Overview
The Crown Automotive J8126797 is a rear wheel cylinder with a 3/4 inch bore for 9 inch brakes on the 1941–1942 Willys MB and the 1946–1953 Willys CJ-2 and CJ-3. It can be used on either rear side.
The 3/4 inch bore is the key size for matching it to the original.
Key features
- Rear wheel cylinder
- 3/4 inch bore
- For 9 inch brakes
- Driver or passenger side
Rear drum brake care
Rear drum brakes on early Willys models rely on a wheel cylinder to push both shoes against the drum. Because the cylinder works every time the brakes are applied, its cups and bore wear with age. Leaks often start at the boot, so check the area around the cylinder for brake fluid each time you service the rear brakes.
Before fitting a new cylinder, clean the backing plate and confirm the shoes move freely on their pins. Use fresh brake fluid and bleed the lines until no air comes out. Once the new unit is in, road test at low speed and recheck for leaks after the first few drives. Parts of this age often show wear in several places, so inspect the adjusters too.
- Look for fluid near the boot
- Free the shoe pivots and adjusters
- Bleed the rear lines fully
Specifications
| Brand | Crown Automotive |
|---|---|
| Part number | J8126797 |
| UPC | 848399068757 |
| Product type | Drum brake wheel cylinder |
| Position | Rear |
| Bore | 3/4 inch |
| Brake size | 9 inch |
| Side | Driver or passenger |
| Fit type | Direct fit |
Vehicle fitment
It fits the 1941–1942 Willys MB, the 1946–1949 Willys CJ-2 and the 1949–1953 Willys CJ-3. The CJ-5 and CJ-6 are not covered. Confirm fit for your vehicle’s year, model and trim before ordering.
The CJ-5 and CJ-6 are not on the list. Confirm your vehicle’s year, model and trim before ordering.
