1991 240sx SE: Brake problem again.

[xckid]

Okay well i been having brake problems for a while now.

What happens is after awhile of driving and braking the pedal feels stiff. So though nothing of it i get home and theres smoke coming out of the front tires as if the brakes werent realsing. And thats how it felt when i was like it was still braking. So i go to my uncles he says it might be the rubber brake lines. Replace it still does it. So i posted here and was told they are seized . Replace the calipers, both sides still nothing. I am out of ideas. what can it. be.

[NISTECH]

What kind of brake fluid you got in it? How does the fluid look?

[xckid]

It is Valvoline Syn Power Synthetic Formula Exceeds Dot 3 & Dot 4

In the Master Cylinder it look of a light yellow.

[NISTECH]

You cant mix some "performance" break fluids with dot 3 or dot 4 or it will cause the system to gum up. you may have this problem with this fluid in the master cyl bore.

[xckid]

So replace the master cyl and change the fluid in the system. How do i change the fluid. One more just incase this aint it, could you give any other possible things that myabe wrong. That are causing this. Thank you

[xckid]

bump so what i replace it or check it out?

[NISTECH]

Try draining all the fluid in the system COMPLETELY. Then by standard fluid and bleed the system and see if you have an improved braking condition. If it doesnt improve the situation then replace the master and recheck it.

[xckid]

How do I drain the fluid. And what do you mean by standard fluid Dot3 ?

[XxBLiNdxX]

Just check the package of the brake fluid. It should say DOT 3 on it. I had a similar problem with my car with the brakes smoking from engaging. I had a vacuum leak in my brake booster, if you had the same problem you shoudl hear a loud hissing noise on the other side of teh firewall.

[xckid]

It says exceeds Dot3 & Dot4 . Thats all it says. Do i have to have the car on to here the hissing sound. If i do how do i fix it.

Okay well i just turned my car on and started it. i hear a hissing sound from the inside, but im not sure if thats normal. Turned the car off didnt hear anything. arghhhhhh.I want my car to work.
Modified by xckid at 1:40 PM 11/13/2005

[NISTECH]

The big hose connected to your brake booster. unhook it from the booster and plug the hose so your car will start. Then fire it up and see if the hissing is gone. If it is then you have a vaccum leak in your booster.

[xckid]

Okay so i unnplugged the hose then my dad plugged it with his thumb(thank you dad.) And hissing was gone. So i turn the car off put the hose back and and started it up again and hissing sound was back. SO narrowing the problem to vaccum leak what do i do . Also my car started faster when my dad plugged the hose. once it went back it took a couple seconds to start. Can a vaccum leak do that.

[NISTECH]

You have a leaking diaphram in your booster,replace it its not repairable. Yes a vaccum leak can cause a car to be difficult to start.

[NISTECH]

BTW good call Thomas!!

[xckid]

Thank you i will be replaceing the brake booster.

[ricebike]

to add: that valvoline synpower fluid is OK to use... it's no "High Performance" fluid like DOT 5.1

I'm using it on my braking system/no ABS...

[xckid]

umm since i cant seem to see the post i just but on the first page i ll bring this one back. I fixed it and now i have a high idle and the srew wont go back anymore idle is 900~1000 i think i also have leaking rear caliper seal casue there is a lot of gunk on one and i lose brake fluid fastthanks if the other show then just ingnore this one.