I'll try to make this brief, I have a 02 EX 4X4 LTD, have replaced the front brakes three times in the last four months (9,000 miles). After about 1200-1500 miles the fronts develop a sever pulsating when slowing from highway speeds. I first tried Hawk pads and powerslot cryo rotors, these only lasted about 800-1000 miles before pulsation returned along with a severe pull to the left. Parts supplier refunded money for parts, I replacede with stock Ford parts the next two times, both times started fine, but about 1200-1500 miles later, pulsating returns. In all cases the pads were bedded according to manufacturer specs, and slide pins replaces and fluid flushed and bled. Do I need new calipers, lines or am I missing something?ANY help is appreciated.

 

I haven't heard of anyone getting cryo treated rotors, whether from ART, Frozen Rotors, or Powerslot, and it not solve the pulsating/warped feeling caused by hot spots in the rotor.

When you bought the Powerslots, are you sure you got the cryo treated rotors? I'm not being a smart azz. I almost ordered the wrong ones once, that's why I ask. Plus, you're sure the supplier gave you cryo treated rotors, right? Were they ordered online?

Also, was it pulling to the left before? And did it stop each time you did the brakes, but then come back?

Stewart

 

Was it pulling to the left before you put in all of the improvements? Pulling, I have found, means the pads were left beyond their service life and are cutting into the rotors, the parts are not sliding as they should, or the the pistons have an issue. New pads and rotors - assuming that machining will not resurface the rotor beyond to gouge(s) - would be needed for the first issue, removal, cleaning, and lubricating the moveable parts is needed for the second one, and new calipers (I suggest that calipers be replaced in pairs.) is needed for the last.

Of course, depending on the mileage, both the number of miles and the type of miles, you may have a combination of issues.

For the pulsating......

I had the OEM rotors resurfaced a few times in an attempt to solve the issue. And it was bad enough to concern me. Not just an annoyance. The machining worked for, perhaps, 200 miles. But then the usage removed enough soft rotor material and left sufficient hard rotor material to cause the pulsating to return.

Finally I installed new chamfer drilled and slotted rotors with the pads that the rotor manufacturer provided. I believe that if a manufacturer sells an accompanying product that they may have tested them together and that would be the reason they are recommending them. I happen to buy Royalty Rotors (http://www.royaltyrotors.com/) from a company that is now out of business. Royalty is still in business. Just the company I bought them from is gone.

I did have an issue when driving through Montana when it was 23 degrees, I was doing 70 on interstate 15, and I had to apply them suddenly. I suspect that the cold weather and the heat generated by the sudden deexcelleration played a part in the pulsating. Not nearly as bad as it was prior to the rotor/pad installation. However, now that I have put a few more miles on them, the pulsating, which is really only a hint of doing so, is gone about 99% of the time.

So, I would recommend that you consider drilled rotors (Completely drilled through, not the ones that are only partially drilled through. You want the cooling fins to pull the air/heat/gases through the holes and exhaust it for complete efficiency. Now, some guys will tell you that the holes reduce braking efficiency because of the loss of surface. However, the reason that the fully drilled holes work is because the gases that build up between the pads and the rotors during use are evacuated through the holes and the pads actually contact the metal and no longer hydroplane over the rotor on the gases.)for the pulsating and the other ideas for the pulling.

I know my writing style could use improvement. But, as convoluted as it is, I hope you get the meaning from what I have said.

 

I don't think the problem is entirely with your front brakes. When you changed your brakes, did you do the back brakes?

What I am seeing on mine points to the ABS. If I change all four I get 30k-60k miles out of them without pulsation. It depends on how much I tow and how much mountain driving I do.

I have almost 200,000 miles on my EX.

The last time I did my brakes - about 15,000 miles ago - I just did the fronts.
I did this as an experiment. At about 10,000 they started pulsating.
What I have noticed though, is if I let off the brake and then reapply there is less or no pulsating.

I think it is the ABS reacting to not having good brakes on all four corners.
When I do brakes, normally I replace all four rotors, pads and slider pin sets.
I will be going through mine soon and am planning to replace all four and inspect the wheel speed sensors and run any ABS test with Autoenginuity.

I'll post results and milage after the fact.
I'm using Motorcraft parts as always.

 

Are you bedding in the pads/rotors after installation? This procedure transfers some of the pad material to the rotor as well as 'out gasses' the pad. If not done correctly, you will experience inconsistent material transfer which is usually what happens vs. having an actual rotor warp. If you think you have rotor warpage then you need to have measured the runout to see what it actually is before you replace parts. The pull to one side may be a sticking slide - where the caliper slides cleaned and lubricated at each installation?

From the Hawk web site: The only thing I would add is try to park it overnight if possible vs. just the 15 mins. to allow the system to fully cool down.


Burnishing Instructions

1. After installing new brake pads, make 6 to 10 stops from approximately 30-35 mph applying moderate pressure.
2. Make an additional 2 to 3 hard stops from approximately 40 to 45 mph.
3. DO NOT DRAG BRAKES!
4. Allow 15 minutes for brake system to cool down.
5. After step 4 your new pads are ready for use

 

Just an update to clear up any questions, The pulsating and pull were both eliminated each time brakes were done. Each time proper bedding procedures were done as well as bleeding brake system. The rears were done the first and third times and were done after a road test (pad bedding) following front brake job. As far as getting cryo rotors, I know I ordered and paid for them, but as far a knowing they sent me cryos, I can't be sure. Is there a way to tell? Any way, thanks fror all your replies, this site rocks.

 

Im wondering if your pins or slides arent bad.....It sounds to me like the opposite side as the pulling the brake isnt engaging fully if at all. Could be a bad caliper.....have you done the slide upgrade? obviously if it wasnt engaging one would be more worn than the other.....just some thoughts

 

just re-read that you got new slides. I am thinking the only thing unchanged is the calipers themselves. If you bleed the brakes and fluid comes out equally on both sides,. then im guessing the lines are good

 

Yes I did replace the slides, twice now!, and the only thing I have not changed are the calipers, lines and master cylender. Both calipers seem to be functioning fine, there is no sign of binding and they seem to move freely, I just can't shake the pulsating. I'm beginning to think maybe I got a defective set of cryo rotors and am thinking of trying another set, but I'm a little hesitant to throw more $$ at this than I already have!

 

I know for Powerslots, they say "CRYO" on them somewhere.

When you ordered the cryo treated rotors, how long did they take to have them treated then sent out to you? How long did you have to wait?

Stewart

 

I can't recall if they said "cryo" on them anywhere, but it took about a week and a half to get them.

 

same here changed caliper brackets and the problem was solved