just put some slotted and drilled rotors with new pads on my car. when i started the car up io pumped the break to get the pressuer up. i drove it up to 30-35mph and hit the breaks and the car stopped real nice and hard like it did with the stock stuff. I was driving down the road and i had to stop for 65mph and the break went to the floor and i had no stoping power. I pump the pedal to see if the breaks work and now they do. but the car is still stoping slow. any ideas?
using stock break pads too if that helps at all

 

Bleed your breaks
(it's really brakes)

 

Most likely you got a leak or air in the brake lines.

 

Did you bed-in the pads?

http://www.zeckhausen.com/bedding_in_brakes.htm

 

a. Brake fluid is low.
b. Air in the brake lines.

 

c. All of the above.

while your doing the bleeding it would be a great time to flush the fluid with synthetic!

 

Be careful about using the word "synthetic" when discussing brake fluid and the Z. True synthetics (DOT 5) are not compatible with the brake system and will damage the seals. Make sure you are using a DOT 3, DOT 4 or DOT 5.1 compatible fluid.

 

All brake fluid is synthetic by definition as no natural pools of brake fluid occur on Earth. Anything 100% man made is synthetic.

Just a name marketeers use to confuse non science majors.......the bulk of population.

 

sorry, next time i'll be more specific.

Motul 600
ate super blue
or Valvoline High Perf Synpower

see link for some good info.
http://www.swedishbricks.net/700900F...Comparison.htm

 

You must fully bleed your brakes.. And by this i mean have a bottle of brake fluid and all of your wheels taken off so you can undo the nipple cover.. Proceed to bleed them until alot of the old brake fluid is gone.. start filling it with new brake fluid (Someone must pump the brakes while you ensure they are bleeding) You must get all the air out of the system or you will never brake right.....

 

Bleed brakes and look for leaks. Is the fluid low?

 

Bleed your brakes, if that doesnt resolve it, you put to much air in the system and damaged the master cylinder. Most likey though its just air in the system, bleeding will resolve this.

 

We see so many untrained incompetant [de de dees and home] mechanics push the calipers back in without draining the decomposed temperature challenged used brake fluid.

Owners don't seem to understand that the fluid temp rises as the pads get thinner losing their insulating properties.
Anytime brake fluid EVER BOILS it must be immediately replaced as the boiling and/in moisture causes a reaction decomposing it into an acidic mix attacking the neoprene seals in calipers.

With ABS/ TCS you must be EXTRA CAREFUL or you will take days to get the trapped air out..............why we use expensive bleeding machines. One lazy tech can ruin a days production.

Shows machine and how to use it:
http://www.mercurymarauder.net/forum...d.php?p=470310