supasixfo

iTrader: (1)

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?

chu

iTrader: (72)

You probably need new brake fluids by now! Get yourself some knowledgeable help if you've never done it before. A motive bleeder would be best for a one man job. Get a good fluid, and new pads would bring the brakes back to life!

Hioffcr

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

supasixfo

iTrader: (1)

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".

Evoryder

iTrader: (55)

Upgrade to stainless lines and she'll feel like a brick from pretty much up top. I have a motive bleeder and that thing works amazing, clutch and brakes taken care of in about 1hr

chu

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.

MrBonus

iTrader: (4)

It sounds like something was wrong with your bleeding process.

supasixfo

iTrader: (1)

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?

chu

iTrader: (72)

Did you make sure the fluid in the reservoir did not get too low to let air in the system? Its important to continue refilling the reservoir as you're bleeding.

supasixfo

iTrader: (1)

fluid was checked and refilled to max after every caliper.

chu

iTrader: (72)

Man, now I'm beat!!!

cfdfireman1

iTrader: (11)

How do the rotors look? If you try to match new pads to really worn rotors it will take some time to get a good match between them.

supasixfo

iTrader: (1)

new 2-piece slotted giro-disc rotors.

so if there's no master brake cylinder that needs to be bled, then i'm guessing there's some air in the lines somewhere that we didn't get out.... i'll try to rebleed them.

Smike

iTrader: (8)

I agree, sounds like air.

cfdfireman1

iTrader: (11)

Try to get the ABS activated a few times before you bleed them again.