Hey guys,
I need to change the brake fluid in my car and thought about changing the lines to stainless steel. I've used the search feature here and it seems there is a little confusion as to whether bleeding the brakes can be done with just the motive bleeder or if you have to utilize the PST2 tester. I have referenced the Porsche repair manual and they list a procedure for:
1) Changing the brake fluid - 47 08 55
and,
2) Bleeding the brake fluid on vehicles with PSM - 47 01 07

I was under the impression that changing the brake fluid involves bleeding the fluid. In the Porsche manual, procedure 2 lists using the PST2 tester. So, the question is, does this need to be done at a facility that has the Porsche tester? I am assuming that if the brake lines are replaced than air would be introduced to the system and it will need to be properly bled to get rid of any air. Also, who sells SS replacement brake lines for the 996tt?

 

The brake flush with the PSM is the same one that should be used for all ABS/Traction Control units, it cycles the ABS pump to dislodge any air that may be trapped in the unit. You do NOT need to cycle the ABS pump to do a brake flush, unless you are having a shop that has a Porsche diagnostic tool do the work, then why not let them run the ABS cycle.

 

If I change out the brake lines then air will be in the new lines near the calipers. Will using the Motive bleeder be sufficient to evacuate the air in the new lines when bleeding the system or would the ABS pump need to be cycled in this case? Thx....

 

Yes. I just replaced the brake lines and flushed the system, as well as pads and rotors. The Porsche brake system is like any other brake system, outside of the bias. So, the Motive Bleeder will do the job. I have never cycled the ABS pump in any of my cars over the years and have never had a problem with air in the system.

That said. I would recommend flushing with 1 liter the first time. Then, after three days, re-bleed the system and you will see more gradoo come out.

 

+1, thats what I observe as well

 

Does anyone know if any of the consumer available products such as Durametric will cycle the ABS system?

 

I have not used the Durametric, I will once I get my Porsche, but it does look like you can cycle the drive link functions, which should include the ABS.

 

Very good, this makes sense. I also just got at email from the lead Porsche tech at the local Porsche dealership and he told me they always just use the motive bleeder to do the brakes, bleeding RR, LR, RF, LF, in that order. He stated that the only time they would use the PIWIS is if they change out the PSM module and needed to get the air out of the electro-hydraulic unit itself.

 

i just used the motive bleeder! worked great.. one tip i learned.

once you have the bottle filled with brake fluid build pressure in the system and allow for the fluid to flow near to the end of the attachment that goes onto the master cylinder.. otherwise you would be introducing all that air in the pipe into the system.

also do not pump the bleeder whilst the bleeder nipple is open.. i set my bleeder at around 18psi with the odd pump here and there when i finished bleeding the calipers.

i also installed ss lines!

you might also want to place a oil catch pan underneath the car for when you remove the brake line it does leak quite a bit but does not squirt out!

Mike

 

Porka, good tip about the air in the Motive tube. I had the same problem and decided to use the Motive bleeder dry. It was easy to bleed one corner at a time without having to refill the reservoir. A tight pedal every time.