on car brake lathe

[William F.]

Has anyone had real experience with truing front C2 rotor/hub on car with an on car brake lathe such as Pro Cut? Some have previously expressed concern that this might not be accurate due to rather loose set up specs for Corvette front wheel bearings.
Thanks

[Terry M.]

Re: on car brake lathe

No experience here Bill, but the loose front weel bearing specs are not an issue. All one has to do is remove the cotter and tighten (just a bit) the bearing nut for the duration of the cut. Then reset the bearing clearances when the cut is complete. At least that is the theory.

[Michael W.]

Re: on car brake lathe

From what I have learned, that particular lathe locates against the wheel mounting flange and uses it's own internal shaft and bearings as the center. It touches no other part of the car making bearing play irrelevant during the grinding operation. The play should otherwise optimized as per GM spec for car operation of course.

[Domenic T.]

Re: on car brake lathe

I think These are more for the hard to remove 4WD front discs and ones like the vette rear disc. Ones that are hard to remove.

All others are easily removed and better done off the car I would think?

DOM

[William F.]

Re: on car brake lathe

I'm really looking for someone who has actually had his rotor/hub trued with one of these on car brake lathes or who personally know of another's experience.
Thanks

[Rich W.]

Re: on car brake lathe

I have a Pro Cut 9..as far as using it on a car I have done my own 69 and several other older and newer vettes..front and rear..it is a wonderful thing..it mates the rotor with the hub on the rear and the front eliminates um..tech setup error..which is very easy to do with the centrics one uses on a amco lathes or equivalent ..the thing that many car owners run into is that most techs don't know how to cut the front rotors on these cars so your car turns into the learning curve..with the pro cut there is no learning curve, bolt it to the hub and push a button..one thing that needs to be watched is removing the calipers to do the cut..we all know the damage that can occur there..so you still need someone with some experience in working on the brakes..or have you hover all over them while the work is done..I bought the clips that hold the caliper pistons in..may be a good investment to take with you to have the job done..and also on most cars the rear needs to be jacked up as to avoid rear u joint bind..other than that its a straight foward cut..

[Ronald L.]

Re: on car brake lathe

What do these thing run?

[Rich W.]

Re: on car brake lathe

Ron..if you are asking how much$.. around 10k..

[Peter J.]

Re: on car brake lathe

Rich,
Found this on youtube sure makes it look easy in trained hands.

http://www.youtube.com/watch?v=qAOFErcUMoE

[Rich W.]

Re: on car brake lathe

Pete..if he is a trained guy for Pro Cut he should be fired! Dealerships are mandated to buy these so the time issue isn't a selling issue..who wants their car worked on by a guy who touches their car for 10 minutes and charges 200-250$?? Per axle..he double machined the rotor when he started..so now there is less metal on the rotor than there could be..and he didn't use sand paper to finish the rotor..he didn't even bring up the biggest advantage of this machine..it trues the rotor and hub as one..any brake lathe can cut to a half of a k but get one that is true to the hub everytime and you have gold! That's where the techs are removed from the process..kids really are dumb these days and if this is how most are trained in using this machine we are really in for a long day!!

[Peter J.]

Re: on car brake lathe

Bad techs are always the killer in the deal. I took two brand new rotors to the "most experienced shop" in my town to have turn and when I checked them before putting back on the car they had been turned past the minimum spec cast right in to the rotor. Being a rookie fifteen years I didn't think I should have to tell these guys about limits on lathing.
Next time I'm on a road trip to PA I might look you up for brake turning because I wouldn't have a clue who to trust around here.

[Rich W.]

Re: on car brake lathe

Some day I will write a book on how bad the car repair industry has gotten..I think trust is one thing..because someone you trust can rip you off while swearing on a bible..knowing how to do the job is the real deal..I think a giant wake up call is hitting dealerships all over the country because of this..people will pay for work do be done correctly without all the monkey business that goes on with it..I can do about any Saturday you want..just give me a couple days notice!

[Peter J.]

Re: on car brake lathe

Thanks Rich, I'd give a couple of weeks notice.
Pete

[Clem Z.]

Re: on car brake lathe

how about doing this ?? http://www.youtube.com/watch?v=I5Mj_...eature=related this is also interesting. http://www.stoptech.com/tech_info/wp...rakedisk.shtml

[Peter J.]

Re: on car brake lathe

Clem,
That is exactly how I have always checked for run out on my rotors. But I thought several years back on this board I had read "shims" were a bad thing.
Can't be that bad if NAPA is recommending and selling them.
Pete