Replacing Brake Fluid on a 997.2

[tcouture]

I want to replace the OE fluid with Motul RBF600. I use a motive pressure bleeder if it makes any difference.

I have a couple of questions regarding the procedure:

1. How do you flush the the clutch slave cylinder? I had a 996 before and there was a bleed nipple on the transmission housing neer the clutch. Looks like that is gone on the 997.2 and there is a return line attached where the bleeder used to be (looking at PET)... (should be in doc od 47085500)

2. I read somewhere that you do not need to actuate the ABS pump on the 997.2 to flush the brake fluid like we used to before, is that true? I have a durametric but, if it is not needed due to a new design, it just makes things easier... (should be in doc id 300107)

I was trying to get the docs from PIWIS-TIS but they do not want my money at the moment - I get a "the payment provider is down" message.

Any help is appreciated,

T.

Edited March 28, 2011 by tcouture

[Loren]

1. Follow the procedure in the DIY Tutorial section here.

The bleeder is still mounted up high on the transmission as I recall. The bleeder valve is the top fitting.

2. You will need to completely flush the whole system since you are going from conventional brake fluid to a synthetic brake fluid. The two are not miscible so a complete flush is in order (including the ABS/PSM).

[tcouture]

Thanks Loren. This is a good one...

As you indicated, I am making this more complicated because I need to flush all the brake fluid to replace it with a different type - I really need to take all of it out...

I am looking at PET 997-2 illustration 301-05 from which I believe you got your diagram, and it looks like pos #1, the "clutch operating cylinder" can also be referenced in illustration 702-08 as pos #22 (see attached).

This is where it gets a little bit more complicated... On that page, you will clearly see that there is a return line (pos #23) connecting to the top position, after the bleeder valve. I probably also need to flush that return line.

Looking at WM 300107 "Bleeding the clutch system - as of model year 2009" they seem to be using a special tool (#9781) that couples to the return line - essentially adding a bleeder to the line so it can be bled before reattaching it to the clutch slave cylinder.

Because I do not have the tool, I will try to track it down but since this is a one time thing, I am wondering how I could accomplish this without it... Since the slave cylinder is below the fluid reservoir, I can probably just fill it up and let gravity flush the line for me - but a cleaner solution would probaby be better :)

Any toughts are welcome.

Thanks,

T.

P.S: Also note that there is no reference to the ABS system in the 997-2 document WM 470855 "Replacing brake fluid" while it is there in the 997 section in WM 470107 "Bleeding the brake system"... 470107 is not listed when I do a search based on 997-2 vehicle type. Would that mean that the procedure changed and that ABS flushing is not required anymore? I am new to the Porsche WM and it is all a little cryptic.

Edited March 29, 2011 by tcouture

[Loren]

Odd that the two diagrams are not consistent.

Have you looked on the car to see what is actually there?

[tcouture]

Thanks Loren.

Going under is my next move but won't be able to get to it before the weekend. I is still below freezing up here so jacking up the car outside is not something I am looking forward to at this juncture, hopefully it will warm up. I will report back with the results.

Also, it looks like I was editing my post while you answered, did you see the ABS bleeding comment regarding the changes in the WM? weird.

Regards,

T.

Edited March 29, 2011 by tcouture

[Loren]

Are you looking at the 997-1 manual?

I think the best thing to do would be to turn on the PIWIS on 997-2 and see if the ABS bleed option comes up. I think it likely will as repairs to the ABS/PSM systems or any line replacements would require a complete flush.

If I turn on my PIWIS in demo mode it does show the option - but sometimes you have to be connected to a real car to see what options are available for "that car".

[tcouture]

Are you looking at the 997-1 manual?

I think the best thing to do would be to turn on the PIWIS on 997-2 and see if the ABS bleed option comes up. I think it likely will as repairs to the ABS/PSM systems or any line replacements would require a complete flush.

If I turn on my PIWIS in demo mode it does show the option - but sometimes you have to be connected to a real car to see what options are available for "that car".

I'm with you on that one... I think it is just an oversight in the manual since the 997/987 manual do have this section about bleeding, just not the 997.2. BTW, the option to actuate the pumps is there for the Durametric tool for a 997-2 with SW 6 Beta.

I am starting to think that this will make for an interesting DYI document once I have all the nooks and crannies figured out... The good news is that the dealer is 1/2 mile away if I completely mess it up :).

Cheers,

T.

Edited March 29, 2011 by tcouture