[Black_Panther]

Ok, i've got an easy question for you guys.
I have one warped rotor on my daily driver. Car has about 150k miles and the rotor is warped due to some mickey mouse caliper repairs in the car's past.
Now on my parts car I have good rotors-good in the sense that they don't vibrate. But there is a fair bit of rust on their edges/center (not much on braking surface). Should I get the older rusty rotors turned and swap them on? Or throw them out and get the warped rotor turned?

BP

 

[sam o nela]

hmmm...this would be a good question for that "Potentially Longest Thread Ever...." in the lounge lol....

Well first things first, did you correct the original problem with the caliper already?? Personally...if the parts car's rotors are know to be good and havent sat for too long, get em turned and see how they look...IMO, no sense in keeping an already warped rotor around wether its been turned or not...

 

[arcinguy]

i lil rust on a rotor wont hurt anything, if you put them on it will get grinded off after you hit the brakes once or twice

 

[pnoye2]

Bad braking habits is mainly the cause of rotor warpage IMO... thickness spec (min. thickness @ .748 in thousandths of an inch) should be stamped somewhere on the rotor, get a micrometer and measure rotor thickness in several places, usually they'll shave off ~10 thousandths of an inch when they turn it. I would mic both sets and go from there... hope this helps!

 

[sam o nela]

i lil rust on a rotor wont hurt anything, if you put them on it will get grinded off after you hit the brakes once or twice

Oh yeah I totally agree--thats true for a car that has been sitting around for a few days/weeks or MAYBE months depending on the weather its been sitting in...but the longer a car has been sitting, you proabably shouldnt just take extremely rusted rotors off a parts car, throw them on yours, drive around the block a few times and call it good ...hence the reason for having them turned if they are at all suspect

 

[digger89L]

Hey ...I think brake rotor turning is HIGHLY over-rated. I've been driving disc-brake cars for more than 20 years now, and have NEVER had a set of rotors turned. And I'm picky about keeping cars in good mechanical / physical / cosmetic condition. Take my 89L sedan, for instance: 366,685 kms and still running the original brake rotors front and back. I've changed brake pads when required (and NEVER used the so-called "premium" brake pads ...always the "standard" ones) ...and I've changed the rear calipers once when the parking brake mechanism seized up.

So ...for those used rotors with a bit of rust on the edges? ...take some emery paper and clean any rust/corrosion off the rotor surface, spray them down with brake rotor cleaner ...and as long as they are within spec for thickness (spec is stamped right on the rotor) and not warped, bolt them on and use them. If it makes you feel better, clean 'em up real nice, mask off the rotor surface, and paint the rest with high-heat spray paint (engine block, or bbq paint works).

 

[Black_Panther]

i lil rust on a rotor wont hurt anything, if you put them on it will get grinded off after you hit the brakes once or twice

Thats what I thought, I know painfully little about brakes so I wanted to be sure.
Original problem with the caliper was a stripped thread that was tapped incorrectly (it had a CAT bolt in it).
I replaced the whole rotor when i replaced my pads.

Thanks for the advice guys, i'm gonna install the old rusty rotor in the morning.

BP

 

[Black_Panther]

Oh yeah I totally agree--thats true for a car that has been sitting around for a few days/weeks or MAYBE months depending on the weather its been sitting in...but the longer a car has been sitting, you proabably shouldnt just take extremely rusted rotors off a parts car, throw them on yours, drive around the block a few times and call it good ...hence the reason for having them turned if they are at all suspect

point taken, if the rusty one seems weird at all i'm gonna have it turned but I think it'll probably be ok..rust is mostly just at the edge and on the inside of the vents...places it can fly off easy lol

BP

 

[johnny3]

They have to be machined "in place" unless you want to strip the knuckle down & remove the disc.Call around & find a brake shop that has a inplace brake lathe.

 

[digger89L]

Incorrect. The procedure you describe may apply to other makes of vehicles, but the rotors on the G1 Legend remove quite easily ....and do not require you to "strip the knuckle down". You make scrap a few knuckles in the process ....but no stripping required!

 

[Johnny2]

Got them mixed in with my Vigor, sorry, also Accords.

 

[john bigonion]

This is what I do, first I select a pattern to drill the rotors, according to the amount of vanes. Then after cross drilling the rotors I clean them and paint them with a good exhaust primer, after drying I paint them with the exhaust paint and bake them at 450 degrees for 4 or 5 hours. When I paint them I also paint the inside of the vanes. After baking and cooling, I lightly resuface them to get the paint off the braking surface. So far my rotors are straight and true, no rust, just brake dust and stop awesome. Also never, NEVER over torque the lug nuts, if you do, you will have warped rotors soon! Book says 80lbs, I go to 88lbs, have done so for years with no problems.

 

[Black_Panther]

Ok Follow up
Took off the warped rotor this morning and swapped on the rusty one-a rotor that has basically sat for about 2 years. I wire brushed it a little bit.
braking is smooth, the rusted rotor is working perfectly; a lot of the rust on the surface is now gone. Rotor doesn't seem to be much hotter than the one on the other side. I bled both sides but not the back.

BP

 

[digger89L]

Sorry ..us old-timers forgot to mention that you don't actually have to "remove" the caliper completely ...thus not opening up the brake lines, and requiring a bleed to clear air from the lines. Now that you've done that, you may have to bleed a bit more: the wheels are supposed to be bled diagonally ...front left, rear right ....front right, rear left.

 

[Black_Panther]

How would you replace the rotor without taking off the caliper? I didn't disconnect it from the lines, i just unmounted it but had to compress it because this rotor is probably 3mm thicker
I do realize the brakes are supposed to be bled in order..i'm just lazy I'll get to it eventually

BP

 

[digger89L]

...I meant you didn't have to remove it completely (ie: disconnect the brake line) ...you just remove it, and hang it up while working on the rotor. Compressing the piston in the caliper will not necessitate bleeding the brakes ...all that does is force the fluid back into the reservoir.

 

[jmm67]

Hey ...I think brake rotor turning is HIGHLY over-rated. I've been driving disc-brake cars for more than 20 years now, and have NEVER had a set of rotors turned. And I'm picky about keeping cars in good mechanical / physical / cosmetic condition. Take my 89L sedan, for instance: 366,685 kms and still running the original brake rotors front and back. I've changed brake pads when required (and NEVER used the so-called "premium" brake pads ...always the "standard" ones)

I totally agree, never use premium pads, they have always caused bad noise problems and no better braking when I have used them. How did that push-rod adjustment work out for you digger? Is it still braking properly?

 

[digger89L]

Hey, jmm67 ...nice to hear from you again. Yeah ...it worked out GREAT!!! I tried doing the measurement thing, as recommended in the manuals ...but ended up using the "braille" method ...just kept adjusting it til it felt right ..eventually backing it right off so there was no back-pressure at all on the push-rod. Its worked perfect ever since ...thanks to you, I was saved from a potentially VERY expensive service call to the dealer!!

 

[jmm67]

Thats great to hear digger, I wonder how many people are running their cars with their brakes partially engaged due to the push-rod being improperly adjusted. I bet there are quite a few!

 

[pnoye2]

I wonder how many people are running their cars with their brakes partially engaged due to the push-rod being improperly adjusted. I bet there are quite a few!

Are you gentlemen reffering to the "brake booster pushrod adjustment"?? if so then I'm guilty... until my last brake job a few weeks ago, inspected vacuum booster and found it not functioning properly.

The brake pedal does not drop when the engine is running or rises after the engine stopped.

I too went by feel like digger89L did...