Brakes: 63 Hawk R2, front disc brakes, rear wheel cylinder

[tim333]

Part cross reference for the rear wheel cylinders on disc brake equipped 63 Hawk?

[Randy Bohannon]

p/n 1557668

[tim333]

Randy, I know the OEM number. Thanks. I'm looking for a cross reference number for a FLAPS replacement.

[tim333]

Found it on Northstar' s website: Wagner 41451, but old posts show that number no longer available from Wagner.

[swvalcon]

Rock auto is showing a heavy duty wheel cylinder Dorman #w15306 for $23.89 that shows it fits several Stude's including the 63-64 avanti which all had disk brakes.

[Studebakercenteroforegon]

Rock auto is showing a heavy duty wheel cylinder Dorman #w15306 for $23.89 that shows it fits several Stude's including the 63-64 avanti which all had disk brakes.

So...you believe Rock Auto? 1-3/8" bore? (Correct cylinder has 3/4" bore) The part they list must fit some heavy duty truck but definitely not a car.
I know the correct cylinder from Studebaker part suppliers is expensive, but what is it worth to have correct parts for your brakes?

[StudeRich]

I understand there is a Wheel Cylinder (probably a Truck) available reasonable that FITS the backing Plate.
However since the Bore size is wrong, you'll end up spinning the Car around on medium to hard Braking, or light braking on Water, Snow or Ice, NOT what I would want!

[52 Ragtop]

You need a 3/4" rear wheel cylinder, a lot of the am/kt ones are 7/8". I now have wheel cylinders in stock.

Jim

[52 Ragtop]

You need a 3/4" rear wheel cylinder, a lot of the am/kt ones are 7/8". I now have wheel cylinders in stock. The W15306 shows as a 1 3/8" bore, with a 7/16 x 24 thread, Avanti's (and most Studes) use a 3/8 24 thread. I don't think I'd go there!

Jim

[thunderations]

Are your wheel cylinders pitted where the rubber seal rides? If not, why not hone it lightly and put a kit in it. NAPA has them, #127 for about $6. I had to get one on a Saturday afternoon to repair my 66 Daytona with disc brakes so I could drive it on Sunday to a show. Had no time to order one from any of our fine vendors. Completed the rear brake job the next week, rebuilding the other cylinder and replacing the shoes that I did order.

[swvalcon]

The larger the wheel cylinder size the stronger the rear brakes will be applied. If your worried about rear wheel lock up install a in line adjustable valve and dial it back to what you need.

[52 Ragtop]

Nope, the larger the wheel cylinder, the longer the stroke, and the less pressure, as it takes more fluid to move things out. The smaller wheel cylinder will give a shorter stroke, but more pressure.
Going from a 3/4" wheel cylinder to a 1 3/8" wheel cylinder, you will run out of pedal travel before you are able to stop! You WILL end up with a Honda for a hood ornament!

Jim

[swvalcon]

Jim you would be the guy to know. I read that for every 1/16 in. in piston size you get 9% more stopping pressure. Guess you can't always believe what you read.