Is the hose connected?
Yes
GO to
A3
.
No
RECONNECT the hose. TEST the system for normal operation.
A3
LEAK CHECK THE VACUUM SUPPLY HOSE
Vacuum Supply Hose
Plug one end of the hose and connect the vacuum pump to the other end. Apply vacuum and observe the gauge
reading.
Does the hose leak?
Yes
REPAIR or REPLACE the vacuum hose. TEST the system for normal operation.
No
GO to
A4
.
A4
CHECK THE VACUUM CHECK VALVE
Check the A/C vacuum check valve (19A563) for correct installation by removing (one at a time) the reservoir
hose and the control assembly source hose from the A/C vacuum check valve. Check for vacuum.
Is vacuum available at both check valve ports?
Yes
GO to
A6
.
No
GO to
A5
.
A5
INSPECT THE VACUUM CHECK VALVE
A/C Vacuum Check Valve
Inspect the A/C vacuum check valve for an obstruction and/or proper operation. Airflow through the A/C vacuum
check valve should be in the direction toward the engine (engine connection site is marked "VAC").
Is the A/C vacuum check valve plugged or obstructed?
Yes
REPLACE the A/C vacuum check valve. TEST the system for normal operation.
No
GO to
A6
.
A6
LEAK TEST THE VACUUM CHECK VALVE
Page 5 of 30
1999 F-150/250 Workshop Manual
8/16/2010
http://www.fordtechservice.dealerconnection.com/pubs/con...
