97 Astro front brake rotors

I just pulled the rotors and calipers from my '97 Astro AWD to replace the whole thing. Took the rotors to the shop to have them turned, and was told that they didn't have the right adapter to accommodate the composite hub.

I then took the rotors next door to the garage and was told by two people - independently - that they had to be turned on the van or they would not turn true.

Back at the auto parts store the guy said that wasn't necessarily so. He said that technically, yes, you should turn them on the van so that everything is perfect, but that it is possible to get a good true job otherwise.

Does it make a huge difference? Since I have to put everything back together to drive the van to the garage to have the rotors turned I went ahead and made an appointment for two days from now to just have them do the job - it's only about $40 more than I would pay for the parts myself and I trust the shop's work - but I'd like to know how big of a deal this is.

TIA,

Karl

Reply to
Karl Perry
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Well, I can tell you that at the dealership, we don't turn the rotors on the vehicles. At least not on these vans. The day is coming when we will be doing this procedure, but this is because the Colorado trucks are designed so that taking a rotor off the front is a major job. So we will be getting an "on-vehicle" rotor turning machine.

If you can get all the rust and corrosion build-up off of the rotor surfaces (where it will mount to the brake lathe) and you also clean off the wheel bearing hub surface (where the rotor mates to when you re-install it) there should be no problem. Where it becomes a problem, is when folks don't bother cleaning these surfaces. There is no way that the rotor will spin true once it's bolted back up to the hub, if these surfaces aren't cleaned properly. The end result will be a brake pulsation down the road.

Ian

Reply to
shiden_Kai

Thanks for the inside advice. At the price I'll bve paying, it is still worth having the garage do the work, but it's nice to know that Chevy itself doesn't turn rotors on the vehicle.

Karl

Reply to
Karl Perry

What? The Colorado is going back in time? I know they used to have 'lathes' that attached to the front springs of K5's so you didn't have to pull the rotor - because it's a pain in the farking ass...

-- "Ignorance is preferable to error; and he is less remote from the truth who believes noth>

Reply to
GMC Gremlin

Ian, You mean you guys don't just use the stick on sandpaper pads they sell now to do the rotors ?

Reply to
Steve W.

Aren't those the items "as seen on TV" or something like that? We do use sandpaper discs to get a non directional finish on the rotors, but they are definitely not designed to actually machine anything.

There are a lot of weird automotive repairs floating around out there.

Ian

Reply to
shiden_Kai

We used to machine the old K-5 style of rotor. We just charged a whole lot more to do those rotors. The Colorado rotors are actually bolted to the back side of the front wheel bearings. Which means that you would have to remove the front wheel bearing and rotor assembly and then separate the rotor from the wheel bearing. You have to do this on the heavy duty 2500 trucks (old style) anyway. Which we do, and charge about double to do a brake job on them.

Supposedly, (and this info is from the tech videos that we have gotten for the Colorado trucks) removal of the front rotors is complicated by the front wheel speed sensors possibly getting damaged when removing "just" the wheel bearing assembly. So, they expect you to remove the entire spindle, wheel bearing, sensor, and rotor assembly in order to do any work to the components. I'm sure we will figure out a short cut real soon.

Ian

Reply to
shiden_Kai

Yep, I looked at them to see what was so special about them. Nothing but a hunk of self adhesive 120 grit that you stick on the new pad and hit the brakes a few times. This is supposed to "true up the rotors like a brake machine" YEAHHH RIGHT.

I use a DA after I use the lathe on most rotors (never bothered on my old dirt track car, the first time I hit the brakes all the dirt cleaned them up)

Reply to
Steve W.

I just replaced both front rotors on my 97 AWD. The rotors are so cheap now I don't bother with machining the old one, jsut toss it and replaced it. The rotors only cost $45.00CAN each. I had it on for a month now, I don't feel any different with braking compared to the more expensive one that I had bought before. So, in my opinion, the cheap rotors are fine. Nevermine machining the old one.

Reply to
Kai

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