Golf GTI L4-1984cc 2.0L DOHC (9A) (1990)
Vacuum Amplifier: Testing and Inspection
Fig. 29 Vacuum Amplifier Test #1
Special tool required:
Slack-tube tester (US 4487 or equivalent)
1.
Zero the slack-tube tester and connect it to the red line between the throttle body and the vacuum amplifier with a 'T' fitting, see Fig. 29.
2.
Start the engine and let it idle.
Reading on the slack tube tester should be 0.3 in. Hg.
Fig. 30 Vacuum Amplifier Test #2
3.
Zero the slack-tube tester and connect it to the blue line between the vacuum amplifier and the thermo-switch, see Fig. 30.
4.
Start the engine and let it idle.
Reading on the slack tube tester should be 1.9 - 3.5 in Hg.
Fig. 31 Vacuum Amplifier Test #3
5.
Connect a hand vacuum pump to the slack-tube tester with a 'T' fitting in the hose, see Fig. 31.
6.
Remove the red vacuum hose from the vacuum amplifier and connect it to the 'T' fitting between the vacuum pump and the slack-tube tester.
7.
Start the engine and let it idle.