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      02-11-2016, 02:12 PM   #1
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Exclamation Spongey Brake Pedal - Post fluid flush

Had full brake fluid flush done yesterday - 4 bottles of .500 Motul 600

Upon initially getting car back I noticed an immediate spongey pedal feel. Drove car home (about 20 miles), parked. Couple hours later got in the car, drove roughly another 20 miles, and pedal feel seems to be returning to normal. Will report back, but any insight?
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      02-11-2016, 08:26 PM   #2
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Quote:
Originally Posted by Exclusivs View Post
Had full brake fluid flush done yesterday - 4 bottles of .500 Motul 600

Upon initially getting car back I noticed an immediate spongey pedal feel. Drove car home (about 20 miles), parked. Couple hours later got in the car, drove roughly another 20 miles, and pedal feel seems to be returning to normal. Will report back, but any insight?
Did you do the flush yourself? You made sure no air/moisture (water? don't think its possible) was introduced into the system then should be fine. I always did mine myself and never had spongey brakes post flushing. Also, was brand new fluid used? Old brake fluid could absorb moisture over time and is not good to use. Always new sealed fresh fluids!

As long as the brakes are fine now, you shouldnt worry too much. For peace of mind you can bleed the brakes again to make sure all the air and fluid is good.(should take 1-2 500ml bottles).
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      02-11-2016, 08:46 PM   #3
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Originally Posted by kaede View Post
Did you do the flush yourself? You made sure no air/moisture (water? don't think its possible) was introduced into the system then should be fine. I always did mine myself and never had spongey brakes post flushing. Also, was brand new fluid used? Old brake fluid could absorb moisture over time and is not good to use. Always new sealed fresh fluids!

As long as the brakes are fine now, you shouldnt worry too much. For peace of mind you can bleed the brakes again to make sure all the air and fluid is good.(should take 1-2 500ml bottles).

I did not flush myself - local reputable indie shop did so there is no way for me to verify if air was introduced. Brand new fluid used - I'm keeping eyes on how they feel seem to be regaining normality - but yesterday after initial flush I've never had the brake pedal reach as low as it did.

Am going to call shop tomorrow and report ...
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      02-11-2016, 10:05 PM   #4
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Couple of possibilities. If they didn't use the computer to bleed the ABS/DCT, air could've gotten into the ABS unit, causing the sponginess. Fix - Do a full bleed using the computer to cycle the ABS unit.

Second, if they pressed the brake pedal too far down (aka all the way to the floor) during the fluid flush, they could actually have damaged the master brake cylinder. You're only supposed to pump the pedal 2/3 of the way, not all the way to the floor. Fix - Replace MBC.

Good luck.

Last edited by Redd; 02-11-2016 at 10:12 PM.
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      02-12-2016, 10:44 AM   #5
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Quote:
Originally Posted by Redd View Post
Couple of possibilities. If they didn't use the computer to bleed the ABS/DCT, air could've gotten into the ABS unit, causing the sponginess. Fix - Do a full bleed using the computer to cycle the ABS unit.

Second, if they pressed the brake pedal too far down (aka all the way to the floor) during the fluid flush, they could actually have damaged the master brake cylinder. You're only supposed to pump the pedal 2/3 of the way, not all the way to the floor. Fix - Replace MBC.

Good luck.
Don't believe a computer was used - as it was not dealer but an INDIE shop.
As noted - pedal feel has seemed to return to normal, certainly not as spongey as initial drive. Just curious if this is normal
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      02-12-2016, 08:44 PM   #6
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Could be just the air cycling out. I'd do a bit of self bleed just to see if there is any air at the end of the lines.
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      02-13-2016, 11:57 AM   #7
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Quote:
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Could be just the air cycling out. I'd do a bit of self bleed just to see if there is any air at the end of the lines.
As in is always going to remain? Unless fully flushed again ?
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      02-13-2016, 04:15 PM   #8
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I have the same issue and I think it's the MBC that needs to be replaced
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      02-13-2016, 09:28 PM   #9
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Quote:
Originally Posted by italyix View Post
I have the same issue and I think it's the MBC that needs to be replaced
Things have seemed to return to normal feel

Haven not experienced a soft pedal since ... wonder what the cause was
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