Stupid questions re: brake bleeding

So I just finished swapping front pads and rotors and all is great, except that for some reason this procedure seems to have agitated the brake fluid and when I looked at it as I finished up my pad and rotor swap, the fluid in the resevoir was very dark in color. So, I'm pretty sure its due to be replaced. So here are my two questions: (1) I would like bleed my brakes this weekend (next week will be too busy to do it), and thus won't have time to order a motive power bleeder. I've seen lots of instructions for how to bleed the brakes using this tool, but how does one do so by using the brake pedal (I have access to a helper). Does anyone know where there are instructions for bleeding the brakes the old fashioned way? (FYI, I've never once bled brakes in my life, and in fact, last night was the first pad/rotor change I've ever done also). Besides time and needing a helper, any real downside to bleeding without a power bleeder? (2) Besids the fluid I can buy at the dealer, is their an acceptable, lower-priced subsitute? I've seen references to "ATE Blue" and whatnot, but I haven't seen any other specs. What exactly should I get, and where can I get it? Sorry for the newbie questions, and thanks in advance for any advice. Scott.

Suggest you visit Renntech.org for tips on brake bleeding. It's pretty simple with a helper. As for fluids, ATE Super Blue is good, as is Motul 600. I believe that ATE Gold is OEM for P-cars. Both ATE and Motul can be difficult to find, probably not stocked at your local Pep Boys or Kragen. Most racing or high-performance shops will have one or the other. Brake fluid should be completely replaced every two years (assuming normal use) as it does pick up water over time.

Porsche service manual states you are not to bleed these brakes through the traditional push/pedal method. They are to only be bled at high pressure (around 1.5 bar or 22 psi) with a remote fluid reservoir.

Hey guys, thanks for the tips. Looks like a may be ordering the bleeder and waiting, unless someone has any hints about where to find one at brick and mortar store.

I've always bled my brakes via the traditional pump-the-pedal method. Anyone have any idea why Porsche recommends against it? Have I totally trashed my brake system? Car still stops.

Scott, I bought the power bleeder and preferred the old fashioned method. Call me at [phone removed]....or try this method.... My kids really enjoy helping me with this job because they get to sit in the driver's seat. Start with the caliper furthest away. Jack up that corner and remove the wheel. Put a clear tube of the appropriate diameter and length (18 inches long is about perfect) on the outer bleed nipple (after removing the dust cap). Run the tube into a 12 oz or larger clear glass jar. Make sure the reservoir is full. Open the bleed nipple and tell your helper "start". They depress the brake pedal to the floor, hold it there and they say "stop". You close the bleed nipple and say "release". continue until you don't see air bubbles in the fluid. Periodically check the reservoir so it does not run low. Next, do the inner bleed nipple. Follow the same proceedure with each wheel. It should take you 1/2 hour for the fronts only or an hour for the whole car. Have fun.

Are you bleeding or flushing your brakes? If the fluid in the resevoir changed color, I assume you want a complete flush to clean out the old fluid? I'd think the old pump / stop / release method will take quite a while to flush the whole system. By the way, how much fluid do you use for a complete flush? 2 quarts?

Courtesy of 02 Carrera from when I bleed my brakes. "The reason for this is that the brake systems uses independant braking circuits with electromagentic valves. When you actuate the pedal, the valves close and the additional fluid returns through the return flow for pressure reduction rather than flow back through the valves. This is the reason why you are not recommended to use the push/pedal method since you can introduce air into the lines through the return path and damage the brake system bleeding it through this method."

Porsche actually recommends that you use the pedal method IF you have replaced the brake master cylinder or a hydraulic unit. The reason that they warn not to use the manual method for regular bleeding is that by pushing the brake pedal to the floor with the caliper bleeder valves open you can blow out the main pressure seal inside the master cylinder. Porsche gives the same warning for the older models and there are plenty of examples of people with those models ignoring the warning and ruining their master cylinder. The price of Motive Bleeder is ~$40USD so there is really no reason not to use a pressure bleeder. It really makes bleeding the clutch and the brakes a pretty simple job and it makes it possible to bleed the ABD locks with a PST2 or PiWiS (and now Durametric?)

Jason, thanks for giving Scott the correct advice. He is a nice guy and I would have felt terrible if he followed my advice and damaged his master cylinder. I guess I got lucky. Your expertise is greatly appreciated.

Mark, I think the trick is not to push the pedal all the way to the floor, if you only go half way you shouldn't have any problems. I'm curious to know what you didn't like about the bleeder? I have the non-black label Motive that has the screw on top that won't allow the hose to rotate freely which is a PITA but other than that I thought it made the job pretty effortless.

Jason, my wife bought mine for me at Kragen Auto Parts. She paid about $50. it does not have a brand name shown on it. The manual calls it a hand vacuum pump and brake bleeding kit. Once I pressurized it and opened the nipple on the caliper it began sucking flluid out. It never stopped showing air bubbles in the system. It started leaking & then spraying fluid out of the back of the hand pump after about five minutes. I finally gave up and used the old fashioned method. That worked great and took 30 minutes. The problem is either operator error or the pump is a POS.

www.pelicanparts.com has both the motive bleeder, ate gold and ate blue.

Sounds like you were using a vacuum bleeder that hooks up directly to the caliper. CRAP Big difference from a power bleeder that hooks up to the fluid reservoir.

This is not true. You are supposed to bleed the master cylinder at a tap below is and not all the way through the lines when replacing it. This is not a pedal bleed procedure. you can do it with a vacuum bleeder though. Vacuum bleeder is cr*p for regular brake bleedings because it only usees a couple of inches of vacuum. Our brake systems are supposed to be bled at high pressure: 1.5 bars per the Porsche service manual (about 23 psi). A power brake bleeder is only about $50 (Euro version) and makes the job extremely easy. If you read the instructions for the power brake bleeder, our pressure range is higher than the typical 15-20 psi that is recommended for most applications. I normally set the pressure at 25 psi and increase it back to 25 psi once it drops to 20 psi. I get a perfect bleeding every time. It takes about 15 minutes to bleed all 4 if I have my 5-spoke Carrera street wheels on the car.

[Image-only post; no author-written text. Original image references:] https://members.rennlist.com/jandreas/996-BrakeBleedWarning.gif

OK, you guys convinced me, I'm gonna order a Motive bleeder. My wife is getting tired of helping me bleed the brakes anyway.

Vacuum bleeder's work fine on the 996. If they show air bubbles, it's just leakage at the nipple (through the threads usually), but it's still doing the job.

Just flushed my brakes this afternoon. Motive works great. Vacuum bleeder works great to empty the master cylinder and catch the bleed off since it has all the hoses. Personally, don't think it's worth much more than that. Used Super Blue. Very easy to see the change.