PROCUT AND NO STOP BRAKE JOBS

OHNO60 · February 1, 2007

this has been a touchy issue around here. when ever cutting rotors with the procut truck doesn't stop! often for a while. procut rep mentioned cleaning rotors, what you guys doing to resolve the "ice skating effect"

Keith Browning · February 1, 2007

The reason you get the ice skating effect is probably die to too rough of a cut for what ever reason. A rough surface means less metal to pad contact and therefore less brake effectiveness. Me and my techs have pretty much been cutting rotors on a bench lathe. Even with our brand new machine using virgin bits the rotors often end up with a really poor cut, chatter marks and roughness. One important thing about these Pro-Cut machines is many guys have forgotten that to properly cut a rotor, you need to take a fairly heavy cut with only one pass and for me, that has made the difference. Usually, I have to hold the silencer by hand and squeeze a little to keep chatter from ruining the cut.

Cleaning the rotor does help and one other important thing, are you burnishing the pads on your road tests? If I recall, it is recommended to make 4 heavy stops to heat up the lining and rotor surfaces. I have noticed that after parking the truck and letting the brakes cool afterwords, they feel perfect. For the most part, I dispatch all brake work to my team mates so I haven't done many brake jobs over the years... just the ones that get screwed up. /forums/images/%%GRAEMLIN_URL%%/shocked.gif

Torqued_Up · February 21, 2007

The reason you get the ice skating effect is probably die to too rough of a cut for what ever reason. A rough surface means less metal to pad contact and therefore less brake effectiveness.

On Exploders I have seen these cut bad whre you had to stand on the pedal just to get the truck to slow down. No stoppie but lots o smokie! Saw one truck that the rotor turned a brownish blue color. Amazing houw you can over heat the surface and not have any stopping power. scary !@#!?$!!

Mekanik · February 23, 2007

I have found that it is a bigger problem when you cut all 4 rotors with the pro cut lathe. I try really hard to avoid that situation.

After I make a good cut, I will rotate the bits to a brand new edge and make 1 final cut. But it is a shallow cut. I only turn the bits 1 incrediment. I clean the rotors with hot soapy water and then blow it off with an air gun when I'm done. I'm usally very easy on the brakes anytime I do brake work, but I will try the 4 hard stop thing.

Jim Warman · February 25, 2007

We have a procut machine only because Ford tells us we must have one. Even the SnapOn equipment rep gave up on trying to set our machine up.

We can have a rotor off the truck and half machined before you can even get the ProCut into your bay.... But enough of that....

After a brake job, following a few simple steps to "cure" the pads can save misery and comebacks.

I like to "break" the edges of the linings.... even rubbing the pads together will accomplish this - the idea is to get rid of that sharp corner on the rotor side of the pad.

Once the job is complete, drive the vehicle to ~ 30 or 40 MPH on a suitable road. Apply the brakes moderate to heavy and slow to about 10 MPH but DO NOT STOP. Drive to allow the brakes to cool a little and repeat the process at least 4 times (I usually do about 6).

After starting to do this, I don't recall having much in the way of squealing concerns.

Shallow cuts can be detrimental.... instead of just trying to clean a rotor up, aim for a finished thickness and go there.... two passes at the very most. When machining, the chips also carry heat away from the process.... shallow cuts produce little in the way of chips and that heat stays in the rotor and tool bits...

That's this old farts take on it, anyway...

HTH

Tony302600 · May 9, 2007

OUr hunter guy got us a sweet oncar brake lathe just for trucks, 220v, This thing is absolutely amazing. I will take pix. There are 2 different heights you can put it at, but its so heavy you need a engine hoist to lift it to the higher setting.