Need help getting air out of the brake system
Normal brake usage you never press pedal to floor. So gunk builds up on mc shaft where seal never wipes that portion of shaft.
Then someone does a brake bleed, and presses pedal to floor. The gunk end of shaft gets rammed through seal, damaging it.
When you pedal bleed, don't go to floor!
Then someone does a brake bleed, and presses pedal to floor. The gunk end of shaft gets rammed through seal, damaging it.
When you pedal bleed, don't go to floor!
So wedging the brake pedal didn't do anything for me. I looked at the fluid I drained out during bleeding and saw some black specs. I picked out one relatively large piece and it felt like rubber. Starting to think I got the air out but damaged the MC during bleeding. Probably getting pieces of a seal in the fluid.
You seem like you've got massive air in the system.
Edit...it seems you found your issue.
Its true, and I always advise this...you should never push the pedal to the floor. The brake system is massively neglected by everyone. So the last portion of the MC is liable to be clogged with junk.
For future users' reference, though:
I've never had issues just bleeding out the system in conventional ways (using a 1 man bleeder) you've already described. So...unfortunately, I don't have advice than to just keep trying and make sure your method is correct.
The 2 man method should be archived. Its slow and error prone. Use the other man for good conversational company...but bleed the brakes yourself.
Also...are all your pad and caliper slides lubed properly? People neglect the pad slides a lot. Caliper slides are pretty commonly checked.
Try a reverse bleeder, perhaps. A cheap one is $60ish.
Last edited by B serious; Apr 11, 2019 at 10:06 AM.
Also, to field your future question...yes, its pretty normal for your aftermarket master cylinder to fail in a short period of time.
Pro tip for others: now is the time to buy brake fluid stocks.
Pro tip for others: now is the time to buy brake fluid stocks.
It was taught to me by an 83 year old truck shop owner, over 25 years ago.
Last edited by Billman250; Apr 11, 2019 at 01:38 PM.
In my experience, it works for the first day or so. I'll admit thaf immediately after doing this, the pedal feels great. But then it returns to normal pretty quickly. I've seen the same comment from several other users.
I don't really understand the principle behind removing air in this manner. I guess the thought process is like pressurizing a aerated liquid and then letting the "fizz" out when you release the pedal (like opening a soda)?
Its not a sound theory (IMO). You're blocking the MC ports when you push the pedal. You also pressurize and release the pressure every time you brake.
I believe all the over-night blocking does is either compress the brake pad material temporarily...or it makes the caliper piston "stick" to the pad...or it removes slop from the slides...or you're doing something temporary to the booster diaphragm. All temporary things.
I'm open to some explanation other than my understanding, however.
Last edited by B serious; Apr 11, 2019 at 02:12 PM.
I just use a power vacuum bleeder:
https://www.harborfreight.com/brake-...der-92924.html
I frequently have to bleed slaves + master cyls at work and use that + an attachment to the master res. Also use it on my car to bleed the brakes every few track days. Works great assuming the fluid is good.
https://www.harborfreight.com/brake-...der-92924.html
I frequently have to bleed slaves + master cyls at work and use that + an attachment to the master res. Also use it on my car to bleed the brakes every few track days. Works great assuming the fluid is good.
Normal brake usage you never press pedal to floor. So gunk builds up on mc shaft where seal never wipes that portion of shaft.
Then someone does a brake bleed, and presses pedal to floor. The gunk end of shaft gets rammed through seal, damaging it.
When you pedal bleed, don't go to floor!
Then someone does a brake bleed, and presses pedal to floor. The gunk end of shaft gets rammed through seal, damaging it.
When you pedal bleed, don't go to floor!
The reman MC was a Nissin unit just like the factory one, or at least the housing anyway. Do the seals wear out prematurely or what?
Thread
Thread Starter
Forum
Replies
Last Post
OneSilverS2k
S2000 Brakes and Suspension
6
Mar 22, 2011 02:51 AM














