Mirage L4-1597cc 1.6L DOHC Turbo (1989)
Vacuum Brake Booster Check Valve: Technical Service Bulletins
Brakes - Vacuum Check Valves Identification
SUBJECT:
POWER BRAKE CHECK VALVE TESTING
NO.
TSB-90-35-001
DATE June, 1990
MODEL Galant, Sigma, Mirage
PURPOSE
Two types of power brake vacuum check valves are used on 1989 Galant, Mirage, and Sigma vehicles. The difference between these valves is their
location in the power brake booster system. Both types maintain a limited vacuum reserve in the power brake booster. The early type valve is in the end
of the power brake booster nipple; the later type is located inside the vacuum hose assembly leading from the intake manifold vacuum connector to the
power brake booster. This bulletin provides testing procedures for the later type vacuum check valve located inside the power brake booster vacuum
hose.
WARNING:
When replacing the power brake booster the correct style hose must be installed. If the old style brake booster vacuum hose (without
internal check valve) is installed on the new style power brake booster there will be NO vacuum reserve and this could result in loss of
power brake assist.
CHECK VALVE IDENTIFICATION
LATER TYPE CHECK VALVE TESTING PROCEDURE
1.
Remove the power brake booster vacuum hose from the vehicle.
2.
Using an external vacuum pump, apply vacuum to the booster side of the vacuum hose. If vacuum is held the check valve is good, proceed to step
