Road Testing

Run hose of pressure gauge (83 93 514) from passenger compartment to engine compartment. Position pressure checking gauge vertically. Connect hose of pressure gauge to connection of vacuum hoses placed beside expansion tank. Disconnect APC system by detaching electrical wiring from solenoid valve.
CAUTION: Checking maximum boost pressure in a road test must be performed as quickly as possible (approximately 3-5 seconds) to avoid abnormally high temperatures building up in brake linings.
On cars with manual transmissions, start test by driving car in 3rd gear at an engine speed lower than 1500 RPM. On cars with automatic transmissions, start test by driving car with gear selector in position "1" at an engine speed lower than 1500 RPM.
Depress accelerator pedal to floor. When engine speed approaches 3000 RPM, apply brakes with accelerator pedal pressed to floor. Read boost pressure from gauge with engine held under full load at 3000 RPM.
NOTE: A boost pressure surge may be noted when engine is accelerated to maximum, i.e. boost pressure will momentarily exceed preset maximum figure when accelerator is floored.
Once stabilized, pressure reading should be .03 Bar. Basic pressure setting is only initial setting for function of APC system and has no direct effect on maximum boost pressure level. Engine output is not increased by raising basic boost pressure above .03 Bar.
If basic pressure setting falls outside tolerance, adjust boost pressure regulator basic pressure. If basic pressure setting falls within specified tolerances regulator valve lever stud should be sealed with a tamper-proof seal. Reconnect wiring to solenoid valve. Remove pressure reading equipment.
Car should be driven at least 1/2 of a mile between each test and after testing is completed in order to allow brake linings to cool.