Possible Helpful Hints and brake test

Thanks to www.reatta.net for the information

If the "System" fails, (RED light is on) you still should have some, very, very limited stopping power, which might be helped by pumping the Emergency pedal until hard and continue to press the brake pedal as hard as you can! You can try this in your driveway, if it slopes, by putting car in neutral, turn key to off, pumping pedal until it gets hard as a rock, coast down the driveway and attempt to stop (Be careful!).

If your yellow light is on (again, be careful) you can test to see if the Anti-lock system is actually working by simulating an EMERGENCY stop at a speed of 30 mph. If a wheel tries to lock up or slide you will feel a chatter in the pedal and it may even rise a little. If you feel no chatter your Anti-lock is either not working or you haven't applied brakes hard enough.

A "safer" check, as the yellow light cause may be a failed Main Relay, would be to switch the Main and Pump Relays and see if the light goes out. (in some cases, if the Main Relay has failed, after switching, both lights may be on.) See note re. intermittent relay failure!

If you apply your brakes and the red light comes on but goes out in a short time, your PUMP has re-pressurized the system but you may have a weak or failed Accumulator or other problems!

CRT DISPLAYS and CODES SET by the ECBM

The CRT (88 and 89 models) will display three messages pertaining to the brake system.

1. Brake fluid low
2. Parking brake is on
3. Anti lock Brakes (initiated by low brake pressure)

Note: BRAKE TROUBLE CODES do not appear on the CRT nor are they displayed when DIAGNOSTICS is selected and BCM selected. BRAKE TROUBLE CODES are stored in the ALDL. (Assembly Line Diagnostic Link) Codes (42 can be stored) are set by the ECBM and retrieved by grounding or jumping pins in the ALDL Connector. The codes stored refer to wheel sensors, the main valve or the inlet and outlet valves. No codes are stored by conditions affecting the pump/motor, the accumulator, the pressure switch or the fluid level sensor.

The ALDL is located just to the right of the parking brake release handle. Refer to the manual for procedures to retrieve, read and interrupt these codes.

Take the Brake Test!

Giving your car the tests below will aid you in Troubleshooting and help you determine the General Condition of the Brakes. (Results of 30+ Reatta Systems are immediately following Test 6. Compare your results and read interpretations of Tests.) A can of DOT 3 Brake Fluid and a watch w/ a second hand may be needed. If all Blowers and Radio are off, hood is raised, you will be able to hear the Pump run w/ driver door open.

1st Test: Start car, wait a few seconds after brake lights go out for pump to run and stop. Count the number of full pedal pumps it takes to turn on the yellow and red lights. How many pumps____?

2nd Test: Climate control and radio off. Wait for lights out, then a few seconds for pump to stop running, Key off. Count the number of full pedal pumps it takes till the pedal gets very hard. How many pumps____?

Note: Now is the time to check the fluid level in the reservoir. Fill to line (Triangle).

3rd Test: Turn key on (don't start engine) Count the seconds until the red light goes out and continue counting until the pump stops running. Note also when yellow light goes out or if it doesn't. Seconds till Red light goes off_____? Yellow Light, same time?

4th Test: Total seconds till pump stops running____?

Test 5: Leave driver door open w/ hood raised. Turn key on, don't start engine. Listen and identify the brake system pump running. (under the hood, on the firewall, drivers side). Wait until the pump stops running. Depress the brake pedal one or more times until the pump starts to run. How many pumps_____? Try this several times, letting the Pump recharge the system, between tests.

Test 6 :The system should be fully pressurized ( key on, lights out, pump no longer running) and you should have filled reservoir to the fill line while the system was Depressurized , as per Manual, prior to this test! Make a mark, grease pencil, masking tape, whatever, exactly at the Reservoir fluid level. Measure the distance between the fill line and this mark.

Averages of previous systems tested

Test 1. 10

Test 2. 28

Test 3. 32

Test 4. 45-50

Test 5. 2 1/2 to 3

Test 6. 1/2 inch.

Conclusions of brake tests Results

If the Pressure Sensor is malfunctioning [shutting off the Pump before full pressure is obtained] none of the tests are valid!

Test 1. Two or three pumps to turn on RED light with engine running may suggest a weak or failing ACCUMULATOR. (Certainly the reserve pressure is LOW!)

Test 2. Few pumps to discharge system (key off) and make the pedal hard may also suggest an ACCUMULATOR problem or the system may not be building to the designed pressure, Possibly Pressure Sensor malfunction.

Test 3. A prolonged time to recharge system (to Red light out), Possible causes: faulty Pump Relay, weak pump.

Test 4. The elapsed time, if significantly shorter or longer than the average, may w/ other results, pinpoint the problem.

Test 5. Most systems w/ failing or failed Accumulators give lower than average results. 1/2 or 1 pump!

Test 6. This is a new test but over 3/4 inch is a good indicator of a failed Accumulator.

If the ACCUMULATOR has NOT lost it's charge, there will be a slow down in the speed of the pump as it charges the system. This slowdown is audible and occurs about 2/3 through the pumping cycle. A system, w/an accumulator that HAS lost its charge, will not provide the audible change in pump speed until the pumping cycle has almost completed.

Complete failure and a suggestion to replace many components, should require a second opinion. A failed accumulator, followed by a failed pump motor or pump, or both, are within reason. The appropriate Relays should also be changed when replacing a component.

 

Standard Disclaimer

Use at your own risk. The authors and those associated at Brads Reatta homepage take no responsibility for any damage resulting from any of the comments, recommendations or other direction contained herein, either implied or expressly indicated.

 

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