SWITCH STOP LAMP ON MASTER CYLINDER
Brake light switch.
Wartime model with pin connectors
Brake light switch master cylinder
Pressure switch with tapered thread
Brake light switch for mounting on the master cylinder. The switch screws directly into the front of the master cylinder, into the outlet bolt. Essential component for the operation of the brake lights.
|
Mounting Master cylinder (front outlet bolt) |
Type Pressure switch with tapered thread |
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Application Willys MB, Ford GPW, CJ-2A, CJ-3A, CJ-3B, M38 |
OE reference 647801 |
Features
- Screws directly into the front of the master cylinder
- Tapered thread for correct sealing
- Solid pin design with bullet-style terminal
- Pressure-activated switch
- Essential for brake light function
★ High-quality reproduction of the original brake light switch, manufactured to original specifications.
Application
Willys MB (1941-1945), Ford GPW (1941-1945), Hotchkiss M201, Willys CJ-2A (1945-1949), CJ-3A (1949-1953), CJ-3B (1953-1964), M38 (1950-1952). Suitable for vehicles with frame-mounted master cylinder with thread in the outlet bolt.
Installation notes
The switch screws directly into the thread of the outlet bolt at the front of the master cylinder. The tapered thread ensures correct sealing — do not use PTFE tape or jointing compound unless specified by the manufacturer. Check that the original female terminal (bullet-style) is still present in the wiring.
Compatibility
This switch is the solid pin design with bullet-style terminal. Note: some later models (from approximately 1966 onwards) use a nail head (spade) terminal — a different switch is required for these. Not compatible with dual reservoir master cylinders without separate provision for brake light switch.
Historical context
The brake light switch on the master cylinder was standard on all WWII Willys MB and Ford GPW jeeps from 1941, and remained in use on the civilian CJ series and military M38 vehicles into the 1960s.
This description was generated automatically. Unsure about fitment? Contact us at info@willys.be.
⚠ Spotted an error in this description? Report it to info@willys.be
This part is intended for the restoration of historic military vehicles. Fitting, aligning, deburring or reworking is part of that work and is inherent to the nature of these goods. Dimensional variation also exists between original vehicles.
Installation requires technical knowledge of the vehicle. Unsure whether this part suits your version? Ask us before purchase at info@willys.be.
ALL_CATEGORIES : BRAKES MASTER CYL CJ2A, BRAKES MASTER CYL CJ3A, BRAKES MASTER CYL M38, BRAKES MASTER CYL CJ3B
This part fits:
| Model | Years |
|---|---|
| Military jeeps | |
| Willys MB (early) | 1941, 1942 |
| Willys MB | 1942, 1943, 1944, 1945 |
| Ford GPW (early) | 1942 |
| Ford GPW | 1942, 1943, 1944, 1945 |
| Hotchkiss M201 | 1956, 1957, 1958, 1959, 1960, 1961, 1962, 1963, 1964, 1965, 1966 |
| Willys M38 | 1950, 1951, 1952 |
| Willys M38A1 | 1952, 1953, 1954, 1955, 1956, 1957, 1958, 1959, 1960, 1961, 1962, 1963, 1964, 1965, 1966, 1967, 1968, 1969, 1970, 1971 |
| CJ series | |
| Jeep CJ-2A | 1945, 1946, 1947, 1948, 1949 |
| Jeep CJ-3A | 1949, 1950, 1951, 1952, 1953 |
| Jeep CJ-3B | 1953, 1954, 1955, 1956, 1957, 1958, 1959, 1960, 1961, 1962, 1963, 1964, 1965, 1966, 1967, 1968 |
| Jeep CJ-5 | 1955, 1956, 1957, 1958, 1959, 1960, 1961, 1962, 1963, 1964, 1965, 1966, 1967, 1968, 1969, 1970, 1971, 1972, 1973, 1974, 1975, 1976, 1977, 1978, 1979, 1980, 1981, 1982, 1983 |
📐 Diagrams & technical drawings
From the original Technical Manual CJ2A_PL_1949 — Parts List — only for Willys CJ-2A / CJ-3A (1949)
From the original Technical Manual TM 9-1803B — Ordnance Maintenance — Power Train, Body & Frame — only for Willys MB / Ford GPW (¼-ton 4×4)








