Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Visually inspect the system for any signs of external fluid leaks. Any leaks found? | -- | Go to Step 2 | Go to Step 3 |
2 | Repair any leaks that were found. Is the repair complete? | -- | System OK | -- |
3 |
Does the test lamp light? | -- | Go to Step 4 | Go to Step 7 |
4 | Refer to CAUTION:: This system operates using fluid pressure up to 12 400 kPa (1800 psi). Some malfunctions can cause this pressure to be trapped in the system. Use caution when loosening pipe fittings on a system that does not work or personal injury can result. in Cautions and Notices.
Does any fluid leak out of the fitting? | -- | Go to Step 5 | Go to Step 6 |
5 | Replace the park brake pressure solenoid valve. Refer to Park Brake Solenoid Valve Replacement . Is the repair complete? | -- | System OK | -- |
6 | Replace the park brake pump motor assembly. Refer to Park Brake Pump Replacement . Is the repair complete? | -- | System OK | -- |
7 |
Does the test lamp light? | -- | Go to Step 8 | Go to Step 15 |
8 |
Does the test lamp light? | -- | Go to Step 9 | Go to Step 16 |
9 | Backprobe the park brake relay with a test lamp from terminal 86 to ground. Does the test lamp light? | -- | Go to Step 10 | Go to Step 17 |
10 | Backprobe the park brake relay with a test lamp from terminal 85 to terminal B+. Does the test lamp light? | -- | Go to Step 11 | Go to Step 18 |
11 | Backprobe the park brake relay with a test lamp from terminal 30 to ground. Does the test lamp light? | -- | Go to Step 12 | Go to Step 19 |
12 | Backprobe the park brake relay with a test lamp from terminal 87 to ground. Does the test lamp light? | -- | Go to Step 13 | Go to Step 14 |
13 | Locate and repair the open in CKT 1931 (YEL/BLK), CKT 517 (YEL/BLK) or CKT 534 (YEL/BLK) between the park brake relay and the park brake pressure solenoid valve. Is the repair complete? | -- | System OK | -- |
14 | Replace the park brake relay. Refer to Parking Brake Relay Switch Replacement . Is the repair complete? | -- | System OK | -- |
15 | Locate and repair the open in CKT 1 (ORN), or CKT 536 (ORN), or CKT 150 (ORN) between the I/P fuseblock and the park brake switch. Is the repair complete? | -- | System OK | -- |
16 | Replace the park brake switch. Is the repair complete? | -- | System OK | -- |
17 | Locate and repair the open in CKT 3 (YEL/BLK) or CKT 523 (YEL/BLK) between the park brake relay and the park brake switch. Is the repair complete? | -- | System OK | -- |
18 | Locate and repair the open in CKT 524 (BLK) between the park brake relay and G105. Is the repair complete? | -- | System OK | -- |
19 | Locate and repair the open in CKT 150 (ORN), CKT 516 (ORN) or CKT 533 (ORN) between the park brake relay and the I/P fuseblock. Is the repair complete? | -- | System OK | -- |
