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Question on Brake Bleeding & Photos of My New Brakes - Girodisc
I would like to know how you guys bleed your brakes. I changed rotors & pads this weekend and I bled the brakes (the way I know how) using a Motive Power Bleeder. Although I was able to flush the system, I did manage to get bubbles in the lines and after a through flushing, the air bubbles were all gone but my pedal is a tiny bit mushy.
The problem, that I see, is that I use the power bleeder to pressurize the system but I don't put brake fluid into the power bleeder (a friend at work told me I should be butting the fluid into the pressure bleeder tank). I just use it to push the fluid thru. However, I believe the master cylinder was a little smaller than I thought and I accidently ran it out of fluid on the initial flushing. I kept it topped off going forward and as I opened the bleeder valve on the right rear wheel, I saw quite a few bubbles. After some time, the fluid was clear and no bubbles.
I bled in the following order; Right rear, left rear, front right, left right. I bled the system twice.
After all was done, I drove the car and bedded the pads but the pedal is a bit spongy and I believe there is still some air in the system. Am I supposed to push on the brake pedal at any time during bleeding (using pressure bleeder)? I'm going to re-bleed the brakes tonight and I am asking for any tips from the experts here.
BTW: Original Front Rotors were 18.4lbs ea, Girodiscs were 18.4 ea but 1" larger in diameter. Original rear disks were 15.0 lbs ea and the Girodiscs were 17.5 ea but were 1" larger in diameter. Because of the larger rotors, Girodisc supplys new mounting bolts with spacers and you can see the large space between the hub and the caliper - stock only has about a 1/4" gap.
Thanks and below are a couple of pics of my handy work:
Think you have to do it again if the reservoir got low during the process. Sorry.
I put all the fluid (liter) into the Motive and let it pump into the reservoir during the bleeding (good design, actually). I empty the reservoir beforehand with a syringe in order to accelerate the entry of the "fresh" fluid from the bleeder into the system (why push "old" fluid from the reservoir into the system? - Ditch it). When I pump up the Motive, fluid flows freely into the reservoir and level never gets too low.
I do not touch the pedal during the bleeding process. Perhaps only afterward or to press pistons / pads back into extended positions against the rotors (if changed during the same process, else, no need to).
So...
Empty extra fluid in reservoir.
Put fresh fluid into Motive.
Pump it up to 15 or 20 psi (I used 15 with no issues last time).
Bleed inner and outers, sequence by your preference (me... RR, LR, RF, LF, clutch slave).
Check the pressure and re-pump as needed between each caliper stop.
Slowly release Motive container cap to releive pressure.
Disconnect Motive from reseroir and wipe up extra brake fluid.
Adjust reservoir level to your liking, plan to recheck after next active drive.
I usually stuff a few rags beforehand around the reservoir to collect any seepage or overflow. Not sure you can ever avoid a little bit of mess there.
Thanks for the tips. You mention "clutch slave"....where is this located and does it have a bleeder valve similar to the calipers? I've never bled a system where the clutch shared the master cylinder probably because my newest car I own (other than the Cayman) is my '74 911 which has a cable operated clutch.
I would echo the above, except that I do not put fluid into the Motive bleeder; instead I just refill the master cylinder tank a couple times during the bleeding process. This way I don’t have to clean the Motive when I’m done!
The bleeder valve for the clutch is on top of the transmission and a PITA to reach. I bleed it every year or two, but not during every brake bleed, which can occur several times a year.
I put fluid into the motive pump, that way you never run the risk of air in the system as far as I know. I bleed every six months if I am going to be taking it on a track like COTA that requires it.
If you think you may have gotten air into the MC, there is also a chance it migrated into the ABS. Before bleeding again, take it out and force the brakes into ABS a few times. Then re-bleed the entire system, maybe twice. Fluid in the Motive or not is purely a matter of preference. I do a dry flush, using the Motive as a pump, but watch the level in the reservoir carefully.
If you think you may have gotten air into the MC, there is also a chance it migrated into the ABS. Before bleeding again, take it out and force the brakes into ABS a few times. Then re-bleed the entire system, maybe twice. Fluid in the Motive or not is purely a matter of preference. I do a dry flush, using the Motive as a pump, but watch the level in the reservoir carefully.
FWIW, I'm a die-hard fan of "put the fluid into the Motive" to bleed the system. Been doing it for years on all my Porsches. Constant pressurized feed, no risk grabbing air, fast... Heck, my kids would do it on my 944 when they were small. That said, whatever works best for you...
This write-up on the Boxster / Cayman clutch slave was the ticket for me.
Thanks for the link to the clutch slave cylinder. I'm pretty positive I would not find that hidden bleed valve without the link/
Thant said, I am going to do a second flush/bleed tonight and I will put the fluid into the motive container. It's easier that way when I'm by myself on this project and it will only take a little while to clean it out when done. I previously didn't like doing this because I used to use the super blue brake fluid and that stained the motive container. But with some acetone, it finally came clean.
Timely thread as will be doing brake service soon. At last oil service I was advised that pads would needed in the near future so bought the neccesarys in anticipation. The pad service light came on yesterday so that’s a sign the time has come. So here’s the question. How is the system reset after the pad service. It is a 06Boxster.
EDIT.
finally did the work, front rotors and pads all around. I used the motive power booster and that and a lift makes it an easy job. I did have a persistence issue with air though. Many many bubbles so I pushed a lot of fluid through. Darkest thing the air wasn’t in the lines. It was drawing from the poor connection of the hose on the bleeder. The hose had to much angle and when I straightened the hose the bubbles stopped. Bonus is there is very clean fluid in the system and yes all the lights are reset.
Using the Motive bleeder without brake fluid in the container is fine. However, in this case, when you let the master cylinder ran dry you introduced air in the system. Bear in mind that once you have air in the system, it will inevitably have gotten into the ABS module. The best way to get that air out of the ABS system is to use the Durametric tool. There is a function to recycle the ABS solenoids and this will purge the air as well as refresh the fluid within the ABS chambers. Thereafter you can bleed the brakes again to get the air out from the lines.
Timely thread as will be doing brake service soon. At last oil service I was advised that pads would needed in the near future so bought the neccesarys in anticipation. The pad service light came on yesterday so that’s a sign the time has come. So here’s the question. How is the system reset after the pad service. It is a 06Boxster.
In my '05 Boxster S, the pad light recycles on start-up. If no contact signal from the pad sensor, no light. As soon as pad sensor makes signal, light until next start up. Mine would go out and "reactivate" once the brakes were applied sufficiently to activate the sensor in the pad. I would suspect the '06 behaves the same. If so, replacing pads / sensors will clear the light.
Not sure I understand why folks would want to use the Motive pressure bleeder dry... Maybe I'm missing it?
You need to move about a liter of fresh fluid to flush the system (+/-), the reservoir does not hold that liter of fresh fluid, disengaging the Motive to now add part of a liter depressurizes the system, and one risks getting brake fluid all over with each disconnect/fill/reconnect cycle. I think i's a brilliant tool when used as designed.
The best way to get that air out of the ABS system is to use the Durametric tool. There is a function to recycle the ABS solenoids and this will purge the air as well as refresh the fluid within the ABS chambers. Thereafter you can bleed the brakes again to get the air out from the lines.
Good Advice! I have a Durametric tool so this will be a good reason to use it.
Originally Posted by Dave in Chicago
Not sure I understand why folks would want to use the Motive pressure bleeder dry... Maybe I'm missing it?Dave
I already used the Motive dry and look what happened - I have some air in the system. This probably would not have happened if I topped off the reservoir more frequently. My only reason for not putting the brake fluid into the Motive was to save time on cleaning. Now, I'm going to spend time re-bleeding the brakes this weekend. I'm definitely going to put the brake fluid into the Motive and I will spend an extra 15 min cleaning it when I'm done.
Not sure I understand why folks would want to use the Motive pressure bleeder dry... Maybe I'm missing it?
You need to move about a liter of fresh fluid to flush the system (+/-), the reservoir does not hold that liter of fresh fluid, disengaging the Motive to now add part of a liter depressurizes the system, and one risks getting brake fluid all over with each disconnect/fill/reconnect cycle. I think i's a brilliant tool when used as designed.
Not trying to flame, but I'm just not getting it. My 2 cents. Then again, your mileage may vary.
Cheers!
Dave
Completely agree - I thought that was the whole point that it could pressurize with fluid transfer. Never dawned on me to use it for pressurizing only.
Question though - I use it about every 6 months - is there any problem with storing extra fresh fluid it in for that long?
08-27-2018, 06:39 PM
Question on Brake Bleeding & Photos of My New Brakes - Girodisc
