Howdy all,

So as my previous problem about my brakes being soft still exists.

My setup is a 92 Civic CX with willwood 13 inch front rotors SI rear disk the whole system is stainless steel brake lines. I'm using the oem brake booster and the oem master cylinder "recently replaced with one at autozone.. the problem still exists"

so when I bleed the brakes i get very hard pedel stopped I have probably gone though at least 32-64oz of brake fluid and I do not see any bubbles. I have an adjustable proportioning valve next to my clutch for the rears.


OK so I bleed the brakes all around do the rears then the front right and then the front left, as I tighten up the last bleeder valve I have someone push the pedel and it is very hard. I drive down the street and when I stop it's like theres not enough pressure on the disks and i let off the brake pedal pump it and I stop better, let off it and pump it once more and I completely stop "each time I let off and pump it I stop better"


So previously in this post https://honda-tech.com/forums/suspension-brakes-54/92-eg-willwood-fronts-stock-disk-rear-2811785/ The rear lines exploded and have been replaced with custom built ones.

I have replaced the OEM master cylinder with a new one from autozone the problem still exists.

The brake booster is also original on my civic and it holds vacuum .. I disconnected the vac line from it and plugged the tube going to the Intake Manifold... I wouldn't recommend this I couldn't stop worth a **** !! "I knew this but I had to humor myself and try anyway"...


I have been told that stainless lines expand over time although I had someone pump the brake pedel as I felt the lines to attempt to feel them expanding.. I however do not have any leaks in my system and I don't feel any lines expanding.





Previous to all my problems the car stopped like nobody's business! and I didn't have to push the pedal down at all to get the car to slowdown.



Side note Is it possible the wheel cleaner/tire blacken-er stuff got on the pads and somehow is causing the pads not to work? "to me this sounds stupid since it seems like after about 100 feet of stopping the stuff would have heated off and disappeared..


IM OUT OF OPTIONS! not sure what the crap to do.. I'm all ears guys.

 

You MC is too small.

 

If you say its too small, what is a honda replacement for that master cylinder? that works with the EG booster?

 

I don't know without seeing your booster but you probably want to be looking at a 1" MC/BB combo.

 

Well Talked to a friend at work told me I should try the acura brake booster and master Cylinder.

The civic is 13/16ths the acura one is 15/16ths so I returned the civic master cyl and got the acura one today although the acura master cyl doesnt fit on the civic booster! "Thought id try" so Ill pick that up tommrow and bleed them again and attempt to stop.


was there an OEM 1 inch combo that works in the civic?

 

I have a 15/16" MC on my EG with 4 piston Spoons and the pedal feel isn't as firm as my 1" MC on my EK with 4 piston Wilwoods.

If you're still not happy with the 15/16" but it's improved, definitely try a 1".

 

Alright, well is there any modification necessary?
or is it just bolt it all up and ready to go?

 

I had to make a new line because the front outlet of the MC is 12x1 instead of 10x1. there's a factory reducer to mate that line to a smaller line for the prop valve. I don't know if all 1" MC are like that but be prepared BEFORE you put it in your car.

 

Ahh alright, well I'm sure a store that sells fittings will adapt it..

are those usually a dual output master cylinder?

 

All OEM are dual outlet.

 

Oh i guess I was asking, if it was an aftermarket cylinder is it dual output.

but, is there a honda oem replacement thats a 1 inch MC along with booster that works for my setup.

 

I am running a 1" master with brake booster. I believe I got it out of a gsr. everything was bolt on except one line will need to be adapted as mentioned above. If I go near my car I will take pics for you.


Did some quick searching. If you get the 98-01 integra 1" MC you will not need the m12 to m10 adapter. You only need the adapter for 94-97 MC.

 

So, it worked with this setup and the original 13/16 MC until you replaced it, and the replacement is the same size? If so, then how is size the problem, or did you change size in the process? Different sizes could feel better or worse, but if you replaced it with the same as you took off, then it may not be a size issue. Could the new MC just be bad?

 

Ok here's the situation i have the CX booster 13/16th's master cylinder "stock and stock"

so since I have stainless lines and the clearances and my shaved bay "sounds dirty"... I have to put 2 washers on each of the 4 threaded bolts that attach the brake booster to move the position of the brake booster forward an 8th of an inch, I compensated on the pedal by unscrewing the little .... bracket that attaches to the pedal to keep the clearances all happy. "its worked awesome like this for 2 years"

I did this because the front most stainless line since it comes out straight off the master cylinder and if I didn't space it the line would have a problem rubbing up against the upper control arm bolt.

See other forum post at top about my previous experience.
SO

onto the idea

since I have my stainless lines kinda measured to length for the CX master cylinder I'd really like to know what the 1" MC looks like in an EG top side view good photos so I can get a rough idea of what fittings or more/less stainless line ill need to make my goddamn civic stop!


Honestly I have no flipping idea why its worked for 2 years then just took a **** on me like that! its really annoying... but hey 13 inch front rotors on a car is soooooooo fun to stop!

 

Not real likely, but possible to get a bad MC. I bring it up because nothing else changed except the MC, not size. Also, pumping and then working sounds like MC. You get a good pedal without running, bleeding the brakes. Did you get the back seal on, on the MC to booster, and did you get the old one out?

 

Yes I got the old one out.

I cleaned around the inside of the booster where it seemed to be rusted a bit.

It's tempting to try another stock civic cylinder

It's kinda interesting this is really the first part of my build that ive run into problems I'm not sure how to solve.

 

Fixed the problem, it was a bad brake booster.

its not even funny how little brake pedal I need to stop my civic dead!