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really need help. brakes dont work!

2K views 24 replies 8 participants last post by  18camaro 
#1 ·
i drive an 81 camaro sb 350. so the other day i was driving and noticed my brakes werent working properly. i could pump them and that seemed to help but the pedal just goed to the floor otherwise. i replaced the master cylinder and it still doesnt work. i even got a second master cylinder because i maybe that one could be bad and the new one doesnt work either. so i rele need help i need my car to get to work. thank you for your help
 
#6 ·
Pull the rear wheels off and then the brake drums. The cylinder is at the top, it is what the brake line is attached to. If there is any wetness near the ends of the rubber dust caps, they are leaking.

I have a couple questions
1 after you pump the pedal and you get brakes, if you stay on the pedal does it go back to the floor or does it stay high until you release it?

2 What was the original issue?

3 have you tried adjusting the rears ?

If you have never done it before, replacing those wheel cylinders can turn into a nightmare, the lines tend to break on a vehicle that old and a simple job can get real nasty real quick.

The other thing is these are your brakes, if you are not 100% sure what you are doing, take it to someone who does before you kill yourself or someone else.
 
#7 ·
well originally when i pumped them id get a pedal and itd go down but now it gets harder but still goes down alot and then goes all the way.

i was driving and they got worse and worse. luckily its a stick so i down shifted

how do i adjust the rears? would that cause this problem?

how can the rear brakes affect the front?

my neighbor is very expierienced with cars so hes helping me. he thought it was the master cylinder but when that didnt work he mentioned something about the rear. the reason im asking on hear tho is because 2 heads are better than one and hes busy alot so all your help is greatly appreciated
 
#13 ·
I has to be either air in the lines or you have a leak some place . Are you sure you have all the air out ? Also how old is the brake fluid ? You might consider about changing it . It does go bad . Have someone do the brakes while you start checking all the lines , the rear wheel cylinders and the front calipers . If you can't see anything then put the car on jack stands and pull all the wheel and inspect everthing real well . Clean everthing while you have it all torn apart with brake cleen . Make sure your rear brakes are adjusted . That is what I would do !
 
#14 ·
You have a leak. If you can pump the pedal up and then it slowly goes back down there is a leak somewhere. Is the fluid level in the master cylinder going down. Once you fill it it should stay filled unless it is leaking.
I also would vote for a wheel cylinder. Look at the backs of the rear tires for fluid or a mud like buildup?

If it is a wheel cylinder, change both sides.
 
#16 ·
Loss of brake peddle

I aggree with the guys that a leak is likely your problem and you have already had advise on how to check and repair that.
In the event you have no leaks or air in the system THEN
IT MUST be adjustment at the rear shoes. (measure your drums your shoes should be adjusted to give a small amount of drag) also your drums may be oversize. (this sould help remove some exessive peddle travel.
There is ONE More place you can loose your peddle . IF YOUR FRONT CALIPERS ARE STUCK (not sliding freely) Your piston will have to travel too far for one pump on the peddle. You may have noticed week braking and may have noticed a pull to one side or the other for some time. If it pulls to one side when you brake it will be the opposite side thats stuck. ( check your front pads see if one is almost worn away and the other not waring at all. Their are two small tubes mounted in orings that suport by the two caliper mounting bolts .These tubes should slide in the orings allowing the caliper to centre over the rotor each time the brakes are applied. This allows both pads to apply with minable foot travel
CQNRQY :pimp:
 
#20 ·
18camaro said:
my neighbor thinks something is wrong with the porportioning valve so we are gonna look at that and see
I agree with T-bucket23 the porportioningn valve has nothing to do with what you have described in your post.all it does is regulate the flow front and rear.it is a pressure thing so you could adjust it so the front brakes will brake slightly before the rear. cole
 
#21 ·
Start by bleeding the furthest wheel away from the MC. I once had a 80 Chevy truck that I could'nt get the brakes working correctly even by conventional bleeding methods. What I did to get them to work is to gravity bleed them. All you do is open up the bleeders and let gravity do the work. It takes awhile but it will work and is usually less messy that pressure bleeding. Just keep a pan under the bleeder to catch the fluid and keep the MC full. It may take 2 or 3 hours to bleed this way so buy plenty of beer.
 
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