Car Analogy

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!

B serious

Wedging the pedal doesn't actually work, IMO. It only helps with pedal feel temporarily, if you've got a *slightly* spongy pedal. Even then...it works mostly on the placebo effect. I have a few loose theories as to why this "works", and none of them have to do with air in the system.

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.

B serious

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.

Billman250

I assure you the method is proven, but must be done properly. I have done it/and or witnessed it successfully near 100 times in the industry over the last 30 years.

It was taught to me by an 83 year old truck shop owner, over 25 years ago.

B serious

I've tried it (clinically).
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.

VapeurRacing

You need to engage the ABS, if you have the tool it's easy. If you don't we would be able to help you.

The ABS most likely has air and needs to be engaged several times until the air comes out.

HawkeyeGeoff

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.

Holeshot121

Yep. I never heard that until I had my issues and started researching more. I seem to learn a lot of lessons the hard way...

Yes, I am very diligent about properly lubing all the brake components.

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?

B serious

They use a Nissin housing with mystery meat seals.

I've never had luck on any Honda with parts store parts. BUT see how far it takes you. Don't fall victim to my defeatism.