Frequency of Brake Bleeding

I was curious how often most of you all bleed your brakes and how many of you do it yourself versus a local shop? What is typical pricing at local Porsche shops or dealers? Do you take your own fluid if you want anything different than the standard? DO you need a full flush to change type or can it be done over several bleeds? I have been to a few autocrosses and 1 DE in the past few months. I have 3600 miles and plan to do at least 10 more events this year. Thanks

Here is a recent discussion that might be of interest: http://www.planet-9.com/cayman-tech/15362-questions-about-bleeding-brakes.html

Thanks for the thread santa fe. I have read that one before and others on the forum also. I was hoping to get more specific info about how often. . .and other options than "do it yourself". Perhaps its best to "do it yourself" and i can be convinced, but I don’t have much space for more equipment. I am also interested in knowing how often most members bleed and flush. some other pca members mentioned bleeding every DE. At the shop I got teched at, the said every 2 years. big difference in the info. if i had to do it every time, I would be more convinced of doing it myself because i guess it would get expensive over time. I have also read the threads on recommended brands and boiling points. . .etc. . .that’s why I also wonder if you get it done at the shop and want a special fluid is it best to bring your own. I am also curious how often, for those who use the cayman off road, change the pads also?

Hard questions to give specific answers to. I bleed and flush/change fluid whenever it will make me feel more comfortable, maybe more frequently than necessary. I think I flushed/changed twice during last season and just bled maybe twice. Brakes worked fine for 4 track events and about 10 autocrosses. Some bleed before every track event, and flush/change every 3 months or so. A Porsche Certified Master Tech at the dealers told me just the other day that new ATE brake fluid should last me all season, but I've never gone that long on the same fill. Normally (no tracking) they change fluid every two years. Change pads at least when they get close to minimum recommended thickness. That thickness is frequently in the printed instructions, and is usually somewhere around 1/4 inch. I want at least 5/16 because the pad mass also works as a heat sink, helping to dissipate a little of the heat. I use PFC 90 compound for track; OEM pads otherwise.

For the DIY's, do you also bleed the clutch every time you do the brakes?

If you brake real hard and real often, thing track usage, then your brake fluid may get to boil. If that happens, then the liquid boiling creates a gas, and that gas doesn't fully transform back to liquid. So, bleeding the brakes removes that gas, making the pedal firm again. Some folks bleed their brakes after every session. And then brake fluid is hygroscopic, meaning that it absorbs water. Water boils faster than brake fluid, so that isn't good to have in the system as it will make your car not stop very well. And the water content will also cause corrosion, if left too long in the system. Most manufacturers recommend replacing all brake fluid every two years. I use a fluid evacuation system, available from Car Care, Detail Supplies, Garage Organization, Car Accessories - Griot's Garage [phone removed] for one. It is a one person operation and it doesn't take very long at all. The one they sell comes with a plastic reservoir bottle that you fill with brake fluid and then place it in the opening to the car reservoir. Then you travel from bleeder to bleeder "pulling" the new fuid into the system, via vacuum. For the Cayman, I am scheduling for the 2-year service, where Porsche will perform the fluid replacement the first time.

fmarshall. . .thanks for the info. . .do you own the fluid extractor that hooks up to a compressor or the one you hand pump? Its interesting that this one sucks out fluid vs the motive bleeders that forces the fluid through. Seems like a good system because the apparatus and the reservoir are combined- less parts. Are there any drawbacks to suctioning?

I bleed my brakes before every track weekend. I do not bleed for autocross events as they simply don't put much heat into the brake system in comparison to a track day. It's done at home with a Motive Power Bleeder bottle and a home made catch reservoir. I only bleed the clutch once in a great while. As a DE instructor for BMW CCA and PCA, I never want to see a student bend a car, or even lose part of their day at the track because they failed to bleed their brakes. It's a simple procedure to learn to do oneself. Get a knowledgeable track junkie to help you do it the first time if you are concerned. Then you'll be confident to do it yourself in the future. While you are in there doing the bleed job, you get a change to thoroughly inspect the pads & rotors as well. The organizations I run with each have a maximum time period between when a entrant's brakes were last bled and the date of the DE. I consider anything over 2 months too long. A novice can get buy with fewer bleeds - maybe every other weekend. But once you learn to brake with confidence (hard and late), just commit yourself to doing it before every event. Why mess with the most critical safety feature of your vehicle - especially your precious Cayman ?!?

I have the hand pump model. It works great. No drawbacks noted. Although, I would keep a spare o-ring om hand. After a year of storage, and after emptying the reservoir, the seal wouldn't seat (swollen), so I had to get a new o-ring from the local parts store. Besides brakes, I also use it to extract fluid from the supercharger on my Avanti, making a fluid change there really simple.

I have been looking into all the options mentioned in the forum and also lots of others sites, books etc. Thanks for all the help. The fluid extractor from griots garage looks like a good option. I have a few more questions you all could help with. I called a few shops just to get an idea of how much a bleed service would cost. They said bleeding was really not a good idea. . .that once there is any air it should be flushed. This is contrary to what all the books and track enthusiasts say. Once there is air in the system, is it usually limited to the lines, therefore bleeding gets most of it out? Or is the purpose of bleeding just to get air out of the lines and some air still remains inside the cylinder? When bleeding, I have read here and other sources that some brake fluids can be mixed with others, but some cannot. . .ie dot 3 and 4 are safe to mix etc. . . If I have the standard oem fluid in now and don’t want a full flush at this point, I understand I can use something like an ATE gold or the OEM fluid for a bleed? I have read all the literature on boiling points both wet and dry and understand the concepts. So far I have 1 DE on my cayman and several autocrosses. I am considering bleeding before the next DE and trying to figure it all out before then. The brakes seem fine, but all this reading on the forums and racing books has made me think my pedal has gotten a bit mushier. Is a simple bleed using ATE gold or OEM fluid my best bet at this point? Then perhaps after this year of DE’s the go for a full flush?

In my opinion this is excellent advice. Why take chances on something as important as brakes, when brake fluid isn't all that expensive? (At least if we are talking DOT4 stuff.) On every car I've owned one track session means some funny-colored brake fluid when I bleed, and I bleed until it is the light amber I want to see. For any car I track I fully flush every year. I'm not sure yet if I'll track the Cayman... I've never tracked such an expensive car.

Please help with these specifics. . .thanks

please help. . read up. . .thanks