DIY Brake Master Cylinder rebuild

Awesome. Thanks.

ps. brilliant write up ecu man.

claymore what you mean by catching it?

any chance you can get the pics back up?

Pics still work for me? Nice write up.

My brake is really spongy at the moment. By looking at it I know the Fluid needs to be changed (both clutch and brakes). But how can I tell the difference between needing to rebuild the master cylinder, needing a new one, or just replacing the fluid?

At the moment, if I sit at lights. The brakes get spongy and I can feel it lose pressure/pedal moves around. And braking at speed is basically useless. Like, seriously - I wouldn't drive in front of my on a highway.

The write up is beyond me, I'm asking from a 'she needs to go to the shop' but I don't want them to replace the fluid then find out it doesn't help and needs new master cylinder.

Thanks

sounds like you need to rebuild the master cylinder more that just bleed the brakes.

you look in the bore of the master cylinder to determin the extent to the damage to the bore.

its not a bad thing if you bleed your brakes to find you need to rebuild the master cylinder. brake fluid if very cheep.

take it to a shop if you unsure

Thanks ECU-man. I'm sort of a car newbie but I've managed to rebuild the master cylinder from your tutorial.

At the end of last summer my pedal was sinking to the floor (sometimes) but once it got less hot I didn't have the problem throughout the whole year. Now that summer is back, I thought I'd rebuild it, so hopefully the problem is solved. When you said "check the bore" for damages, what sort of damages were you talking about? The inside of my bore looks pretty clean and smooth, but near the outside edges there were a bit of brownish/greenish stuff? I could clean most of it, but some of it were "stuck" to the metal?

Oh by the way, the kit costed me 64 bucks from Honda North in Perth. (1992 EG Civic GL)

good work

what is ment bt check the bore, is to inspect it for excessive ware and scoreing from the pistons. its pretty obvios when you see it.

most times they are ok.

Hi ECU-MAN,

I'm new at all this. I've brought a 89 Civic with B16a1 conversion a couple of years ago, the BMC and booster was still the original 89 GL ones (with DA integra front rotor/brakes etc, and original civic GL rear drum), and the brake pedal feels really spongy.

I've brought a complete set of CRX Gen 2 rear disc brake (including arms, handbrake cable and BMC) from a wrecker. Got it installed by my mechanic, worked prefect for 3 weeks, then it's gone very spongy again, and a week later, it's gone stiff, and now with brake drag (the brake pad constantly touch the disc).
I can't even drive it down to my mechanic anymore as the brake pedal is now max to the top and I can't even push it down.

Any suggestion? Should i try the DIY rebuild ? My mechanic said to just buy a new one, which could cost about $200.

Thanks heaps.

It's normal for the brake pad to touch the disk.

Could possibly have a seized caliper if you pressing down on the pedal has no effect (and the pedal is hard).

as Wynode mentioned you may have a seized caliper, check all 4

the front pistons in the calipers should just be able to be pushed in quite easy, the rears must be screwed back in. make sure your caliper slides are free to slide in and out for the top and bottom slides. front and rear.

you can try to bleed the brakes again. also make sure your booster is getting vacuum.

just had a question about bleeding the booster/MC

if i were to loop those two holes on the MC back to the MC itself, in theory i wouldn't lose fluid as its returning to the reservoir and as long as i have the hoses higher than the mc itself it would bleed as well correct?

not a good idea, teh fluid that comes out will be airated

brake fluid is not expensive, dont reuse the fluid.