Weak brakes

[ponkotsu]

My brakes were really rough and weak. So I bought new rotors and pads. Got everything done and the brakes feel nice and smooth. Normal to moderate braking is fine. But hard stop, like panic stop, they just don't have enough power. No way I can lock up the wheels on dry pavement.

I used the "silver" pads from Advance Auto. I'm wondering if they are just crappy pads...

Probably they will get stronger as they break in, but it just doesn't seem normal. And the fact that they were weak before I changed them tells me there might be something else wrong.

What could do this? Power booster? I'm sure I bled them well, and flushed with new fluid. Everything seems to be functioning normal.

Maybe they are just weak? I remember my gen 2 explorer that I bought new had pretty weak brakes. Maybes it's just the way it is.

 

[MercuryMullet]

I have 2 97s v8s. Both of them go to the floor when you hammer the brakes. The one is an offroad truck and I have removed the ABS. That one now has a good pedal no matter what. I think its just the way the ABS works.

 

[96eb96]

I used the "silver" pads from Advance Auto. I'm wondering if they are just crappy pads...

Cheap pads are are not known for stopping distance, but the are often aggressive and eat rotors.

You may also have an internally leaking master cylinder. Does the pedal sink down after a minute?

 

[koda2000]

when you installed your new rotors, did you clean them with brake cleaner before installing the pads and driving on them?

 

[ponkotsu]

Cleaned the rotors good with brake kleen. It's not a leaking master cylinder. Pedal is nice and firm. I'm going to give these a week and if they don't get better maybe I'll return the pads for better ones. They really don't look that good. They look more like an organic than semi-metalic.

 

[1996BLKBauer]

I went with the Gold series pads from AutoZone on my Explorer, and I simply turned down my existing rotors because they where in spec. I can tell you that my braking feel, and performance increased dramatically from what was ever on there before.

A few things, did you grease the guide pins, and contact points, with actual brake grease, not anti seize. anti seize simply cannot work with braking temps. Also keep in mind that the ABS in your truck is put in there so that the brakes DON'T lock up, ABS is so that you come to a safe controlled stop. I feel that the brakes on our trucks are just good enough to stop, I mean we share a lot of components with the Ranger, which weighs much less. I know that Raybestos sells Service Grade, and a sort of Heavy use pads, which may give you the feel that you want.

 

[ponkotsu]

I went with the Gold series pads from AutoZone on my Explorer, and I simply turned down my existing rotors because they where in spec. I can tell you that my braking feel, and performance increased dramatically from what was ever on there before.

A few things, did you grease the guide pins, and contact points, with actual brake grease, not anti seize. anti seize simply cannot work with braking temps. Also keep in mind that the ABS in your truck is put in there so that the brakes DON'T lock up, ABS is so that you come to a safe controlled stop. I feel that the brakes on our trucks are just good enough to stop, I mean we share a lot of components with the Ranger, which weighs much less. I know that Raybestos sells Service Grade, and a sort of Heavy use pads, which may give you the feel that you want.

Yes, I greased everything, and checked for function. I even put in new slide pins and bolts. Actually, I am a brake engineer so know a lot about brakes (mostly motorcycle). I'm not an authority on automobile brakes though. The fact that mine are working wonderfully at low to medium stops tells me the pads are to blame. On some pad compounds the mu (coefficient of friction) drops off at higher pressures.

In therory ABS can affect stopping distance even if it's not activating. There are valves and o-rings inside that have compliance and increase pedal travel. I don't think my pedal is bottoming out though.

Long stopping distance is one thing I remember clearly from my old 2000 explorer when it was new. I one time almost got in a rear-ender on the freeway. I hit the brake but it seemed like I couldn't stop. Tires never locked up, I just didn't have enough power. The dealer put new pads in the truck for me, but I don't remember ever having another panic stop after that. I generally drive conservatively so don't need to make panic stops.

Brake stopping distance is a really important issue. I'm thinking we should create a sticky topic for brake pads.

 

[1996BLKBauer]

Yes, I greased everything, and checked for function. I even put in new slide pins and bolts. Actually, I am a brake engineer so know a lot about brakes (mostly motorcycle). I'm not an authority on automobile brakes though. The fact that mine are working wonderfully at low to medium stops tells me the pads are to blame. On some pad compounds the mu (coefficient of friction) drops off at higher pressures.

In therory ABS can affect stopping distance even if it's not activating. There are valves and o-rings inside that have compliance and increase pedal travel. I don't think my pedal is bottoming out though.

Long stopping distance is one thing I remember clearly from my old 2000 explorer when it was new. I one time almost got in a rear-ender on the freeway. I hit the brake but it seemed like I couldn't stop. Tires never locked up, I just didn't have enough power. The dealer put new pads in the truck for me, but I don't remember ever having another panic stop after that. I generally drive conservatively so don't need to make panic stops.

Brake stopping distance is a really important issue. I'm thinking we should create a sticky topic for brake pads.

There may be a possibility that there is not enough surface area to stop the mass of our vehicle quickly enough, and that lager pads, and brake rotors may help with that. Also do you have steel wheels or Aluminum wheels? That I believe will make a difference in braking distance, due to the rotating inertia wanting to keep the truck moving forward, or whatever direction you are going. When I did my brake job I replaced everything on mine, with the exception of the calipers, my braking improved a lot. Also, did you try to do a panic stop right after replacing the pads? If you did you could of glazed the pads, and that could be a reason they are not gripping well.

 

[ponkotsu]

There may be a possibility that there is not enough surface area to stop the mass of our vehicle quickly enough, and that lager pads, and brake rotors may help with that. Also do you have steel wheels or Aluminum wheels? That I believe will make a difference in braking distance, due to the rotating inertia wanting to keep the truck moving forward, or whatever direction you are going. When I did my brake job I replaced everything on mine, with the exception of the calipers, my braking improved a lot. Also, did you try to do a panic stop right after replacing the pads? If you did you could of glazed the pads, and that could be a reason they are not gripping well.

More pad area would just give you more pad life. Larger rotor would have a positive effective because you have more mechanical advantage. Wheel weight inertia does have an impact, but it's very small.

I went through a pretty good break in before I tried a hard stop. They felt weak right from the beginning. I had to apply a lot of pressure on the pedal just at idle.

They are a lot better today. There was a ton of packing oil on the new rotors. I'm starting to think I may not have cleaned them well enough.

 

[1996BLKBauer]

Good to hear, I am also glad that some of my thinking out load actually does impact braking.

 

[koda2000]

i but a set of AutoZone ceramic front pads on my '01 V8 EB. i didn't turn the rotors as they were not warped and not badly grooved. i have a theory regarding turning rotors. i figure that if they're not warped, you actually get better braking once the pad wear in and conform to the rotors, because it slightly increases the surface area. i don't know if it's still done, but back in the 80's the rotors and pads on some race cars were grooved for that reason... anyway i'm very happy with the performance of the AZ ceramic pads and i really like the fact that they don't dust up my wheels. when my '00 Mountaineer needs pads (maybe before then) i'll definitely but the same pads on it.

 

[1996BLKBauer]

i but a set of AutoZone ceramic front pads on my '01 V8 EB. i didn't turn the rotors as they were not warped and not badly grooved. i have a theory regarding turning rotors. i figure that if they're not warped, you actually get better braking once the pad wear in and conform to the rotors, because it slightly increases the surface area. i don't know if it's still done, but back in the 80's the rotors and pads on some race cars were grooved for that reason... anyway i'm very happy with the performance of the AZ ceramic pads and i really like the fact that they don't dust up my wheels. when my '00 Mountaineer needs pads (maybe before then) i'll definitely but the same pads on it.

That makes sense, but even race car brakes are not grooved, I have a feeling that the wear would be very uneven, and the pad would be much thinker to allow for the same mileage as opposed to a flat pad.

Turning rotors helps to prolong the life of the pads. It also helps true the rotors so that your don't get a pulsation in the pedal. over time, and hard braking the rotors will become uneven, and the pads will not contact the rotor all the way around, and will cause a greater braking distance.

Also, I knew I should of got the c-max pads from Autozone, everybody told that they wear down rotors quickly, and since mine were just in specifications to be turned down I decided to get as much life out of the rotors. I have to clean my rims once every two weeks other wise they are almost black, instead of chrome.