About two weeks ago, I was sitting at a light and I noticed something funny. With my foot on the brake, the pedal moved slightly. I took note of this, and it only happened when I had I was holding the brake.

I then stored my car for a about 3 days, as its not a daily driver.
Had to pick up my mom one evening, and decided to take the TL. As I was coming out of my neighborhood, sitting at a light my brake pedal went all the way to the floor. I drove it like that to another light, and had to turn around. I knew I had air in the brake lines.


While it sits, I like to play Frankenstein and operate on it quite often. As for the last time I opened the master cylinder, maybe I forgot to tighten the cap. Or maybe installed the rubber seal wrong.


When I got back home from picking up my mom, I took a look at the master cylinder. The cap was really hard to un-screw. When I did get it off, the rubber seal jumped out a little. I tried to put it back in place, but no matter how hard I tried I could not get it to seat properly. Somehow the pressure inside the master cylinder fucked this rubber seal up. It was enlarged.
I let it sit, as I have no need for the car.

On friday the 11th I finally got my lazy ass to search the part # to order it.
It's called a diaphragm; part#46669S5A003.
Called local dealers and they did not have in stock.


I ordered it on Friday before noon, at oemacuraparts.com. I chose them because they're in Arizona as opposed to delray acura in florida. I wanted the seal as fast as I could get it!
What the heck, since I'm ordering a replacement part, might as well buy a mod too. I bought Stainless steel lines and MOTUL 5.1 brake fluid. Also, before noon on friday.

I should have known, they weren't going to ship out till monday.

Today, I received the diaphragm.
You can see the difference.


I havent installed it yet, as I'm still waiting for Excelerate's package.
I think it was bearcat who turned me on to this TSB.
http://techinfo.honda.com/Rjanisis/pubs/SB/B07-041.PDF

Which list the symptom; when brakes applied the pedal is lower and feels softer than normal.
it is caused by air entering the the brake system from the VSA Modulator-control unit.

Will call around local dealerships to take care of that.
but for now I'm waiting for my fluid and brake lines.

 

Kind of odd that the diaphragm swelled that much. I'd be interested in knowing why that might happen.

 

To me it looks as though it has been damaged by a petroleum product, hence the swelling. The new cap seal isn't going to correct the pedal going to the floor.

 

The symptom you describe is usually a master cylinder gone bad, if the rest of the hydraulic system checks out ok. When this happens the master is replaced with a new unit.

I've replaced a few Honda masters gone bad. Even happened on my old '90 Integra sedan. From the past, I've noticed its common in relation to the pedal dropping with roughly a 7-10 year old Honda.

The part you have looks like it is much smaller, maybe you ordered the seal for the clutch master cylinder by mistake, since you have a 6MT.

 

Brake fluid has only been in the reservoir. the new seal was to replace the old seal. I believe its just air in the lines, and would just need to bleed. as soon as I get those SS lines.

This is the cap and seal. it says up side.


this is the cap and seal correctly installed.


it fits.

 

I agree with Turbonut, it's some sort of contamination. Are you the original owner of the car?

It honestly looks like someone installed a DOT 5 fluid in there judging by the swollen rubber. At a minimum I would do an extremely thorough flush.

 

I've got all the brake lines off. what else or how else can I flush?
no not the original owner.

 

I think the biggie would be the modulator. If you can cycle it while doing the bleed, definitely do it. If you have to cycle it by actually driving and hitting ABS, make sure to do another flush on the system after engaging ABS a few times.

I don't know if there's any rubber on the piston in the MC but if so, silicone fluid would explain everything. Not sure what the rubber will do once you introduce the correct fluid. I would be very cautious for a while. You may even soak the old rubber seal you replaced in the new fluid for a few days and see what it does.

 

if there is rubber in the MC, it most likely swelled as well, correct?
If flushing out doesnt correct my problem, I'll try replacing the MC.

I hope the Modulator is okay.

 

That was my concern, this could turn into a real safety issue. I've never looked at a TL MC so I have no idea if there's rubber in the MC or in the modulator but I would be there's rubber in that system somewhere.

Are you the original owner or is there a chance that it could have silicone fluid in there? The really bad thing is that if it leaked past the MC into the booster and sucked into your engine, it does very bad things to engine internals when burned, basically turns into "sand". It might be worth it to pull the vacuum line just to check. I'm sure you would have noticed issues if it were leaking, but still it would hurt to check.

I don't know how to test for silicone but I'm sure there's a simple test you can do.

 

No, I'm not the original owner.

Should I just replace the Master Cylinder to be safe?
Jordan wanna help?

 

Not sure. Maybe a parts diagram or one of the techs on here could tell you if it contains rubber parts. Do you still have the swollen lid to "test"?

 

Sure, no prob man.

Replacing the MC would be a good idea. That's probably why the pedal was dropping.

All you can do is hope for the best at this point, as far as the ABS unit. It is a possibility you just had a defective seal from the seal mfg, AND a bad MC.

Do you have the factory manual? I'll set it up so you can DL it, or I can put it on a thumb drive. We can check if there is any instructions on how to bleed the ABS unit.

 

^^^ Rubber doesn't just swell like that for no reason.

 

I do have the service manual.

 

I agree, that's not what I'm trying to say. It is possible the seal was somehow compromised when originally manufactured or handled in the past. I agree, the seal is most likely swollen due to fluid contamination. It's sure swollen quite a bit. The manual even states to check for a bulging seal, when performing a brake inspection & test.

I looked quickly looked through the manual. Didn't see anything on bleeding the ABS modulator. Just a standard bleeding procedure.

 

I have the strut bar off. I just ordered the MC.
I'm praying to God that the scenario I hate cars explained does not come true.

 

I hope not too. Just had to throw it out there since it's brakes we're talking about.

 

What did the fluid look like when you first did your brakes?

Was the level near the low mark on the reservoir?

 

if I check the brake booster vacuum lines and see nothing, then most likely I'll be fine correct?

 

Should be. Chances are you would have a hard/inconsistent brake pedal if it was leaking. Very small chance of this happening.

 

the opposite.
When I compressed the piston, the fluid went over the MAX line.

 

I just found this, it might help a little. I guess I'm still assuming it was the wrong brake fluid. Could still be petroleum contamination.

http://www.adlersantiqueautos.com/articles/brake1.html

 

GAWD IHC,... is there anything you don't know?

 

Does silicone sludge? I have found evidence of sludging in the MC. Which leads me to believe that it is petroleum contamination.

My course of action is to replace the MC, put on SS lines, fill with 5.1 brake fluid. bleed. then drive and engage ABS, drain fluid. refill fluid and rebleed.

 

Don't forget, your 6MT with the Brembos has 2 bleeders on each front caliper, outside first, then inside.

 

Thanks.

I hope the contaminated fluid is flushed out and I will have no ill effects from this.

 

Might need more than a quart....

 

Yes, if there is any sludge from deterioration, adding Dot 5 will increase that sludge area. Also, if the previous owner changed to Dot 5 and flushed the system first, or just decided to to do a general flush out of old fluid and used the wrong fluid for the flush, the rubber products will swell.
Hope it isn't Dot 5 as you'll never get it all out of the system.

 

Thank you, gentlemen.

 

Update.


I performed the brake fluid test that Matt suggested on the black rubber seal. It's been soaking for about a week.







I still dont have all the parts in due to a parts website. Hopefully I can resolve something with them pretty soon, as it sucks not knowing if my vehicle will be okay.

 

My vehicle is up and running with no ill effects.

 

Good deal! How much fluid did you use to flush the system?

 

I had ordered the stainless steel lines the same time I ordered the diaphragm.
While waiting for those, (Excelerate had shipped them out a couple days late, no biggie) I took off the old lines.


Passenger Side Brake Line.


Driver side Brake Line REMOVED.


Driver side removed.


Rear Left.

Here is the comparison shot.


I then posted on here, and found out that the MC was contaminated. I had ordered one, and in the mean time took off the old Master Cylinder.

Only to realize that the brake line closest to the firewall had seized.
Even with a flare nut wrench I could not take off the 12mm bolt.

I then decided to replace that whole brake line, which connects to the VSA Modulator.

My car sat like this for weeks, as there were MOAR mess ups with shipping...



My master cylinder DID not come in for at least a week and half when I prompted for 2 day shipping.
Instead of ordering online, I thought I would have to trust the dealer to order the brake line that I needed.

The online price for the brake line was 10 dollars, but at the dealer they insisted it was 40. I paid and then patiently waited for the line and the MC.
After at least another week, I then had all my parts to start.

I woke up early saturday morning and got to work. Removed the MC with the brake line attached. I then fished in my new brake line only to find the brake line bolts were TOO BIG!


the new line uses a 14mm while the old line(and the rest of the other lines) use a 12mm.
The brake line attaches to the VSA modulator and hugs the Firewall all the way to the MC.

I hightailed it to a junkyard with my boy(forum member Bada$$vtec)
found a nice speciman and bought it.


Big Thanks to BADASSVTEC as he helped me a lot.
Emmanuel had came back around 10pm to help me bleed the brakes.
Since, I had the car up on jack stands with the lines removed, all the fluid drained out. There was still some left inside the calipers. that old fluid came out when I bled the brakes.


Well, I had planned to fill it with regular DOT 3 fluid as per matt's instructions of activating ABS a couple of times. to completely fill the reservoir with correctly bleeding the system took 1 and half bottles of Prestone. Each bottle is 12 FL OZ.

I took the car out and did some HIGH speed stops to activate ABS.

This weekend, will drain and refill with MOTUL 5.1 Brake fluid.

 

What did you use to remove the clips on the brake lines?