"Spongy brake pedal first 20%" need to bleed Brake Master Cylinder?
#1
Newbie
Thread Starter
iTrader: (1)
Join Date: Dec 2005
Location: CT
Posts: 73
Likes: 0
Received 0 Likes
on
0 Posts
"Spongy brake pedal first 20%" need to bleed Brake Master Cylinder?
I've wondered this for a long time now, and I've searched everywhere. Is it possible to bleed the brake master cylinder on the evo? The reason I wonder this is after bleeding the brake lines on multiple occasions multiple times i still end up with a "spongy" brake pedal for the first 20% of the pedal. Not sure if this is caused by cold ferodo ds2500's... or just because i was "bedding" them in. it seems to firm up as you increase the pressure on the brake pedal past 20%...
The closest thing i've found about bleeding the master cylinder is this, which seems to require us to disconnect the lines... this seems counter-productive to me:
https://www.evolutionm.net/forums/04...-cylinder.html
any insight out there?
The closest thing i've found about bleeding the master cylinder is this, which seems to require us to disconnect the lines... this seems counter-productive to me:
https://www.evolutionm.net/forums/04...-cylinder.html
any insight out there?
#3
Newbie
Join Date: May 2009
Location: Killeen, Tx via Fayetteville, NC via Worthington, OH
Posts: 76
Likes: 0
Received 0 Likes
on
0 Posts
Most brake issues can be fixed with a proper bedding session.
For some great info, check out this link. He has forgotten more about brakes than we have used them.
http://www.zeckhausen.com/technical.htm
For some great info, check out this link. He has forgotten more about brakes than we have used them.
http://www.zeckhausen.com/technical.htm
#4
Newbie
Thread Starter
iTrader: (1)
Join Date: Dec 2005
Location: CT
Posts: 73
Likes: 0
Received 0 Likes
on
0 Posts
first bleeding session was done with ATE blue. that's when I first noticed there was a bit of "travel"/spongyness when the brake pedal is depressed from 0-20%. Just flushed with motul rbf660 this past weekend. After bleeding them and bedding them in, I felt that the travel had actually increased slightly compared to when i flushed/bled with ATE blue. (about 9 months ago)
Is this a symptom of air in the lines? the pedal doesn't drop to the floor or anything, in fact it is firm after the 0-20% of travel/"spongyness".
Is this a symptom of air in the lines? the pedal doesn't drop to the floor or anything, in fact it is firm after the 0-20% of travel/"spongyness".
#6
Evolved Member
iTrader: (72)
How did you go about with the bleeding process? Did you do the bleeding sequence correctly? and doing both bleeder valves on each caliper? If you did the two man method, did the pedal pumper ever let go of the pedal while a valve was opened? Did you us a line to lead the fluid out, and made sure there were no bubbles inside the line? Was each caliper bled fully with no signs of the old fluid? Did to tightened the bleeder valve just enough? These are all simple questions, and may make you sound stupid, but people forget all the time. I would by new fluids and flush the entire system again. Before doing so, make sure all of the brakes lines are tight. I did ATE 4 moths ago, doing braided lines at the same time and have had zero issues. Good Luck.
Trending Topics
#8
Newbie
Thread Starter
iTrader: (1)
Join Date: Dec 2005
Location: CT
Posts: 73
Likes: 0
Received 0 Likes
on
0 Posts
re:
basically followed this guide to bleed: http://www.joe250.com/cars/evo8/brak...ebleeding.html. they were bled in the correct order. both bleeders per caliper. two-man bleeding process, i was pumping the brakes - didn't let go until the valve was tightned. we used a line out every time we bled. there was a bunch of air bleeding the front two brakes from the previous flush... that might explain the spongy feeling from the ATE flush...
will try to bleed them again and see if there is any difference.... so i take it there's no reason to bleed the brake master cylinder then?
will try to bleed them again and see if there is any difference.... so i take it there's no reason to bleed the brake master cylinder then?