Wagoneer L6-242 4.0L VIN L FI (1989)
As brake system pressure increases, pressurized brake fluid is applied to the other side of the diaphragm. As pressure increases, the diaphragm
moves against the pre-charged pressure (fig. 30).
Fig. 31 - Brake System Pressure Approximately 2000 PSI
As brake system pressure increases, the precharged gas pressure is also increased, as the diaphragm compresses the gas pre-charge (fig. 31).