Pull-Down RPM Check
Note: This test is accurate only if the engine provides the rated horsepower.
- Run the engine to high idle (Top Engine Limit) (TEL) and fully apply BrakeSaver.
- Reduce the throttle position until the engine stabilizes at 1800 rpm.
- Record the fuel rate from the ECAP.
- There are two methods for checking the BrakeSaver. The first method requires a fuel rate specification to be produced. The fuel rate specification should have a tolerance that will work for all engines from 410 HP to 600 HP. The second method requires the power that is absorbed by the BrakeSaver to be calculated. Calculate the power by using the fuel rate and the history from the engine test cell. The power that is calculated is called the Brake Specific Fuel Consumption (BSFC). Compare this number to the BrakeSaver that is performed at 1800 rpm.
NOTICE |
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Do not run the engine at high idle rpm with the BrakeSaver ON for more than 15 seconds at a time. Let the engine run at low idle with the BrakeSaver off for five minutes to keep from getting the engine cooling system too hot. |
Klunk Check (Check For Free Movement Of The Valve Spool)
- Run the engine until the maximum vehicle air system operating pressure is obtained. Stop the engine.
Illustration 1 | g00303164 |
Gauge Holes For Troubleshooting (1) Oil pressure from the BrakeSaver. (2) Oil pressure from the engine. (3) Oil pressure to the BrakeSaver. (4) Test point for BrakeSaver oil temperature. (5) Oil pressure to the engine. (6) Air pressure line from the control valve. (7) Oil pressure to the cooler. (8) Oil pressure from the cooler. |
- Put the BrakeSaver in the full ON position before the air pressure in the truck air system gets below 480 kPa (70 psi).
- Put the BrakeSaver in the OFF position. A noise (KLUNK) must be heard at the BrakeSaver control valve as the valve spool hits the cover at the air inlet end of the control valve.
- If a noise is not heard at the BrakeSaver control valve, remove the control valve and disassemble the control valve. Inspect the valve for the following areas.
- A damaged valve body
- Damaged springs or worn springs in the valve spool
- A damaged valve spool or worn valve spool
- Damaged O-ring seals, worn O-ring seals or diaphragm in the control valve
- Closed holes in the side of the valve spool
For specific problems, make reference to the BrakeSaver Troubleshooting Problem List.
- A damaged valve body
BrakeSaver Troubleshooting Problem List
- BrakeSaver Does Not Give Full Braking Force With The Mode Selector Switch In The "MANUAL" Position.
- BrakeSaver Does Not Give Full Braking Force With The Mode Selector Switch In The "AUTOMATIC-MANUAL" Position.
- BrakeSaver Oil Temperature Is Too High.
- BrakeSaver Does Not Turn "OFF" Or BrakeSaver Does Not Become Empty.
- Oil Leakage From The Flywheel Housing.
- Oil Leakage From The Clutch Housing Or The Transmission.
Illustration 2 | g00303178 |
Illustration 3 | g00303183 |
Illustration 4 | g00303184 |
Illustration 5 | g00303185 |
Illustration 6 | g00303203 |
Illustration 7 | g00303204 |