Ok I've got a 91' Civic Dx Auto. Yesterday when I was leaving work the brakes started acting weird. When I press the pedal down it'll have pressure but loses it as I continue to keep pressing it down. Eventually the pedal will hit the floor and I wont have any brakes. I checked the fluid and it was full. Any idea's? This is my DD while my EK is in the garage so I really need to get this figured out. Thanks for the input!

 

Bump. Thinking it could possibally be the brake booster?

 

brake line leak

 

The fluid wasnt empty, so no.

When you press down on the pedal, you lose pressure, but when you lift up your foot, and compress again, you have pressure right?

If you answered "yes", then your master cylinder is going out.

 

+1 On the master cylinder. Mine's doing exactly the same thing.

 

Yup, having the same problem, and I went through the tests in the helms manual, and go figure I installed a bad master cylinder... I swapped over to rear discs and brand new stainless lines, and nothing is leaking on me, my check valve works properly, and the tests for the booster checked out.

 

Might be the Master, But im positive its the Booster, I had the same problems on all my ef's its a very common ef problem

 

Yes if I compress it, it will have pressure then slowly lose it til it hits the floor. If I let up off the pedal it will come back up and do the same thing again. So I've got 2 for master cylinder and 1 for booster. Any more inputs? And thanks this far.

 

Its the MC, if it was the booster..you're brake pedal would be HARD. Plus, you'de have a change in RPM while pressing the booster (diaphram leaking inside booster causing vacuum).

I've done both repairs to my old EF sedan. COMPLETELY different symptoms between the two.

 

Alright thanks. After I posted I read about the symptoms which you explained word for word lol. Getting ready to go get a new one now, am I in for a fun time or will it be pretty straight forward? Thanks again

 

Master cylinder? 2 14mm mounting bolts, 2 10mm brake lines you need to use an open ended wrench.

EDIT: if its not 14mm, they're 12mm. I get confused sometimes haha.

 

Sweet, thanks for all the help.

 

Whenever you have to do the booster....good luck! Now THAT is a bitch to do. Unless of course you remove the dashboard, or drop the steering column.

 

I can do my booster without removing the dash or steering column... I need to find me a 1" MC, because that is what is on my car...

 

What are you using? I have multiple extensions/swivels but the "easiest" way was to drop the column.

 

a 12mm deep socket, an extension, and a swivel... lol works fine for me.

 

Thats really it? are you using a 1/4" rachet?

There are two bolts i could always get loose no problem. But two are pressed very tightly against the framing for the dash.

I dunno, more power to you but haha i dont want to be removing these things weekly! Im glad i got the EX, those brakes are frickin amazing.

 

Alright got the new master cylinder, trying to remove the old one. I got the lines off and the 2 12mm mounting bolts but it wont come off. Is there something I'm missing? I looked around to see if I could notice anything else but I didn't see anything. I don't want to force it and break something that might be holding it on.

 

The two mounting bolts go from the MC, into the brake booster...just grab onto the MC and pull it straight outward towards the shock tower. It WILL come off, just might need some persuasion.

 

Alright I've been prying on it a little bit but nothing to much. I'll go out and try to give it some "Persuasion" lol.

 

Brake master cylinder.