I have spent a lot of my restoration time this year working on cars in my collection that are already restored, but have slight annoyances that have kept me from driving them. My '36 Packard had a leaky,although newly-rebuilt, water pump that dripped just enough so you could smell the antifreeze. The Stingray didnt have brake lights, and my '48 Custom 8 4-door had what seemed to be a sticking left rear brake shoe. The '48 is such a pleasure to drive, and I missed driving it, so I finally decided to pull the rear drum and take a look.
The '40's Packards have tapered rear axles, and require a special, heavy duty, three-armed puller to remove the rear brake drums. Our good buddy Robert Wiley came by to help us with the job, and we pulled the Custom 8 into the shop and up on the lift to check out the problem. After removing the fender skirt, hubcap and cotter pin, I got in to hold down the brake pedal while Robert unscrewed and removed the 1 1/2" axle nut and washer, and set up the arms on the puller to pull the drum. He then disconnected the hand brake, backed the brake shoes off, tightened down the center bolt of the puller, putting pressure on the axle, and the drum popped right off. As we looked at the brakes, it was obvious that the spring on the primary shoe had snapped, preventing the brakes from releasing after being applied. (They weren't just sticking because the car wasnt being driven regularly, as I had thought.) But no problem--we had another spring. We cleaned up everything, put on the new spring, cleaned up the linings and drums with brake cleaner, and put everything back together. While the car was on the lift, we wanted to bleed all of the brakes. Then the bleeder broke off on the brake we had just repaired. Everything had to come back off.
We removed the wheel cylinder and checked its part number and piston bore. It was a 15/16" bore, which is OEM correct for all '48 Packard rears. Before buying a new one, we wanted to be sure we wouldnt have another bleeder valve to break, so we checked the other wheelsbleeders and they turned freely and would bleed okay. We then checked our factory parts manual and found that Packard changed to a larger piston bore on the rear cylinders on its '49 Custom 8 (ours is a '48 Custom 8) to get more fluid to the rear cylinders. We could get original 15/16" bore cylinders or have ours rebuilt, but we decided to do as Packard did in '49, and move up to the 1bore on both rears.
We called NAPA and found them for a little over $10 each, left part # 9025, right part # 9026. The only assembly change was the female to male fitting that goes between the brake line and the wheel cylinder was different. These new NAPA wheel cylinders take a 3/16male to 1/4female part # 7828. It also uses a metric bleeder instead of the 3/8original. That was almost a deal breaker for me. I dont like going back and forth from standard to metric while working on the same car, but since that was the only vice, I moved on, bought everything and put the left side together.
We did the same thing on the right side by removing the fender skirt, hubcap, cotter pin, nut, washer and used the axle puller. This time, the drum would not come off the axle! We unhooked the brake line to release pressure, unhooked the hand brake, backed off the shoes and put pressure on the axle puller, tightening it down while tapping around the circumference of the drum with a hammer. We continued spraying it with penetrating oil, still tapping and tighteningnothing! Two things you dont want to do is heat the axle or hit the center of the axle hard enough to drive it into the thrust plate between the spider gears. If this happens, you can crack the plate, and youll know it immediately upon driving the car by hearing noise from the rear end. Finally, we tightened the puller nut as tight as we could, hit the nut on the puller one moderate hit, and the drum came off! Inside was pretty much the same as on the left side, but with no broken springs, so we cleaned up everything with brake cleaner, took a die grinder with wire wheel and cleaned up the adjuster, and put in the new wheel cylinder. We put just a smear of high heat axle grease on the axle and pushed the drum over the axle and into place, put on the leather* washer, washer, nut, locking it down as tight as it would go with a breaker bar, then the cotter pin. The Packard manual doesnt give a torque spec, but after tightening, it suggests driving it around the block, then re-tightening, then putting in a new cotter pin. We hooked up the hand brake, reconnected the brake line and bled the brakestwice, refilling each time with Dot 3 fluid as recommended (not synthetic).
The brake shoes are adjusted by installing a .10 feeler gauge into a slot in the brake drum and adjusting the shoes until they can be felt up against the feeler gauge with just a little drag. Its the same on all four wheels. Now they stop correctly--no pull, no sticking, and we're ready to enjoy the car without worrying about the brake dragging and overheating.
On behalf of all of us at Southern Wheels Magazine, I would like to thank everyone for letting us share our love for old cars with you, and we wish you and your families a Merry Christmas and a happy 2010!
Keep 'em driving!
*Available from Max Merritt Packard Parts, 800-472-2573, www.packardparts.com
(Thanks to our Packard buddy Ron Carpenter for his consultation on this project, and friendship.)