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bluedog225
01-02-2019, 09:02 PM
I'm thinking about replacing my brake pads on my Jeep. About 50,000 miles. Do you guys who do you own brakes buy a special caliper to get around the lip on the rotor or can I take it with a couple of washers and just subtract? New rotors are cheap enough now that I'd like to avoid $50 on a specialty tool. Thanks Tom

Garret
01-02-2019, 09:18 PM
If the lip on the rotor is at all substantial (> 1/16") - replace the rotors. Never heard of a special caliper to deal with worn rotors - nor do I understand how they could, but rotors are cheaper than calipers any day.

I would never, ever add washers to a caliper - dangerous!

bluedog225
01-02-2019, 09:26 PM
Sorry. I meant a rotor dial caliper for measuring rotor thickness. Something like this:

https://www.amazon.com/Anytime-Tools-Caliper-Electronic-Micrometer/dp/B006Y1OWKS/ref=mp_s_a_1_1?ie=UTF8&qid=1546482262&sr=8-1&pi=AC_SX236_SY340_FMwebp_QL65&keywords=rotor+caliper&dpPl=1&dpID=41MaxP%2Bq9ML&ref=plSrch

Garret
01-02-2019, 10:29 PM
Ah - much better.

The lip on the edge will tell you roughly how worn it is. If, as I said, the lip is over 1/16 or so on each side, replace 'em. You can also use a regular micrometer or calipers to measure them. Problem with regular calipers is that you are measuring the lip - not the meat of the rotor.

The lip is caused by the pads leaving a little bit, right at the edge, untouched - so the lip is the original thickness.

Canoeyawl
01-02-2019, 10:33 PM
I just use a micrometer

Mike DeHart
01-02-2019, 10:50 PM
I use a micrometer to measure the rotors. That easily reaches around the lip. But it does not measure into the grooves, if you left the pads wear completely away and scored the rotors. The min allowable rotor size is most likely stamped into the outer edge of the rotor. A wire brush should bring it right up. Replace the rotors if the measurement is near the min spec, measured on smooth surfaces. Replace the rotors if they are scored and gouged, since they will have also overherated and could be warped. If they measure OK and are smooth, take them to your local machine shop or decent parts store and have them recut. That is usually cheaper than replacing them, and is necessary for proper break-in of the new pads.

Don't put new pads on smooth worn rotors that look fine. They wear more toward the OD than toward the ID. That leaves the two faces with a trapezoidal cross section instead of parallel faces. This in turn causes the new pads to contact at the ID, overheat, not seat, and can crack the caliper in extreme cases. Also, always replace brake parts on both sides of an axle. Replace one front rotor, replace both. Replace one rear caliper, replace both. When installinfg new rotors, get a can of brake cleaner and wash the storage oil off of them before you install. I usually wet a rag with cleaner and wipe both faces. Then the same again with a clean rag.

I have seen some VERY neglected brakes. Friends have told me worse.

Nicholas Carey
01-03-2019, 12:32 AM
Easiest way is to remove the rotors, take them to your favorite auto parts-cum-machine shop of choice to have them turned (an essential part of the brake job, anyway).

They'll mic them and tell you whether than can be turned or not. If they're too thin, you come home with new rotors, all in one trip.

Ron Williamson
01-03-2019, 06:32 AM
I often buy harder brake pads (Carquest house brand)which last about as long as the rotors,then change them both.
Half the time,the calipers are stiff,too(Rustbelt,BIG lake effect weather,with a huge salt mine just down the road.)
I can never afford the time to do it twice,or wait around with car up on jackstands,while the parts store sends them out for machining.
R

Garret
01-03-2019, 07:18 AM
It may be that they still turn rotors in Texas. I don't know of a shop around here that does. Drums - yes, but not rotors. New ones are too cheap to make it worth it & thinner rotors are more likely to warp.

Peerie Maa
01-03-2019, 07:20 AM
Fascinating. Another example of two nations divided . . . .
This is a rotor, https://upload.wikimedia.org/wikipedia/commons/d/da/Puma_tail_rotor.jpg

This https://upload.wikimedia.org/wikipedia/commons/thumb/7/72/Disk_brake_dsc03682.jpg/1920px-Disk_brake_dsc03682.jpg
is a brake disk.

Paul Pless
01-03-2019, 07:20 AM
Half the time,the calipers are stiff,too(Rustbelt,BIG lake effect weather,with a huge salt mine just down the road.)the one aspect of winter in yankeeland i was and to some extent am still unprepared for - how hard salt is on cars
before moving here i never owned a rusty vehicle, not even my old british roadsters. . .

birlinn
01-03-2019, 07:23 AM
Yep- my car has disc brakes, not rotor brakes.
But then you colonials have bathrooms which don't have a bath.

Garret
01-03-2019, 07:31 AM
the one aspect of winter in yankeeland i was and to some extent am still unprepared for - how hard salt is on cars
before moving here i never owned a rusty vehicle, not even my old british roadsters. . .

70's & 80's Dodge trucks: They'd literally rust away before the warranty was done. Pintos & Mavericks as well, but Dodge trucks of that era were truly spectacular in how fast they'd get gaping holes.

Nowadays, rust hits the mechanicals as you mention: brakes, fuel lines, fuel pumps, etc. Exhaust does OK as it's mostly stainless now.

cs
01-03-2019, 07:36 AM
And speaking of brake parts.

https://scontent-atl3-1.xx.fbcdn.net/v/t1.0-9/49422412_1955885857782622_6277955113902407680_n.jp g?_nc_cat=106&_nc_ht=scontent-atl3-1.xx&oh=723fd75257e06a5e6b976e0ebd8ca129&oe=5C8E1A4D

https://scontent-atl3-1.xx.fbcdn.net/v/t1.0-9/49515752_1955885894449285_4997440395903238144_n.jp g?_nc_cat=100&_nc_ht=scontent-atl3-1.xx&oh=b0b7b40b23b2e28785f229136e0a60c3&oe=5CD87768

Chad

Paul Pless
01-03-2019, 07:38 AM
just replaced the rear calipers and rotors (discs for you nick) on the explorer due to corrosion issue
the left rear caliper would not fully release and thus accelerated wear on the pad and rotor
the right rear had not yet got to this point but was visibly pitted and corroded
never even seen or heard of such a problem before moving here

Paul Pless
01-03-2019, 07:39 AM
wife or daughter? ;)


And speaking of brake parts.

https://scontent-atl3-1.xx.fbcdn.net/v/t1.0-9/49422412_1955885857782622_6277955113902407680_n.jp g?_nc_cat=106&_nc_ht=scontent-atl3-1.xx&oh=723fd75257e06a5e6b976e0ebd8ca129&oe=5C8E1A4D

https://scontent-atl3-1.xx.fbcdn.net/v/t1.0-9/49515752_1955885894449285_4997440395903238144_n.jp g?_nc_cat=100&_nc_ht=scontent-atl3-1.xx&oh=b0b7b40b23b2e28785f229136e0a60c3&oe=5CD87768

Chad

Garret
01-03-2019, 07:43 AM
just replaced the rear calipers and rotors (discs for you nick) on the explorer due to corrosion issue
the left rear caliper would not fully release and thus accelerated wear on the pad and rotor
the right rear had not yet got to this point but was visibly pitted and corroded
never even seen or heard of such a problem before moving here

The rears are more prone because they move/do less. I've spent a lot of time on freeing up frozen rear calipers.

@ Chad - that is fugly! Gotta be a story behind them.

Peerie Maa
01-03-2019, 07:52 AM
just replaced the rear calipers and rotors (discs for you nick) on the explorer due to corrosion issue
the left rear caliper would not fully release and thus accelerated wear on the pad and rotor
the right rear had not yet got to this point but was visibly pitted and corroded
never even seen or heard of such a problem before moving here
We suffer that problem as well, both in calipers and drum brakes. It is wet weather rather than salt.

cs
01-03-2019, 08:07 AM
Neither wife nor daughter, but carpenters.

They brought our Chevy 3500 dump truck back in one day and said that it was pulling hard to the left when you hit the brakes. I drove it down to the shop and yup it had a hard pull to the left, I mean you touch the brakes and it dove left. Turns out the pictures above are the pistons that push the calipers from the right side. Apparently there were no brakes at all on the right side.

Chad

moTthediesel
01-03-2019, 09:01 AM
I haven't had a rotor/disc turned in years, they are so cheap now, we just replace them. But what to do with the old ones? They are obviously too good to just throw out. I have a huge pile of them now out behind the barn. My cars and trucks, the wife's car, the kids cars, the kids trucks, it starts to add up!

I have found they make great anchors for the shoal markers we set in our bay every year. Although the fronts from my Dodge 3500 are probably big enough to hold a moderate-sized boat, I wouldn't recommend it. They make handy stands for things too. Here is the fly-tying vise we got for my older boy this Christmas. It came with just a table clamp, but he wanted a stand.

https://lh3.googleusercontent.com/-AHike0cf8NA/XC4SC6hFL3I/AAAAAAAAMg0/3P1-GI86n1wXbCQ0jtleJll54r0nplOGQCJoC/w530-h707-n/0c999fac-ed7e-4e83-b416-1d6b7bce90e1

To make it more special for him, that actually is a rear rotor off his first car, a VW Scirocco. The rear caliper had seized on it, and it was worn to a razor edge, we still laugh about that.

The Gentleman Sawyer
01-03-2019, 10:06 AM
An I'd recommend not skimping on the rotors. Not the best place to save money, in my opinion. Good ones can save you a lot of headaches down the road.....

Ken


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