Grrr "modern" cars and brake flush question
#1
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I changed the front pads on 997.2 2S this morning and decided to flush the fluid also since it had been in the lines since 2009.
Flush seemed to go fine, using motive power bleeder as pressure source and doing RR / LR / RF / LF calipers.
I used about 1 1/2 quarts of fluid.
I've done this successfully dozens of times on "older" cars.
BUT
Pedal is now very soft, as in it takes an extra 1" to 1 1/2" of travel before brakes actuate.
A couple of friends tell me that likely cause = need to have a Pcar "tester" attached so as to cycle ABS pump and then bleed out of RF caliper.
Anybody know if this tracks with your experience?
If so, any alternatives to going to indy shop that has the magic tester?
thanks
Craig
Flush seemed to go fine, using motive power bleeder as pressure source and doing RR / LR / RF / LF calipers.
I used about 1 1/2 quarts of fluid.
I've done this successfully dozens of times on "older" cars.
BUT
Pedal is now very soft, as in it takes an extra 1" to 1 1/2" of travel before brakes actuate.
A couple of friends tell me that likely cause = need to have a Pcar "tester" attached so as to cycle ABS pump and then bleed out of RF caliper.
Anybody know if this tracks with your experience?
If so, any alternatives to going to indy shop that has the magic tester?
thanks
Craig
#2
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I've used the motive power bleeder on several Porsches and never had a problem with a soft pedal. You have somehow gotten air into you system. All I can say is bleed and try again. I've never had to pulse the ABS unit.
Have you used the Motive before successfully or is this your first time?
Have you used the Motive before successfully or is this your first time?
#4
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Do the newer calipers have inner and outer nipples or just the outer? On my old 928 I realized that both inner and outer nipples needed bleeding to get all the air out and a firm pedal. Anyone know?
#5
Race Director
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I use the Motive device to flush and or bleed on my 2012...never an issue. Sounds like you messed up and got air in the lines. Go do a through bleed again started with the passenger rear outside zero fittings 1st then to the drivers rear, passenger front and finish with drivers front. Use a whole bottle.
#6
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I've used the motive power bleeder on several Porsches and never had a problem with a soft pedal. You have somehow gotten air into you system. All I can say is bleed and try again. I've never had to pulse the ABS unit.
Have you used the Motive before successfully or is this your first time?
Have you used the Motive before successfully or is this your first time?
"I've done this successfully dozens of times on "older" cars."
I use the Motive device to flush and or bleed on my 2012...never an issue. Sounds like you messed up and got air in the lines. Go do a through bleed again started with the passenger rear outside zero fittings 1st then to the drivers rear, passenger front and finish with drivers front. Use a whole bottle.
i suppose it's possible i screwed something up, but I also did a complete "reflush" as you suggest when i initally noticed the additional pedal travel.
no joy on reflush unfortunately.
cheers
Craig
#7
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Also using the motive bleeder with great results. Not much different between my 05 911 and my 86 BMW e30.
If you've got a lot of air in the system, I've had good luck using a good old foot bleed. Usually, the foot method is best when you have a brand new system you've installed.
If you've got a lot of air in the system, I've had good luck using a good old foot bleed. Usually, the foot method is best when you have a brand new system you've installed.
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#9
Drifting
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Do you have a durametric tool... that will allow you to pulse the ABS if you suspect air in the ABS. FWIW, I've yet to pulse my ABS even though I have a DM tool and have done 4 brake flushes over the past 2.5 yes.
Last edited by USMC_DS1; 11-01-2013 at 03:34 PM.
#11
Race Director
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do the brake work and feel proper after the 1inch of softness?
Is it possible that there was air in the System originally and that the flush pushed it out giving you the "soft" sensation?
Is it possible that there was air in the System originally and that the flush pushed it out giving you the "soft" sensation?
#13
Burning Brakes
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15 works fine, maybe takes a little longer but I figure you should not rush brake work.
#15
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I use about 20. I usually have to pump it up a few times through the process so it drops as I flush. The real danger is not that you're going to run the system but that you're pop the reservoir off the master cylinder which would be a mess. the reservoir never sees pressure in normal use.