PSM and Brake Flushing?

[Bk4205]

Ok, I have read that some Porsche owners that own 996's with the PSM option have done brake flushing without out the use of a PC based diagnostic tool to activate the electronics in the braking system, some state it is also necessary to use the diagnostic software?

I have ordered the Durametric cable for my 2002 996 Carrera along with a refurbished laptop off of EBay for the purpose of working on the car and was told by the folks at Durametric that this is one of the functions that the program can provide. What is actually being turned ON during the flushing event using a software diagnostic tool such as Durametric?

Brad

[Loren]

The hydraulic system return pump is being actuated.

Here is the procedure:

- Preliminary work: Bleed brakes as usual

- To bleed the ABD circuit, the bleeding device remains connected (switched on).

Bleed pressure approximately 1.5...2.0 bar.

- Connect the Porsche System Tester 2 to the diagnostic socket. (Durametric in your case)

- Open the rear right bleeder valve (use collecting bottle).

- Press the Start button on the System Tester.

This initiates certain functions in the hydraulic control unit (return pump, switch-off and switch-over valves are actuated).

- Bleed until clear, bubble-free brake fluid emerges.

In addition (throughout bleeding operation) fully depress (pump) brake pedal as far as the stop at least ten times.

Caution: In vehicles with high mileage or in old vehicles, double the pumping cycles and use only half the brake master cylinder stroke (damage to the brake master cylinder could result / primary boot damage).

- Close the right rear bleeder valve. Then immediately press Stop button on the System Tester.

- Switch ignition off and disconnect System Tester.

- Switch off and disconnect bleeder device.

- Correct brake fluid level if necessary.

To reiterate you really only need to do this procedure if the brake system has been opened (i.e. new lines), components have been replaced (i.e. ABS pump), or you are changing from or to synthetic brake fluid.

[JFP in PA]

Ok, I have read that some Porsche owners that own 996's with the PSM option have done brake flushing without out the use of a PC based diagnostic tool to activate the electronics in the braking system, some state it is also necessary to use the diagnostic software?

I have ordered the Durametric cable for my 2002 996 Carrera along with a refurbished laptop off of EBay for the purpose of working on the car and was told by the folks at Durametric that this is one of the functions that the program can provide. What is actually being turned ON during the flushing event using a software diagnostic tool such as Durametric?

Brad

As Loren noted, cycling the ABS/PSM systems is only required if you have replaced major components in the ABS or PSM system, or gotten air into them; otherwise it is not necessary. Even dealerships do not cycle these systems during a flush unless specifically needed.

[Bk4205]

As always, thanks for the reply to my questions. I now understand how to proceed with this small task at hand and my car will be much happier if only it had feelings! Glad that I have a wonderful resource to draw knowledge from on the Porsche topics that are all new to me. Probably hooked for life now that I have my first 911 (996).

Brad