Step # 2 Accumulator Operation Test
STEP # 2: ACCUMULATOR OPERATION TEST: PUMP RUNS MORE THAN 8 SECONDSA. Check for internal leakage in diagnostics procedure. If pump does not self-cycle within five minutes, proceed to Step C.
B. If pump self-cycles (ignition "on", no brakes applied), an internal pressure leak is present.
1. Place a short piece (6-12 inches) of flexible plastic tubing (approximately 1/4 inch-1/2 inch diameter) over Port A in the inboard pump reservoir. See component Identification (Figure 2). If leakage is occurring, fluid will rise in the tube. Repair this fault with Seal Repair Kit 18020067. If no leakage is found, examine Port B.
2. Place the same plastic tubing over Port B. See Component Identification (Figure 2). If leakage is observed here, repair with Check Valve Repair Kit 18018552.
C. De-pressurize the system with ten brake applies and ignition off. Fluid level must be within gauge marks in reservoir.
D. Install J-35126 tool and test to determine if fault is in motor and pump assembly or if fault is in the accumulator. (See NOTE BELOW.)
E. Turn ignition on. Wait until pump motor shuts off. Turn ignition off. Slowly bleed off the accumulator pressure with J-35126 bleed valve - returning fluid to the pump reservoir (inboard side, Figure 2). The gauge pressure will suddenly drop to zero at the accumulator gas pre-charge point.
1. If the drop-off point occurs below 200 psi, replace the accumulator (P/N 18014978 or 18018722).
2. If the drop-off point occurs above 200 psi, replace the pump and motor assembly (P/N 18011279).
Note:
J-35126 per Step 2.D. above is the preferred method. However, if such a tool is not available, the alternative method listed below will provide the necessary diagnostic information to determine the fault.
1. De-pressurize the system per 2.C. Turn ignition on and check the time from motor start running to motor stop running.
2. If time to motor shut-off is less than 15 seconds, replace the accumulator.
3. If the time to motor shut-off is more than 15 seconds, replace motor and pump assembly and then retest accumulator per Accumulator Operation Test (Step # 2 above). If run time on that test is still greater than 8 seconds, also replace the accumulator.