borgerding

I'm trying to figure out what the correct Master Cylinder is for my 63 Cutlass.
I have original drums on all wheels and the factory "Kelsey Hayes" bellows type power assist on the inside of firewall.
I posted this in the "brakes" section, but thought I might have better luck here.

I was having general brake issues and decided to go ahead and redo most of the brake system, including ordering a rebuilt MC from Kanter.
(I sent back my orig. MC for core.)

The MC I received from Kanter has a 1" bore, but my Olds service manual indicates the MC for power brakes is a 1 1/8" bore? This is to compensate for the shorter pushrod stroke on the factory power brake setup.

My problem is that Kanter shows (1) MC for both manual and power brakes, and it us the one they sent me, (with the 1" bore). I cannot find any info anywhere on the 1 1/8" MC. Its supposedly discontinued?

I didnt think to measure my orig. MC before sending it back for core, but Kanter claims that it was a 1" bore.

My questions are;

Will this rebuilt MC from Kanter work properly with my power brake setup?

If not, is there another MC available which will?

Is there a MC from a different vehicle which might swap out?

Is there an aftermarket MC/booster setup which will work, (and fit in my small engine compartment?)


Thanks,

1970-W30

You are pretty well stuck with using the 1" bore MC, if you can't buy your core back.
Pedal pressure will be a bit higher with the smaller bore MC, but you don't have much choice at this point. You might not even notice the difference......

borgerding

Thanks,
After an exhausting search for the 1 1/8 bore mc, I've finally surrendured.
Im curious though, when you say pedal pressure will be higher, im assuming you mean that the pedal will be a bit harder. As opposed to meaning a higher "fluid pressure"?
I ask because im still having issues with the rear drums dragging a bit. (They seam to lock up at a dead stop, then it takes a good rev of the engine to free them up. But, they still drag slightly while driving, causing them to heat up.)
Even though its a brand new rebuilt mc from kamter, im going to rebuild it this weekend. All other brake components are brand new.
I know the mc creates residual pressure in the line, but it seems that maybe theres too much pressure in the line?

Thanks

1970-W30

Yes, the pedal will be a bit harder to push because of the smaller bore of the MC, but you might not even notice it because of the booster. I would not recommend rebuilding a new rebuilt unit, you're overthinking it, and it might cause you more problems. Back off on the adjusters on the rear brakes and check the fronts for proper shoe to drum clearance and you should be good to go. If after adjusting front and back shoe to drum clearances, and the brakes still won't unlock by themselves, then the pushrod from brake pedal to the MC has to be shortened a little bit. Do a very small adjustment at a time (1/4 turn) until problem is fixed.