Brake/Clutch Fluid Change and Bleeding Instructions

[Loren]

Done something stupid tonight...

I replaced my brake fluid in the fall, but didn't do the clutch. I wasn't aware of how to do it back then. But, following the DIY threads here, I decided to tackle the clutch today.

Holy begeezus that's a tight fit! I was able to contort my arm enough to get the rubber hose on the valve and open it up with a wrench. All went well and as I went to refill the reservoir, I accidentally grabbed my can of CHF202 and poured approximately 1/2 to 1 ounce in the reservoir until I finally noticed the can didn't look right.

The CHF202 and ATE Blue are in similar shape/size cans and were sitting right next to each other on my shelf. I grabbed the wrong freakin' can...

So, took a medicine syringe and sucked out as much of the fluid I could from the reservoir. The fill indicator says it was just below MIN so I didn't empty all the fluid out to avoid getting air in the system.

Am I safe? Or is the mixing so bad that I need to do a complete brake fluid flush? If the specific gravity of Pentosin is lighter than the Ate, then I think I've got it all up. If the Pentosin is heavy, then it probably settled in the bottom of the reservoir. :(

What do you guys think?

If you did not press the pedal or do any bleeding then I think you are likely ok.

Did the two fluids mix?

If so, you might want to add some brake fluid then suck it back out too - before refilling.

[bar10dah]

Nope, didn't use the brakes or flush yet. Just pulled about half the fluid out of the reservoir.

From what I've been reading online, the power steering fluid is lighter than the brake fluid, so it should be sitting on top, and hasn't mixed. The problem is, with that small opening in the reservoir, how can I adequately pull out all the contaminated fluid?

I'll refill and suction out the fluid a couple more times, but not sure it'll be enough to pull that top layer off. However, if that top layer does indeed always remain on top, then I shouldn't ever have the possibly contaminated fluid enter the brake system as I never run my fluid so low that the top layer gets pushed into the brake lines.

At this point, should I still go ahead and do the flush? Or just exchanging the fluid in my reservoir should be adequate?

[Loren]

I think exchanging all the fluid in your reservoir should be fine.

[bar10dah]

Refilled with Ate Blue, sucked the fluid out (skimming the top), with a medicine syringe, down to below the MIN line. Refilled with Napa DOT 4 and skimmed the fluid again. Refilled with Napa again, all the way to the top, hoping to get the oil to float to the filler neck so I can get at it better. I'll go back out soon and see how it looks. But at this time, there's no sheen on the top. So I'm guessing no oil?

Also, from the photos, the very top layer (1/8"?) is darker than the rest. I'm guessing that's the CHF202. But, looking in the bottle, there's no sheen.

UPDATE: Didn't want to chance it, so pulled the reservoir out. Cleaning it up now and will reinstall soon. If the fluid level didn't fall below the rubber grommets on the master cylinder, I should be fine without having to bleed?

Edited June 14, 2012 by bar10dah

[Henrik68]

Hi

I will replace my brake lines and then i will have air in to my system, or? How do i do to get all air out? I us a power bleeder.

[VanSoetaert]

Thanks for all the great info.

Relating to my 2008 Cayenne S, how much new fluid will I need for a complete flush, and is it unnecessary to bleed the ABS? Would the dealer bleed the ABS?

[JFP in PA]

Thanks for all the great info.

Relating to my 2008 Cayenne S, how much new fluid will I need for a complete flush, and is it unnecessary to bleed the ABS? Would the dealer bleed the ABS?

Many dealers do not even activate the ABS/PSM pumps during a standard flush unless there is a lot of air in the system or they are replacing major system components, so you should not need to either. You will need a bit over one liter of fluid.

[wyovino]

Hi,

I'm about to replace pads and rotors all around and also need to flush the brake fluid. Is there a benefit to doing one of those procedures before the other?

If I can't find the brands of brake fluid mentioned in the DIY, can I use any DOT 4 brake fluid?

[JFP in PA]

Hi,

I'm about to replace pads and rotors all around and also need to flush the brake fluid. Is there a benefit to doing one of those procedures before the other?

If I can't find the brands of brake fluid mentioned in the DIY, can I use any DOT 4 brake fluid?

It would probably be best to flush and bleed the system last to minimize any chance of problems. Be sure to properly bed your new pads and rotors when everything is done.

Which fluid you use is important; we strictly use the ATE brand at the shop due to its high boiling points and excellent performance history. Look around a bit, a lot of retailers that focus on the performance market carry it, and it is readily available online as well.

[jjb7]

I just replaced the brake fluid as required for track days. Here are some notes: I used a 1/4" ID tube, a 3/16" would have been better. The original fluid was clear yellow and so was the replacement. So I calculated that since I had 3 feet of hose, 3 complete hosefuls would equal the volume of fluid held by the brake lines in the longest section of pipe (RR). Also, since the ID of brake lines in 1/8" the 1/4" bleed tubes hold 4 times the volume. This extra volume is used for the pistons. Porsche states the brake system capacity is .4 L. I used .75 L.

I held the tube straight up until it filled, then closed the valve, dumped the fluid, and repeated. A MightyVac is a great tool to evacuate the fluid reservior. This initial fluid leaving the pistons was cloudy with bubbles. This inital spongenous of pedal travel is gone. Now there is a noticeable sharp bite after the first 1 1/2" of travel. I used Pentosin for track use, but any DOT 4 will work for daily driving.

[DK570]

What fluid is everyone using? I had planned to switch to blue fluid when I flushed the system to easily identify the new stuff, but that's no longer an option. I recently posted this chart on another forum:

I guess because of the ABS system, SL6 would be the preferred fluid?

[JFP in PA]

ATE Type 200 is fine, the SL6 is for specific applications requiring low viscosity fluid such as extreme cold climates. You can use the SL6 in your car, but it won't offer any specific advantages over the Type 200 and does have lower boiling point characteristics.

[Sniff]

You are using a pressure bleeding system (like Motive) so you bleed the clutch with the pedal depressed to clear - then with it in normal position -- then close the valve.. Same rules as brakes wait until it is clear and bubble free.

Then bringing the pedal up very slowly assures that you do not cavitate or otherwise pull air into the system - close the valve as the fluid runs clear and bubble free.

Loren, thanks so much for the reply. I'm obviously being a bit slow today - could you just confirm: Pedal held down Open valve Clear fluid emerges Pump pedal as per instructions Clear fluid emerges (after 90 secs) Close valve OR Pedal held down Open valve Clear fluid emerges CLOSE VALVE Pump pedal as per instructions OPEN VALVE Clear fluid emerges (after 90 secs) Close valve Thanks again, Andy

Pedal held down

Open valve

Clear fluid emerges

Pump pedal as per instructions

Clear fluid emerges (after 90 secs)

Close valve

This is correct following the wait and slowly releasing the pedal.

Loren, I think I am having the same issues as Andy. These steps don't make sense to me . . . specifically pumping the clutch pedal when the bleeder valve on the clutch slave cylinder is OPEN. How do you NOT introduce air into the system on the return stroke of the clutch pedal? If you are using a power fill, the system is under pressure. So what is the point of pumping the pedal? Won't all the old fluid exit the system (assuming the clutch is fully depressed and held) just by the pressure of the power fill? Thank you.

Sean

[JFP in PA]

You are using a pressure bleeding system (like Motive) so you bleed the clutch with the pedal depressed to clear - then with it in normal position -- then close the valve.. Same rules as brakes wait until it is clear and bubble free.

Then bringing the pedal up very slowly assures that you do not cavitate or otherwise pull air into the system - close the valve as the fluid runs clear and bubble free.

Loren, thanks so much for the reply. I'm obviously being a bit slow today - could you just confirm: Pedal held down Open valve Clear fluid emerges Pump pedal as per instructions Clear fluid emerges (after 90 secs) Close valve OR Pedal held down Open valve Clear fluid emerges CLOSE VALVE Pump pedal as per instructions OPEN VALVE Clear fluid emerges (after 90 secs) Close valve Thanks again, Andy

Pedal held down

Open valve

Clear fluid emerges

Pump pedal as per instructions

Clear fluid emerges (after 90 secs)

Close valve

This is correct following the wait and slowly releasing the pedal.

Loren, I think I am having the same issues as Andy. These steps don't make sense to me . . . specifically pumping the clutch pedal when the bleeder valve on the clutch slave cylinder is OPEN. How do you NOT introduce air into the system on the return stroke of the clutch pedal? If you are using a power fill, the system is under pressure. So what is the point of pumping the pedal? Won't all the old fluid exit the system (assuming the clutch is fully depressed and held) just by the pressure of the power fill? Thank you.

Sean

Pumping the pedal while the system is under pressure and the bleeder is open moves the internals of the clutch master cylinder back and forth to clean out any residual fluid in the master while the pressure system keeps clean fluid flowing through. It is in the bleeding instructions found in the OEM service manuals for these cars.

[Sniff]

Thanks for the response JFP. When it comes to using the Powerfill, some people choose to keep the tank empty and just use it as a pressure source connected to the brake fluid reservoir (the only fluid they work with is what is contained in the reservoir). This technique of course requires repeated checks to make sure the fluid in the reservoir doesn't get too low, but the plus is you don't have to wash out your Powerfill tank once the job is done. Others actually fill the Powerfill tank and push fluid through the hoses into the brake fluid reservoir.

So my question is, will 10-15 cycles of the clutch pedal deplete the quantity of fluid in the brake reservoir (assuming it is completely full)? Will I be forced to fill my Powerfill tank with fluid to prevent depleting my brake reservoir during the clutch bleed process? I hope that makes sense. Much appreciated.

Sean

[JFP in PA]

Thanks for the response JFP. When it comes to using the Powerfill, some people choose to keep the tank empty and just use it as a pressure source connected to the brake fluid reservoir (the only fluid they work with is what is contained in the reservoir). This technique of course requires repeated checks to make sure the fluid in the reservoir doesn't get too low, but the plus is you don't have to wash out your Powerfill tank once the job is done. Others actually fill the Powerfill tank and push fluid through the hoses into the brake fluid reservoir.

So my question is, will 10-15 cycles of the clutch pedal deplete the quantity of fluid in the brake reservoir (assuming it is completely full)? Will I be forced to fill my Powerfill tank with fluid to prevent depleting my brake reservoir during the clutch bleed process? I hope that makes sense. Much appreciated.

Sean

I always get a chuckle out of people trying to save time by defeating the purpose of a tool. You might be surprised at how many cars we see flat bedded into the shop because someone tried to "save the time required to clean out" their Motive pressure tank. If you miss on keeping the fluid level up in the reservoir, which alone has to be more effort and time than cleaning the tank on the Motive unit, you are going to introduce air into your ABS/PSM control system, which requires the use of a PST II/PIWIS/Durametric system to get it out. While we do make a lot of money off other's mistakes, I still suggest you use the tool as it was designed. We have multiple Motive units in the shop; it takes about 5 min. to fully clean one after using it. The flat bed and shop time to fix it if you guess wrong cost a bit more.

As I have never done what you are describing, I have no basis to answer your question about if pumping the pedal will empty the reservoir, but based upon the size of the system reservoir and the volume of fluid the clutch master pushes out per pump, I would guess that it would not empty it completely.

[Sniff]

JFP,

That makes sense. I just received my Motive Powerfill and wanted to get all my questions out of the way before attempting my first brake and clutch fluid flush on my new-to-me 997.1. I think I will use it as it was designed -- put 2 quarts of fluid in the tank and not worry about having to check the reservoir all the time. Come to think of it, I will end up throwing all the leftover brake fluid in the tank away since the next time I'll do this is in 2 years. I won't be saving anything by not putting it all in the tank.

Sean

[leonidasb22]

This is the support topic for the DIY Tutorial Brake/Clutch Fluid Change and Bleeding Instructions. Please post here if you have any questions or feedback.

 

 

I have some questions regarding the Clutch Bleeding portion of this tutorial. 

 

How do you know if you need to bleed your clutch? Are there signs that this needs to be done? 3 weeks ago I bled my brakes with the Motive Power Bleeder but I didn't do the clutch bleeding. Should I go back and do this? Or is there a test I can do to know if my clutch needs to be bled? 

 

I have a 2004 996 with manual transmission.

 

And just so I get a better understanding...the clutch uses brake fluid and the brake system master cylinder to operate? 

 

Thanks in advance. 

[JFP in PA]

 

This is the support topic for the DIY Tutorial Brake/Clutch Fluid Change and Bleeding Instructions. Please post here if you have any questions or feedback.

 

 

I have some questions regarding the Clutch Bleeding portion of this tutorial. 

 

How do you know if you need to bleed your clutch? Are there signs that this needs to be done? 3 weeks ago I bled my brakes with the Motive Power Bleeder but I didn't do the clutch bleeding. Should I go back and do this? Or is there a test I can do to know if my clutch needs to be bled? 

 

I have a 2004 996 with manual transmission.

 

And just so I get a better understanding...the clutch uses brake fluid and the brake system master cylinder to operate? 

 

Thanks in advance. 

 

 

Both the clutch and the brakes share a common fluid reservoir, so when you bleed the brakes, you should also do the clutch at the same time.

[leonidasb22]

 

 

This is the support topic for the DIY Tutorial Brake/Clutch Fluid Change and Bleeding Instructions. Please post here if you have any questions or feedback.

 

 

I have some questions regarding the Clutch Bleeding portion of this tutorial. 

 

How do you know if you need to bleed your clutch? Are there signs that this needs to be done? 3 weeks ago I bled my brakes with the Motive Power Bleeder but I didn't do the clutch bleeding. Should I go back and do this? Or is there a test I can do to know if my clutch needs to be bled? 

 

I have a 2004 996 with manual transmission.

 

And just so I get a better understanding...the clutch uses brake fluid and the brake system master cylinder to operate? 

 

Thanks in advance. 

 

 

Both the clutch and the brakes share a common fluid reservoir, so when you bleed the brakes, you should also do the clutch at the same time.

 

 

Hi JFP in PA—

 

Ok, but since I just did the brake bleeding and brake flush 3 weeks ago, should I do it again to get the clutch bled? How do I know if i have air in the clutch?

[Loren]

Just do the clutch bleed now. It is okay to do it last.

[Octane4evr]

There are lots of Motive models out there, which one is right for a 996?

[JFP in PA]

58 minutes ago, Octane4evr said:

There are lots of Motive models out there, which one is right for a 996?

 

Any Motive model will work, what you need is the correct adaptor for your car, witch would be either #1100 or 1109.

[Engelkraut]

i ran out of brake fluid while bleeding the caliber on the last wheel (front/left).  the reservoir went dry and i sucked air in.  can i simply start the process over (to get the air out) or will i need to bring it in somewhere to have air sucked out of the psm system?  any help would be appreciated.

[JFP in PA]

What will need to be done is rebleed the system with the ABS/PSM pump activated, which will require a Porsche specific diagnostic too