Finally got a chance to take my car down my block and what do i find yet another problem. I get an extremely soft pedal.
It goes all the way to the floor.
First thought, maybe one of the pads is expletive and pushing the piston out. Nope check all four and all have a good amount of pad life.
I bleed the brakes manually with pumping the pedal and popping the bleeder, no vacuum pulling or anything.
Im not losing fluid so its not going somewhere.
The pedal gets hard when the car is off, so its leaving me to think it has something to do with the booster.
I am just open to other suggestion.
Also since i never work on EF's before do our cars normally have a check valve from the booster to the manifold.

Car in question is a 1991 CRX SI. I know it doesnt really matter just in case someone wanted to know.

 

yes, there is a check valve between the booster and supply vacuum. I don't think you have a booster problem... typically a booster problem causes much more f**ed up problems than this. It sounds like 1 of 2 things: either you still have air in the lines, or you have severely misadjusted rear brake shoes. Too much slack in the rear will make your pedal travel very far before you get much braking. Can you pump the pedal with the engine running and temporarily get some pedal? The pedal getting firmer with the engine off should take probably about 2 or 3 pumps, which is normal operation. There's also the possibility that your master cylinder is bypassing. If you are sure you have no air in the lines and the rear brakes are nice and tight, that's where I'd look next.

 

That DIY tool to bleed brakes does not really work. Have an assistance actually pump the brakes and hold it and you open the bleeder screwand shut the pumper should feel pedal slowly fall to the floor. Have them keep pumping and ask him if it is getting firmer as he pumps. There should be absolutly no air bubbles and dirty brake fluid. MAKE SURE WHEN YOU OPEN BLEEDER SCREW EVERYTIME CHECK FOR FLUID LEVEL IS AT MAX. If low you just let air again. Keep another assistance to look at level. Can't be at the same place at once. This should be the problem. A simple and accurate job well done should and will solve brake help. Good luck.

 

If you had a booster problem you would have a very hard pedal, not soft.

As others said already, you need a 2nd person to bleed brakes, unless you have a shop air powered vacuum bleeder.

 

Well that is how i have bleed the brakes. I dont know of any other way. But maybe ill try it again. I will also check the rear brakes. That might have something to do. So i know now its not a booster problem i will keep troubleshooting the calipers and lines.

 

exactly how did you bleed the brakes? this may help us diagnose of you did it wrong or not.

 

You pop the cap on the master. Have someone pump the brakes a couple times and you pop the bleeder until a constant stream comes out. I just repeated this step. Even went and got a hand held vacuum pump to help pull some more out and nothing still.

So this time i wanted to see how it feels just with the car on and not moving. I have a complete soft pedal. Goes all the way to the floor every time i pump, and i pump it several times in a row. So geez im stump on this one, since i have never had this kind of problem with brakes before. Tomorrow im going to pull off each caliper and see if something might be wrong there. I doubt it. But i am running out of ideas. I also look around the car its not losing fluid after i pump the brakes with the car on for almost a minute straight.

 

how old is the master cylinder?

 

Umm your guess is as good as mine. Lets see 1991 car. Year now 2007.

16 years old? Haha.

 

to start i would replace it...long overdue anyways..

 

So i would say the whole booster then, no? Not just the master cylinder.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by duckmanEG &raquo;</TD></TR><TR><TD CLASS="quote">So i would say the whole booster then, no? Not just the master cylinder.</TD></TR></TABLE>

good call, the booster gave in on my previous hatch...the chassis had well over 200k miles so i would

when the booster starts to give the pedal will start to get hard, then eventually leak vaccum and the car wont brake for ****...

 

Well im going to look for one tomorrow. Call a couple people. Hopefully someone has one. Thanks. I will let people know how its goes. I am going to guess no good.

O yea i also find the troubleshooting guide in my pdf filed crx manual. Going to give that a try first. Has some good tips.

 

i'm not sure if you stated how it went to the floor. My master went out on me a few years ago. the condition was the pedal would generally travel further and the longer it was held it would continually sink to the floor, slowly. At a stop light persay i'd end up having to pump it up once usually or else i would have been tboned. I don't think it's too common for boosters to go out on civs, so unless you have leakage from your master into it, i wouldn't fool with replacing it. hope it helps.

 

Ok so i did one of the test from a trouble shooting section.

With the car off, pump the pedal several times then hold hard for 15 seconds. If the pedal sinks a brake line, a wheel cylinder, or the master cylinder is bad.

Well my pedal sinks. So i dont think its a brake line since im not losing a bit of fluid. How do i check the wheel cylinder or better yet, where is it. I googled an image and i dont think i have ever seen that part.

I also did the test to check the booster. Which is: Put your foot on the pedal and start the car. If the pedal sinks slightly, the vacuum booster is working. So looks like im going to go buy a new MC real fast and try that.

Edit: Rear disc do not have wheel cylinders do they. That is for drum brakes???

 

yeah, wheel cylinders are only on drum brakes...1 bad caliper wont cause the problem you are describing, and i doubt there's more than 1 bad caliper....

 

Well i just replaced the MC since i pretty much ruled out brake line, and no wheel cylinders for me. So far it seems better i can stop with out the pedal slamming into the floor. Just need to bleed the brakes again now since of course i opened it up. Also the problem with the car being off and sinking when depressed is gone.

Well i guess this goes in my master cylinder is expletive up. Didnt think what i had would have been a MC, im not completely braking yet, but i am sure after a good bleed job it should help alot. Thanks.

 

and just a side note...when pumping your brakes during bleeding...DO NOT GO ALL THE WAY TO THE FLOOR... I found that out the hard way back in the day...went through 2 cylinders while bleeding my brakes

 

I see. Thanks for letting me know. Any how bleed the brakes and they stop now. But i have tons of pedal play. I like a firm pedal right away. Since i am done working on the car in the 90 degree weather for today. Since i dont feel like going back out to look.

Can the pedal be adjusted?

 

did you remember to check and make sure there was only one rubber grommet on the master cylinder?

i replaced the MC and booster at separate times. so when i put te new MC on i accidentally left the old rubber gasket/grommet/thing on the booster because it was stuck and i didnt realize. then when the new MC went on with its new rubber piece it blew out my brand new MC because of the double rubber things. so i had to get another new MC and redo the whole process. so now i always check before bolting it down.. did that rubber thing stick? ha ha

hope yours didnt.

 

It took me two times to get them to feel right. Since no one mentioned it did you follow the recommended pattern to bleed them?

Do left rear first
Then do the right front
on to the right rear
And then the left front.

Honda's are a little different.

 

Did you try bleeding the MC itself before you bled everything else

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 89civicdx &raquo;</TD></TR><TR><TD CLASS="quote">Did you try bleeding the MC itself before you bled everything else</TD></TR></TABLE>


good idea. i forgot. BENCH BLEEDING IS ALSO COMPLETELY NECESSARY!

 

Yes i bleed the MC first.

What rubber thing are you talking about .kyle

 

on the end of the master cylinder closest to us in the picture.



on the thing you push in to bench bleed it. i didnt realize my old one was stuck on the booster when i put on the new MC and i ended up double gasketing it.