So I installed new pads and rotors and my car brakes like shit

[Natty]

I put new pads and rotors on last week and broke them in. Now my pedal feels a bit soft and the car brakes really poorly. Any ideas of what is causing this?

I did not change the fluid and it is 2 years old. I also opened the cap on the master cylinder when pushing the piston back in. None leaked out or anything. It may have something to do with this.

[ThatGuy]

This is a Tech Question, therefore it belongs in Tech Talk.

[crioten]

did you bleed the brakes? im going to bet thats the problem

as long as no air got into the lines when you opened the cap, you should be fine (like there was fluid in there when you opened it... and it didnt suck any more in)

[mr_240sx]

does keeping the same fluid in for a few years affect the braking effectiveness?

[holisticbeatz]

It shouldn't.. Though the fluid may become dirty after a long while, it shouldn't affect braking effectiveness.

Did you during your installation introduce air into your system? A tiny air bubble can cause big problems. Try bleeding your brakes and putting fresh fluid in.

Also, what kind of pads did you get? If you got some high performance aftermarket ones, your braking may suck because they're not being operated at an optimal temp.

[Natty]

There was always plenty of fluid, so I don't think any got sucked in. I may rebleed anyways.
The rotors are OEM and the pads are KVR. The pads do need to be heated up, but even then they aren't so hot. They are performance, but not like Hawks or anything.

[skatanic28]

what kind of kvr's?

also.....did you properly bed the pads to the rotors? that seems to have made a big difference once i started doing it.

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

[zero.counter]

This problems is air in the system. Bleed and the squishyness/almost hitting aschoolbus at a stop sign unless slow from about 200 feet prior will desist. Autozone carried a nice bleeder kit for $5, think about it.

[Natty]

Would it matter that the pads sat in my closet for 2.5 years? They were in the original packaging and the closet was completely dry and at room temperature the whole time.

[zero.counter]

Originally Posted by Natty

Would it matter that the pads sat in my closet for 2.5 years? They were in the original packaging and the closet was completely dry and at room temperature the whole time.

No, it would not matter. Look into checking for air in the system.

[ultraDorksGarage]

if u didnt open the system and introduce air into it there is no need to bleed.

it sounds like he just pushed back pots and put new pads. if so, no need to bleed.

if u changed pads but didnt cut rotors it will take a longer period to bed pads in and in fact the might never meet full potential. if u had uneven rotor wear, the pot will not push pad down for full contact, instead u will have uneven pad contact force.

ALSO....all oem rotors have a min. thickness spec stamped on rotor, if your rotor goes under this thickness, your caliper will become less effective. this is really important.

edit: nvm i notice u said new rotors

[Natty]

Originally Posted by zero.counter

No, it would not matter. Look into checking for air in the system.

Yeah, looks like I'll be picking up some speed bleeders in the future.
I did open the cap on the master cylinder so the fluid could have absorbed air, but I don't think air bubbles are in the line.

[zero.counter]

Originally Posted by ultraDorksGarage

if u didnt open the system and introduce air into it there is no need to bleed.

it sounds like he just pushed back pots and put new pads. if so, no need to bleed.

Process of elimination would suggest he head in that direction given the problems he is experiencing and the solutions taken to correct the problem. Since there were new rotors (as you saw towards the end), and pads, the piston should have popped out by now, unless he pressed the fron pistons too far in or if he disconnected the calipers to put the pads on (which I have seen done for some reason or another). And if the world were perfect for him, he would have driven away problem free. But that is not the case, so his next step would be to check for air...

[ultraDorksGarage]

Originally Posted by zero.counter

Process of elimination would suggest he head in that direction given the problems he is experiencing and the solutions taken to correct the problem. Since there were new rotors (as you saw towards the end), and pads, the piston should have popped out by now, unless he pressed the fron pistons too far in or if he disconnected the calipers to put the pads on (which I have seen done for some reason or another). And if the world were perfect for him, he would have driven away problem free. But that is not the case, so his next step would be to check for air...

lol, okay...

of all the years as a mechanic, ive never introduced air into a brake system by opening a MC cap and pushing the pots in, but like u said uve seen it, so u might as well try it. if brake feel is bad then there is prolly air, but whatever...

id lean more to proper bedding. most carbon based bads need some smearing to be effective.

[slivia-junkie]

if no air got into the system i would guess you got dirt or grease on the rotors or pads. break cleaner or just wait for the dirt to work off.

[skatanic28]

Originally Posted by ultraDorksGarage

lol, okay...

of all the years as a mechanic, ive never introduced air into a brake system by opening a MC cap and pushing the pots in, but like u said uve seen it, so u might as well try it. if brake feel is bad then there is prolly air, but whatever...

id lean more to proper bedding. most carbon based bads need some smearing to be effective.

yeah, i dont really see how air could have gotten into the system either. provided you bled them properly last time you changed everything out, it should be just bedding them.
speed bleeders do make everything a ton easier though. pick up some of those and some fresh fluid and see how it works out. you may just have some moisture in the system as well.

[SlowCoupe]

some new rotors have like a grease film over them to prevent from rust...you should always spray with brake cleaner when installing new rotors

[aznpoopy]

things you should always do with a brake job imo:

1. bleed the brakes. it may or may not be your problem, but its just good maintenance in general.
2. bed the brakes. take it onto a deserted road. get up to 50 or so and slam on the brakes till your at a slow roll. do it again like 3 or 4 times. make sure your windows are closed. breathing in brake dust = not fun. after that let them cool down.

after that your brakes should feel normal, at least. if not, time to start checking the brake system. or maybe the pads are crap. good luck with your issue anyway.

[Stock-S13]

You have it all wrong, this is the worst approach when setting in new pads.

If i remember correctly its that you must simulate daily driving situations. In fact I think on my Axxis box it said to not exceed 35MPH and come to a slow and consistant stop with apporpriate pedal modulation. Slamming on the barkes is a horrible idea in my opinion. I can't recall what my Hawks procedure is, but that is insignifigcant as they were used.

But I agree Bleeding brakes is always a good idea, that brake fluis in your system is probably years old and sounds like you have negelected the most inportant system IMO on your car. Do yourself a favor buy speed bleeders and get to work.

Question for you, do you know how to diagnose warped rotors?

Originally Posted by aznpoopy

things you should always do with a brake job imo:

1. bleed the brakes. it may or may not be your problem, but its just good maintenance in general.
2. bed the brakes. take it onto a deserted road. get up to 50 or so and slam on the brakes till your at a slow roll. do it again like 3 or 4 times. make sure your windows are closed. breathing in brake dust = not fun. after that let them cool down.

after that your brakes should feel normal, at least. if not, time to start checking the brake system. or maybe the pads are crap. good luck with your issue anyway.

[aznpoopy]

interesting.

i was advised to do this by a bunch of trackwhores who have also consitently followed this practice.

so far, it's worked fine for me. the brakes did indeed suck when i first had them. after i bedded the pads using the above method they gripped fine.

alot of other people recommend this method as well.
http://www.zeckhausen.com/bedding_in_brakes.htm
http://www.nsxprime.com/FAQ/Maintenance/brakes.htm

i kind of oversimplified the bedding process in my above post.

warped rotors = pulsation from when you are on the brakes. but that was kind of a random question. :P

[s13gonwild]

bleed your brakes

[AllenRPS13]

like most people say breeed all brakes

[9524tee]

[QUOTE=Stock-S13]You have it all wrong, this is the worst approach when setting in new pads.

If i remember correctly its that you must simulate daily driving situations. In fact I think on my Axxis box it said to not exceed 35MPH and come to a slow and consistant stop with apporpriate pedal modulation. Slamming on the barkes is a horrible idea in my opinion. I can't recall what my Hawks procedure is, but that is insignifigcant as they were used.

..... true dat .....

[SirWarrior]

Originally Posted by SlowCoupe

some new rotors have like a grease film over them to prevent from rust...you should always spray with brake cleaner when installing new rotors

I would suspect this too, as he didn't state that he did that
bleed brakes would be the second step.