Brakes wont stop! help ASAP

[jsuh s14]

okay. so here i am with a brake problem screweing me over. i thought i had a leaky rear right caliper, so i went out to a junkyard and bought another one. replaced it, and braking was better. still shitty but better. now.. (about 5 days later) my brakes wont work for shit. i press the pedal down ALL the way to the floor mat, and the car still takes a really long time to drop.. id say about 15-20 feet traveling at no more than 25 mph. so.. what to do? i dont see any leaks, the fluid in my resirvior isnt much lower.. so whats the problem? also, these is a "dead spot" in the early stage of braking. when i press the brakes for about 3-6 inches down, the car seems to not stop, or stop VERY slowly. Also, i have bled to brakes to a degree, but have not flushed out the entire sytem. please help me guys. thanks

[s13silvia123]

um did you bleed your brakes the right way from the furtherest caliper from the MBC then to the nearest.

[HellonFire]

Bleed the brakes... Or possibly a bad Master Cylinder.

Tyler

[sr240dett3]

I have a similar problem.

I just did a full Z32 Brake conversion on my car.
4 calipers, SS lines and master cylinder, etc

I have bleed the brakes twice now. If i pump the brake pedal it will get stiff.
But if i stop pumping for about 2-3mins and apply the pedal again it goes to the floor.

I have spoken to a couple people and they say it still has air in the lines.
There aren't any leaks.. i checked all the connections..
So i plan on bleeding it maybe another 2times. until i get it right.

So i recommend that you ge a big bottle of brake fluid and bleed your brakes.

I have my car in the air right now so its a little easier, instead of having to take wheel off at a time.

Good luck

[HellonFire]

I have a similar problem.

I just did a full Z32 Brake conversion on my car.
4 calipers, SS lines and master cylinder, etc

I have bleed the brakes twice now. If i pump the brake pedal it will get stiff.
But if i stop pumping for about 2-3mins and apply the pedal again it goes to the floor.

I have spoken to a couple people and they say it still has air in the lines.
There aren't any leaks.. i checked all the connections..
So i plan on bleeding it maybe another 2times. until i get it right.

So i recommend that you ge a big bottle of brake fluid and bleed your brakes.

I have my car in the air right now so its a little easier, instead of having to take wheel off at a time.

Good luck

I can bet you that you don't still have air in your lines. You put the calipers on the wrong sides. The bleeder valves need to be on the top of the caliper when they are installed. Run outside and check. ;)

Tyler

[speedstar01]

exactly what those two guys above me said. bleed your brakes starting from the caliper furthest from the master cylinder until you get to the one closest.

if the system is completely bled (the proper way) and you are still experiencing bad braking and a "sinking pedal" then it is most likely your master cylinder. hope this all helps, let us know how you do :)

[jsuh s14]

thanks people. like you guys were saying, i did bleed from the furthest. however, not the front left. the brakes felt solid after bleeding three of them. so im guessing master cylinder? how much would they run me? will a R33 GTR master cylinder be able to be used on my 97 s14 sr20?

[sr240dett3]

I can bet you that you don't still have air in your lines. You put the calipers on the wrong sides. The bleeder valves need to be on the top of the caliper when they are installed. Run outside and check. ;)

Tyler
Car is in my garage across town, ill be real upset at my self if thats my problem.
I cant say i remember if they are up or down


Now that i think about it, they might be down, instead of up.

[sr240dett3]

thanks people. like you guys were saying, i did bleed from the furthest. however, not the front left. the brakes felt solid after bleeding three of them. so im guessing master cylinder? how much would they run me? will a R33 GTR master cylinder be able to be used on my 97 s14 sr20?
I personally would get an S14 OEM one.

WHY?

If you start applying more braking force to your stock little calipers, you could possible lock the wheels when you try to stop.

So unless u get bigger brakes, just get the OEM Brake master cylinder.

It shouldn't be 2expensive, just get a Re-Manufactured one

[HellonFire]

Now that i think about it, they might be down, instead of up.

Yeah, its very easy to do if you aren't paying attention.

If you have the valves down, it doesn't let the caliper fill up with fluid before bleeding it out. And that leaves you with no pressure.

Tyler

[sr240dett3]

Sorry for the Tread Jack

Yeah, its very easy to do if you aren't paying attention.

If you have the valves down, it doesn't let the caliper fill up with fluid before bleeding it out. And that leaves you with no pressure.

Tyler
Yea first thing i am doing on Thursday *(day off)* is checking that.

Thanks

[kandyflip445]

Also when installing MC's you should bench bleed them prior to putting them on the car.

[ixfxi]

Yep, you fuckers have air in your lines... that, or your master cylinders are not functioning properly.

If you guys are doing shit like installing brake calipers backwards or not bleeding them properly, you really should consider paying someone to work on your car for you - OR - do more research and practice more. This type of work is not hard at all...

[HellonFire]

No reason to be an ass. Not like he put the brake pads on backwords or anything. And plus, with stock calipers there is no backwords, so one wouldn't think that with Z32 brakes there would be a wrong side.

Tyler

[ZodiacSR]

Theres also one item you should check, have you checked the valve that runs between the intake manifold to the brake booster?

Theres a plastic white valve thats runs between the lines that go from the intake manifold to the brake booster. Just follow the line from the brake booster and you'll find a connection in the middle.

That might be the problem.

[HellonFire]

Haha, you have to tell them what to check!

And it wouldn't really be the cuprit of soft brakes.

Its a one way valve, that controls the air going to your Brake Booster.

If it is in there backwords, you will have no help from the motor, and when you boost you will not be able to push in the pedal.

Or if its broken, meaning air can flow both ways, then you will have normal operation when motor is in vacuum but won't be able to brake under boost.

To test it, just pull it out and make sure you can only blow through the direction that the arrow is pointing.

Tyler

[slider2828]

Did you pressure test your booster as well? You can borrow a vacuum tester from Autozone and do a pressure test on the booster or you can just have a mechanic do it. Mine failed because it was just old.

[!Zar!]

Hahaha. You all have air in your brake system.

Could be a brake booster but that's fairly unlikely being as how it was working fine before you replaced your brakes.

Bleeder going up is common since. Since you want to bleed air out of your system, and not fluid. Duh.

Putting a skyline mbc on a car with stock brakes is dumb.

You all really should check your work carefully. What if your brakes failed when you're coming off an off ramp.

[MadScientist]

You are all wrong!!!!

As was I when this was happening to me.

If you replaced the Master Cylinder and did a Full Z swap then you need to adjust the Plunger (dunno what its actually called)... Its on the Booster in the middle... Yes, the little Rod with a nut cap (8mm).
This will take a few tried to get the right feel... You will be taking the MC on and off after every adjustment and testing by lettingthe car roll under its own power. If the car wont roll then you have the Plunger to far out.... If you have pedal drop then you need to adjust it out!

Enjoy...
Peace
Drew

[kandyflip445]

^^There is a thread in the FAQ section about that too. Along with a full brake thread. :)