Brake/Clutch Fluid Change and Bleeding Instructions

[Loren]

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Brake/Clutch Fluid Change and Bleeding Instructions

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Note: Part numbers sometimes change without notice. Always double check with your supplier that you have the latest part numbers. (Edit - July 25, 2006 - Updated the clutch bleeding procedure to the latest procedure as outlined in supplement 98 of the Carrera Service Manual - Loren) Parts you will need: 1 liter (minimum) 000 043 203 66 Porsche DOT 4 Brake Fluid or equal (ATE Gold or ATE Super Blue) Tools you will need: Jack 19 mm socket for wheel bolts Motive Power Bleed

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• Author
  Loren
• Category
  Carrera (996) - Maintenance
• Submitted
  11/16/2005 07:02 AM

 

[Long Islander]

Thanks to the RennTech DIY instructions and others on this board, I bled my brake fluid today. The instructions were very helpful.

Here are a few other tips I can pass along to anyone else who plans to do this.

Drain tube:

You should buy 2 feet of clear plastic tubing, 3/16" inner diameter, 5/16" outer diameter. The tubing needs to be clear so you can see if there are any air bubbles in the fluid that's being drained. Less than 2 feet will leave the end of the tube dangling, and you'll have to hold your drainage jar with one hand and the end of the tube with the other hand.

Drain jar:

Obtain a glass jar (tomato sauce or apple sauce jars are perfect) that has at least a 1/2 liter capacity and mark the level in advance for 250 ml and for 500 ml. Save the lid. Drill a 5/16" diamer hole in the lid. The drainage end of the drain tube will fit perfectly in the hole you drilled in the lid and you won't have to hold either one. Also, when disconnecting the tube from the nipple, the other end will just drain into the jar and you won't spill a drop of fluid anywhere.

Turkey baster:

The instructions have you using a turkey baster to remove fluid from the reservoir. Well, the turkey baster my wife gave me was way too wide at the tip to fit around the little pieces of plastic that blocked access to the bottom of the reservoir (yes, I did remove the screen). I'm not sure if they make smaller turkey basters, but the tip has to be thin enough to fit into a small slot at the side of the opening to the reservoir and get way down to the bottom.

Instead of a turkey baster, what I did worked really well and was probably much quicker. I used a clean plastic pump from a liquid soap or lotion dispenser, with a flexible but stiff tube attached to the bottom. I was able to push the end of the tube down the side of the opening inside the brake fluid reservoir, and pump the brake fluid into an empty water bottle.

Brake fluid:

Have at least 2 liters of brake fluid available. I used all 2 liters.

Oh, and BTW, the used brake fluid that came out of the car didn't look anything like the nice, clear slightly yellow ATE gold fluid that I put in. It was definitely time.

[wce]

I'll add a key point to keep in mind: the bleeder valve CAN introduce air into your drain tube when the fluid is flowing! This will give the appearance of air coming out of the caliper when in fact it is seeping in past the valve threads. You only need to open the valve about a quarter turn, much more will guarantee some air bubbles. If you have this problem, you can prove it's being introduced at the valve by pushing the valve in, sealing the threads. If the air bubbles stop - there's your source. When your done make sure the valve is securely closed!

I would also recommend using the Motive pressure bleeder with air only. The unit's cap strangely doesn't have a gasket, and while it seemed to hold pressure, it did leak significant fluid when I used it "wet". Using air pressure keeps it clean, just don't risk letting the fluid level drop much below "min". I would say 2 refills (from just below min to top of the cap) for each rear brake and one for each front should be sufficient for a normal flush. I would also recommend the slightly more expensive "black label" unit with the swivel fitting if you plan on doing this often!

Finally, below the reservoir inlet screen in most cars is the notoriously faulty float switch for the low fluid indicator. This blocks access by any turkey baster I've ever seen. The solution above seems like it should work, I just pumped the fluid level lower, although at the risk of getting air into the system.

Happy bleeding!

Edited June 14, 2007 by wce

[wwest]

Does Porsche not have a "bleed valve" at the ABS manifold/pumpmotor assembly? Both of my Lexus vehicles, '92 LS and '01 RX, do. Actually the '92 has two additional ones, one at the ABS pump/manifold and another at the Trac pump/manifold/accumulater.

Absent that extra bleed valve you'll need to get the Porsche's ABS/PSM/Trac pumpmotor to activate for an extended period of time to get the "old" brake fluid to flow out of "those" brake line sections. My '92 even has a 3000 PSI nitrogen filled accumulator that holds a substantial level of brake fluid that must also be "bled".

Even with the extra fittings, valve(s), the Lexus "techie" who did my '92 put it on a rack and "drove" the rear wheels for a minute or so to get the Trac system to activate and force fluid flow in from/into those line sections.

Edited August 25, 2007 by wwest

[Loren]

Does Porsche not have a "bleed valve" at the ABS manifold/pumpmotor assembly? Both of my Lexus vehicles, '92 LS and '01 RX, do. Actually the '92 has two additional ones, one at the ABS pump/manifold and another at the Trac pump/manifold/accumulater.

Absent that extra bleed valve you'll need to get the Porsche's ABS/PSM/Trac pumpmotor to activate for an extended period of time to get the "old" brake fluid to flow out of "those" brake line sections. My '92 even has a 3000 PSI nitrogen filled accumulator that holds a substantial level of brake fluid that must also be "bled".

Even with the extra fittings, valve(s), the Lexus "techie" who did my '92 put it on a rack and "drove" the rear wheels for a minute or so to get the Trac system to activate and force fluid flow in from/into those line sections.

Porsche's method to bleed the ABS is to hookup a PST2 or PIWIS tester and use a built-in function that starts the ABS pump during bleeding.

[jsoto]

Loren - great instructions again.

Please add another step to your procedure.

- Don't forget to replace the plastic screen in the reservoir when finished.

[BlueJay73]

Does Porsche not have a "bleed valve" at the ABS manifold/pumpmotor assembly? Both of my Lexus vehicles, '92 LS and '01 RX, do. Actually the '92 has two additional ones, one at the ABS pump/manifold and another at the Trac pump/manifold/accumulater.

Absent that extra bleed valve you'll need to get the Porsche's ABS/PSM/Trac pumpmotor to activate for an extended period of time to get the "old" brake fluid to flow out of "those" brake line sections. My '92 even has a 3000 PSI nitrogen filled accumulator that holds a substantial level of brake fluid that must also be "bled".

Even with the extra fittings, valve(s), the Lexus "techie" who did my '92 put it on a rack and "drove" the rear wheels for a minute or so to get the Trac system to activate and force fluid flow in from/into those line sections.

Porsche's method to bleed the ABS is to hookup a PST2 or PIWIS tester and use a built-in function that starts the ABS pump during bleeding.

So, is the bleeding procedure incompletely done if the ABS pump is not bled? Does the car have to go to the dealer anyway, to hook it to the PIWIS for ABS bleed? If the ABS has to be bled, any way to do it without the dealer or a PIWIS?

[Loren]

So, is the bleeding procedure incompletely done if the ABS pump is not bled? Does the car have to go to the dealer anyway, to hook it to the PIWIS for ABS bleed? If the ABS has to be bled, any way to do it without the dealer or a PIWIS?

Most dealers do not both to bleed the ABS unless the system has been open (i.e. lines or components replaced).

I have a PST (and PIWIS) and and I usually do not bleed the ABS on my own car.

[BlueJay73]

So, is the bleeding procedure incompletely done if the ABS pump is not bled? Does the car have to go to the dealer anyway, to hook it to the PIWIS for ABS bleed? If the ABS has to be bled, any way to do it without the dealer or a PIWIS?

Most dealers do not both to bleed the ABS unless the system has been open (i.e. lines or components replaced).

I have a PST (and PIWIS) and and I usually do not bleed the ABS on my own car.

Thanks.

I'd like to be your next door neighbor! (Can I borrow a cup of sugar, and the PIWIS?)

[jsoto]

oggie - I used the plastic pump as well and it worked great. I would recommend this method. I only had about 1ft. of plastic tubing and wish it were 2-3 feet especially for the transmission. I had to hold the bottle when I bled the brakes. It was not convenient. I used about 1.25 liters of fluid for my car. I used the Blue fluid and it was easy to see the new fluid coming out.

If seemed that it took awhile for the clean fluid to come out the RR tire (expected), but it also took some time for the right front to clear up. (that seemed odd). My car has 25k miles on it (MY03) and the brakes had never been bled. Previous owner did not do it (I purchased car about 6 months ago). The fluid was dirty, but not as dirty as expected (it was time though).

All in all, the job did not take long to do. While the tires were off, I cleaned them and waxed them.

Great instructions Loren.

[Fast Forward Wheels]

Can anyone provide more info on the PST and PIWIS for me and the cost of these items?

Thanks,

[Loren]

Can anyone provide more info on the PST and PIWIS for me and the cost of these items?

Thanks,

:welcome:

You don't want to know... :o

I bought a used PST2 for about $3600.

A PIWIS lease is $18,000 for the first year and $12,000 per year thereafter.

[ArneeA]

Loren, the transmission for a 996TT is simliar to a 996 N/A? I ask because I wonder if a clutch bleed valve is in the same position as my 996 N/A.

Thanks.

[Loren]

Loren, the transmission for a 996TT is simliar to a 996 N/A? I ask because I wonder if a clutch bleed valve is in the same position as my 996 N/A.

Thanks.

Yes, it is similar. It still sits high on the transmission near the bell housing.

Remember PentoSin for the clutch circuit on TT/GT2.

[ArneeA]

Loren, the transmission for a 996TT is simliar to a 996 N/A? I ask because I wonder if a clutch bleed valve is in the same position as my 996 N/A.

Thanks.

Yes, it is similar. It still sits high on the transmission near the bell housing.

Remember PentoSin for the clutch circuit on TT/GT2.

Ah thanks. I'm sorry but Pento-who? The 996TT DIY section is empty... I can't find any info. It's for a friend's car and I'll be helping him with the fluids.

[Loren]

Loren, the transmission for a 996TT is simliar to a 996 N/A? I ask because I wonder if a clutch bleed valve is in the same position as my 996 N/A.

Thanks.

Yes, it is similar. It still sits high on the transmission near the bell housing.

Remember PentoSin for the clutch circuit on TT/GT2.

Ah thanks. I'm sorry but Pento-who? The 996TT DIY section is empty... I can't find any info. It's for a friend's car and I'll be helping him with the fluids.

Look in your Owners Manual the clutch and power steering use only Pentosin CHF 202 (Pentosin CHF 202 supersedes CHF 11S and they can be mixed).

[ArneeA]

Loren, the transmission for a 996TT is simliar to a 996 N/A? I ask because I wonder if a clutch bleed valve is in the same position as my 996 N/A.

Thanks.

Yes, it is similar. It still sits high on the transmission near the bell housing.

Remember PentoSin for the clutch circuit on TT/GT2.

Ah thanks. I'm sorry but Pento-who? The 996TT DIY section is empty... I can't find any info. It's for a friend's car and I'll be helping him with the fluids.

Look in your Owners Manual the clutch and power steering use only Pentosin CHF 202 (Pentosin CHF 202 supersedes CHF 11S and they can be mixed).

Gotcha. Thanks.

[KenJ]

Loren,

Sorry, I got confused on one part of the optional clutch bleeding... "Remove the wood. Then, pump the pedal again very slowly by hand for a further 60 seconds. After pressing the pedal down fully about 10 to 15 times, leave the pedal in its normal position." What is the normal position? I chose to end the pumping at the full up position, but did you mean in the down position because that's where the clutch pedal started the procedure?

thanks,

kj

[Loren]

Loren,

Sorry, I got confused on one part of the optional clutch bleeding... "Remove the wood. Then, pump the pedal again very slowly by hand for a further 60 seconds. After pressing the pedal down fully about 10 to 15 times, leave the pedal in its normal position." What is the normal position? I chose to end the pumping at the full up position, but did you mean in the down position because that's where the clutch pedal started the procedure?

thanks,

kj

Normal position is with the pedal up.

[gandrade1]

Getting ready to bleed the brakes!

Quick questions from a first timer:

(1) Can I just jack the car up one wheel at a time or do I need to put it on stands? My garage is tight and using 4 stands at the same time is a challenge...

(2) How do the bleeding valves open and how do I tighten them up with the 'bleeding tubes' connected to them? Do I need any tool?

(3) How much fluid should I pump out of the reservoir before I fill it up with new fluid? I am also thinking about using the pump from a liquid soap or something.

(4) What can go wrong and how do I know if the bleeding worked, before I put the car back on the road?

Thanks as usual,

Gustavo

:renntech:

Edited March 19, 2008 by gandrade1

[Loren]

1. Yes, you can do one wheel at a time - in the proper sequence.

2. A small wrench will work fine.

3. You will need less new brake fluid (less intermixing) if you remove most of the old fluid from the reservoir first.

4. You should see no bubbles when the fluid is coming out bleed valve. If you see bubbles then it is not yet clear of air. You should have a nice firm brake pedal.

[gandrade1]

1. Yes, you can do one wheel at a time - in the proper sequence.

2. A small wrench will work fine.

3. You will need less new brake fluid (less intermixing) if you remove most of the old fluid from the reservoir first.

4. You should see no bubbles when the fluid is coming out bleed valve. If you see bubbles then it is not yet clear of air. You should have a nice firm brake pedal.

Thanks, Loren

Is it a problem if I need to move the car (i.e. use the brake) between bledding one wheel and another to get more space in my garage?

Will a jack work or do I need to put stands (I am not bleeding the clutch)?

Best,

Gus

[Loren]

If you need to move the car between the brake bleeding of each wheel - the only reliable brake you will have will be the hand brake. Please be very careful if you decide to do that.

If you don't use jack stands - then for safeties sake put the tire/wheel under the car while you work on it.

[gandrade1]

Hi guys,

Gathered all the tools, bought the bleeder and am trying to start the bleeding on my 01 Boxster right now...and already have a question (sorry).

I opened the fluid reservoir and removed the first screen (please see pic below), but even after I did I have something on the way (looks like a small fluctuating ball - is it the fluid level sensor?)

Do I need to remove anything else?

I dont see how I can remove fluid with that thing on the way...

Thank you so much....

Gus

[gandrade1]

I'll add a key point to keep in mind: the bleeder valve CAN introduce air into your drain tube when the fluid is flowing! This will give the appearance of air coming out of the caliper when in fact it is seeping in past the valve threads. You only need to open the valve about a quarter turn, much more will guarantee some air bubbles. If you have this problem, you can prove it's being introduced at the valve by pushing the valve in, sealing the threads. If the air bubbles stop - there's your source. When your done make sure the valve is securely closed!

Apparently I had this problem yesterday and waited too long for the bubbles to clean - ran out of fluid in the last wheel and will have to start over... :cursing:

I am not sure I understand the test you suggest above - pushing the valve in, sealing the threads. What are you suggesting we push in?

Thanks,

Gus