” ports so I needed to use reducing coupling for the brake lines at the master cylinder which you can see here. All in all a fairly painless conversion and looks much more “original” than an aftermarket dual reservoir and booster conversion. Allan
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