I'm having a few issues with my brakes, symptoms below:

- A few days ago I noticed that when at a stop my brake pedal would start slowly dropping to the floor as if losing pressure accompanied with the car slowly rolling as if the brakes are not clamping down anymore. I'd pump the brake pedal a few times to get pressure back up only to experience the same issue again. Had to do this just to keep from rolling forward or backward into anyone just as a temporary bandaid to get home

- When car is off the brake pedal is stiff again. I press the brake pedal and it will again drop to the floor but a lot more slowly than when the car is on.

- I had to keep pretty big distance from other cars 'cause when I press the brake pedal it would start out normal but then the pedal will drop to the floor slowly while the brakes start to lose braking power. I had to pump the brake pedal a few times to get enough braking force to stop or slow down.

- The brake fluid is at max, front pads are still good, and not sure about the rear since it's drums.

I was thinking of bleeding the brakes to see if that would remedy the issue but a friend told me it may be a the MC going out. What do you guys think?

 

mc is gone

 

Second that. Rockauto has'em cheap.

 

Awesome Im a newbie and this is something i know...I had the same prob. with my 89 crx dx. I put a new mc on it havent had the prob. since I had a guy the specifically works on honda tell me that. he said after so many winters and summers its expands and contracts till it doesnt work properly any more. so yea these guys are right thats the part you need.

 

Alright I'll be picking up an MC locally. How much brake fluid should I get?

 

A bottle or two should be fine depending on if you bleed the brakes and don't run into any issues.

 

Thank you for the help, kind sirs/madams.

 

Dumb question alert!

Do I need to drain all the brake fluid to replace this?

 

you flush the fluid by pushing out the old fluid with new fluid until all the old fluid is out.

NEVER let the brake system empty. at least not if you can help it.

 

No, but keep the stuff from leaking onto your paint. It will eat it away in a big hurry. Be sure to place plenty of rags or towels under the two lines you must disconnect from your MC. Also have some soapy water on hand to quickly wash off any fluid that gets onto the paint. Even the black paint on the master cylinder will peel off if brake fluid is left on it.

Also, your new MC should have two fittings in those two connection ports with nipples on them for a process called bench-bleeding. The idea is that before installing you place short pieces of clear hose over each nipple and feed them back into the reservoir. Fill the reservoir with brake fluid and pump the rod with your hand many times over (only press it in half way to avoid internal damage). Keep pumping until no more air bubbles are seen inside moving through the hoses. Once done you can remove the hoses and fittings and install the new MC. again keep plenty of rags on hand because it will want to drip once those nipples are removed. Sometimes the new MC won't come with those plastic fittings so you'll just have to skip the bench bleeding. This is okay, but it makes it take longer to bleed the brakes out when your done.



A non-honda picture for reference:


Also get yourself a 10mm/12mm flare-nut wrench to avoid rounding off the brake line nuts when disconnecting or reconnecting them. They cannot be replaced without cutting the hardlines.



When your all done, you must bleed the entire brake system. That is a whole other story. The proper sequence can be found on here or in the oem shop manual. And don't ever believe anybody that says bleed the furthest wheel from the MC first. I've done many many Hondas and not ONE of them goes in the old "furthest-to-closest" order. That is a myth. I think the CRX goes LF, RR, RF, LR, but I'm not sure.

 

More dumb question alert:

How do I drain the fluid out from the MC before swapping it out then?

 

You can suck i out with a turkey baster, or just leave it in there with the cap on. Either way fluid is going to dribble out of the two ports when you disconnect the hard lines.

 

if i dont have a turkey baster handy, i just stick a paper towel in there, soak up as much as i can.

just dont let it run dry, let something remain at the bottom before filling up again.

 

If you are replacing the MC then a little air in your lines isn't going to hurt.
You are going to get air in the lines anyway when you take out the old MC.

Just open one of the bleeders at a wheel and pump out the fluid from the MC.
After the MC is dry DO try to keep as much fluid in the line as possible.
You do not want the calipers to run dry.

 

Thanks for the tips, guys.

 

Alright took care of this this past weekend with the help of a friend to bleed the brakes. Pain in the *** 'cause I only have two jack stands. I really need to stop lagging on buying another two....

Totally unrelated question but ever since I replaced the brake MC my car has been having an erratic idle. It seems to keep revving between 1k and 1.5k RPM's when warmed up. Didn't do that before I swapped the brake MC. I checked any rubber lines in the vicinty of the MC and they all seemed fine. You guys have any other ideas on something for me to check in that area that I may have messed up while working in the vicinity of the MC?

 

There are a lot of vacuum hoses in that area. The MC is not directly connected to any of them, but the brake booster is. Though I doubt you could have damaged the booster, you could have definitely knocked one of the hoses loose. I would just go through the area and triple check before I started worrying about the booster.

 

you may have not taken out the old gasket that was attached to the master cylinder that seals it to the booster. its a typical mistake, where you pull the old MC out and the gasket is still stuck inside the booster and you just throw the new one on with a new gasket, so it has 2 gaskets in there.

this would cause a bad seal.

otherwise, you may just have a vacuum leak anywhere else. or a bad booster or check valve.

to determine if its a bad booster, follow this test.
http://www.norcalcrx.org/tyson/pics/braketest.jpg

 

Your reply led me to check the gasket and I found that I did something dumber. I pulled the gasket off with the rubber dust cap on the end of it when I pulled it out of the box. Luckily I'm a slob and left the gasket on my workbench. Idles fine now. Thanks!

 

win.