Alright, my brakes suck.
hehe, what's happening is that they will gradually go all the way down to the floor and there is moderate braking ability at the floor. anyway, is it the master cylinder or slave? also, there is no fluid loss in the slave cylinder. i need help!!!!!!
Josh

 

Brakes don't have slave cylinders. All power assisted 4 wheel disc cars have is a brake boster, master cylinder, and proportioning valve.

 

oh, shows how much i know (or don't know)
hehe. okay, so what's my problem? bad master cylinder?
Josh

 

Here's my 2 cents based on my limited experience doing my brakes during the last few years:

I think it could be a few different things.

I'd say try flushing the system with new fluid and bleeding it all out as a first step, see where that gets you. If it's still no good, open things up and check the condition of your pads and shoes (if you have drums) before you decide your master/booster is shot. If everything is good but you still have this problem, it's probably the master cylinder. I don't think the boosters fail very often, but it does happen.

I've had your exact problem before (actually worse, my brakes would hardly work at all), and ended up unnecessarily replacing my booster - only to find out my rear shoes were on the metal and overworking my front brakes till they faded to ****, plus my fluid was toast. In my experience the rear drum brakes, though they do only a minority of the braking, contribute a lot to how responsive and sensitive the brakes feel.

BTW I'd really recommend some Hawk HP+ pads and good racing fluid, you'll think you just installed a big-brake kit.

Good luck, brakes are always a ****** mystery to me compared to other stuff on the car.

 

i'm thinking that the fluid will help out.
i'll try that this week. thanks man
Josh

 

No problem, hope you get it worked out. It's weird, right now I've got the brakes on my FB working better than they've ever been. Hell I'm accidently locking them up at like 140 kph on moderate pedal pressure, with pretty good tires. But I know it won't last too long, that's the shitty thing with brakes lol. One minute they're good, before you know it you gotta **** with them again. And if you bring them to a shop, forget it, you're getting ripped off for sure. Man, I'm getting pissed off just thinking about it lol.

 

it's funny, cuz you'll call a brake shop and they'll tell me that it'll be like 200 bucks for a full job, and extra for any problems. hell no!! i'll go learn how to do it myself and spend like 50 bucks on everything!! what's the easiest way to bleed the brakes?
Josh

 

get a partner. Start at the caliper furthest away from the master cylinder(passenger rear).

Have partner pump brakes 4 or 5 times and then hold the pedal down.

open bleed screw, observe color and presence of bubbles.(easiest way to do this is to put a clear plastic tube to a glass jar on the bleeder nipple)

close bleed screw. have partner repeat. and continue process untill no air and pretty (not dark) brake fluid comes out bleeder.

move to next closest caliper and repeat

NOTE: be sure to continuously check master cylinder brake fluid level as you go. If you run out of fluid and get air in the system you will have to start over.

ANOTHER METHOD:the gravity bleed method is where you open all the bleeder screws and let them bleed themselves over a fairly long period of time. while of course monitoring your fluid level.

I need a set of speed bleeders as I can never find a partner when I need one and have no time for a gravity bleed.

 

spend a few bones on speedbleeders, then goto a pet store and get fish tank air pump hose. Put the speed bleeders in as directed, put the hose on the nipple, the other end in a can, and pump the pedal (topping off the master cyl with fluid every few pumps) until the hose starts showing clean fluid coming out. Start w/ the farthest wheel away from the master (Right Rear) and work closer (Left Rear, Right Front, Left Front).

Without speedbleeders, you've got to have a friend The procedure is the same, but your helper has to tighten the bleeder when your foot's on the floor, and loosten if after you raise the pedal back up (so you don't suck air into the system (very bad)).

W/ speedbleeders, you can do the system in about 15 minutes, less if you have 4 jackstands and can just wander around the car w/ your hose and can. W/o, prolly 1/2 an hour to 45 mins depending.

I'd check your rear shoes first tho, my winter car does the same thing and I know it's because the rear shoes are SHOT, and not doing ANYTHING.

--matt

EDIT:
yaya, you beat me. damn, I must type slow

 

he has a gsl, no shoes.

 

heh, well the procedure is still the same, albeit a tad easier, since the bleeders on the calipers are easier to get at than the drum brake bleeders

 

and the first gens only have one rear bleeder on drum equiped cars. the other side (drivers?) has a brake fluid line going in and out to the other wheel cylinder

 

Look at the vacuum booster - is the paint wet/ruined underneath where the master cylinder is attached?

It sounds like your master cylinder is bypassing internally. Usually a bypassing master will also be drooling fluid out of the back, and brake fuild eats paint, so looking at the vacuum booster is a good tell-tale. Changing the fluid may help, but in my experience it either does nothing, or makes things worse.

BTW you don't want to tlet that go for too long, if it is a leaky master - besides the obvious problem of poor brakes, the brake fluid will also leak into the vacuum booster and eat away at it internally, and cause it to leak vacuum to the master cylinder. When that happens, the vacuum applied to the back of the new master cylinder will destroy it rather quickly. So, ah, make sure you get a master with a good warranty.

 

Update!!!!

I was mistaken in my statement about there being no fluid loss in the cylinder. Actually, i am right, but that's just because the damn thing is full to the max!! should i bleed the cylinder first and see what happens? but, yeah the cylinder is full the brim with fluid!
josh

 

Check to see that there are no foreign fluids in your master cylinder too. At the shop, I had an Isuzu Rodeo come in with the pedal going to the floor and poor brakes.

Replaced the rear shoes which were paper thin and flushed the system with clean fluid.

The cap didn't fit the mater cylinder was one of the first things I noticed. At first, I though someone just put the wrong cap on. The master tech at my shop told me petroleum causes some rubber to swell up.

Someone had put Power Steering Fluid into the brake fluid. On closer inspection, I saw the clear/yellowish blobs of petroleum based P/S fluid floating in the clear/yellowish brake fluid. (Also the P/S resivour was right next to teh master cylinder...

Jiffy Lube cost that guy $300 bucks, Plus labor.

You can check by taking a CLEAN turkey baster (Thoroughlly wash the one you use for ATF.) and Dropping some of your old brake fluid into a cup of New brake fluid or a cup of water. Any foreign fluids will clearly be seperated out. (Brake fluid is hydroscopic. It absorbs water. Any petroleum based liquids will float on the water.)

 

Check to see that there are no foreign fluids in your master cylinder too. At the shop, I had an Isuzu Rodeo come in with the pedal going to the floor and poor brakes.

Replaced the rear shoes which were paper thin and flushed the system with clean fluid.

The cap didn't fit the mater cylinder was one of the first things I noticed. At first, I though someone just put the wrong cap on. The master tech at my shop told me petroleum causes some rubber to swell up.

Someone had put Power Steering Fluid into the brake fluid. On closer inspection, I saw the clear/yellowish blobs of petroleum based P/S fluid floating in the clear/yellowish brake fluid. (Also the P/S resivour was right next to teh master cylinder...

Jiffy Lube cost that guy $300 bucks, Plus labor.

You can check by taking a CLEAN turkey baster (Thoroughlly wash the one you use for ATF.) and Dropping some of your old brake fluid into a cup of New brake fluid or a cup of water. Any foreign fluids will clearly be seperated out. (Brake fluid is hydroscopic. It absorbs water. Any petroleum based liquids will float on the water.)

 

Damnit! Server busy messages.

 

cool. thanks Pele.
I'm gonna flush the system this weekend. hopefully my pops will be in town to help me.
Josh

 

alright, i traced the problem down to a bad right rear brake piston. the boot around it is busted and the fluid is leaking out. not good! getting a new one in today, gonna pop it in and hopefully no problems. i checked out the other rear side and replaced the pads that where worn down. my main problem was how to get the piston back down!! damn!!! then i talked to my mechanic and he showed me. damn japs! hehe, anyway i am stoked that i fiugred out the problem and learned.
but damn, i hate my brakes.
Josh