No it doesn't.

That is not factually correct. He has not reported symptoms of a warped or damaged rotor.

Not a bad idea.

Also not a bad idea as it may help to extend bearing life. Keep in mind that wheel bearings usually give plenty of warning when they start to go bad.

I replaced my fronts recently. They were over ten years old and functioning properly, but since I was changing calipers anyway, I went ahead and did new hoses. Same for rears that were about eight years old. I would say a five year interval is a bit soon.

True.

__________________
Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 400,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 22,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.

Well we are almost on the same page. Definitely the same library and book.

I would recommend some data to back up the two claims in question. Resurfacing rotors and replacing brake lines.

According to the books, resurface everytime. Once you have cut your own rotors, and seen (actually heard) the high and low spots and what appear to be straight rotors, you realize its actually necessary. Calipers have to come off to get rotor off. "Symptoms" of a warped rotor is how much you have to cut off. His analysis is simply the pads not bonding with the rotor. Wont happen if you cut the rotors every time. Theres no way hes warping a rotor by driving too hard in that car

They new pads are flat, the rotors are not. No matter how straight they look.

He's basically putting brand new rotors on every time they need to be resurfaced.

Hoses are rated for 5 years. Do you really want to wait until they aren't functioning correctly?

Timing belts and brakes, two areas to do correctly.

Trust me, I'm an ase certified brake mechanic.

And Im only trying to help, save money and stop buying rotors. $20 to turn em.

What books are you reading? I just checked the Haynes for '68 to '72 230, 250 and 280. It mentions machining rotors if scoring of a certain depth is present. The basic procedure is to just change pads. I also checked the Chilton manual for 74-84 coupes, sedans, and wagons. It doesn't mention machining rotors at all.

While I don't do it presently, I have worked as a professional mechanic and I too have an ASE cert in brakes. I have probably done about a thousand brake jobs and did not turn or replace rotors or drums in the majority of those. I've had one bring-back from a brake job, from a guy who wanted his parking brake adjusted differently.

If you read the OP, you'll find he hasn't said a word about replacing rotors.

Where do you get the five year figure? I just checked the periodic maintenance charts in the Haynes manual mentioned earlier and the Kawasaki factory service manual for a Ninja 650 and neither mentions periodic brake hose replacement. I'm also very well acquainted with the U.S. Navy 3M system as applied to ground vehicles. The Navy is obsessed with maintenance, yet I still haven't seen a requirement for periodic brake hose replacement.

Incidentally, new W123 rotors run about $20. In fact, the last place where I wrenched for a living specialized in German cars, had a brake lathe, and never used it. We just replaced rotors when they went bad since it saved so much time. That and some of the manufacturers' guidance is to replace rather than resurface.

__________________
Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 400,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 22,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.

If I am not getting pulsing in my pedal and the rotor is not too thin I simply change the pads. Changing the rotor automatically or turning it is a good way for the shop to make more money. Of course they justify it by saying its a safety concern, and for them it is I suppose, but for a hobbiest often its just a waste of time and money.

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Trust Tom.

Times have changed maybe. Thats what is taught in automotive school now days.

10 is less than 20.

Standard practice to save time and charge the customer more.
If you turn them just a hair they will perform better and last longer

Chilton and haynes. Reliable sources? I hate those manuals.

Even the MB service manual advises against turning rotors, as there is a risk they will end up too thin and not provide enough mass to efficiently remove the heat energy, and your braking performance is compromised.

In my book, if they are warped according to the pedal-feel and "seat of the pants" observation, they get replaced. When they get down to the service limit, they get replaced. At ~$25 to $30 per rotor, it is generally cheaper and safer in the long run to just replace them with new.

__________________
Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC

From the 123 service manual, procedure 42-220:

"Note: if during a trial run (mainly after driving around a bend) a varying pedal travel is observed, measure the laterial runout of brake disc at OD. Simultaneously, check wheel bearing end play of front wheel hugs and adjust, if required.

If the lateral runout of the brake disc is too high, displace the brake disc on the front wheel hub. Renew brake disc, if required."

My understanding of "Renew" is to replace with a new part, and "displace" means shift the clock orientation of the disc vs. the hub to see if acceptable runout can be achieved.

__________________
Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC

Lucas, you have experience and I'll bet your approach works just fine, but for us shade-tree mechanics trying our best to keep these fine machines on the road with minimal cost and lots of elbow grease, and usually without access to a lathe, replacing rather than turning is a good option. If I had a lathe and a brand-new rotor that was warped, I'd be tempted to turn it to try and save it.

__________________
Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC

Is your book the old fsm? Because that is for organic brake pads.

Out of context im not too sure what all that is a part of. But renew if required...

I'll try to explain simply

At $10 a turn ($15 a set here), it will save you money overall.

If you cut just a few thousands off each time you change pads, they will last longer.

If you don't cut them the pads will never seat. You get that wheel shake. Which is creating more heat. Which is warping them more. And you will have to cut more off, or replace them.

I said this earlier. Brakes is not an area for shade tree mechanic corner cutting.

The op asked a question about brakes and I answered.

There's been a wide array of numbers put out for cost of rotors.

They make different qualities.

I should say I buy the middle of the road for a normal car. I never buy the cheap ones.

What is interesting, the original rotors were designed for organic pads, and they advice against using ceramic or semi metallic pads with them. The rotors are too soft.

New ones are composed of a different metal and they are ok for modern pad use.

Organic pads leave a ton of dust behind. Drives me crazy. Use them on my dirt bike though.

And I'm a shade tree mechanic too. Style at least. On my own cars.

Correct me if I'm wrong, but the front rotors on a W123 are not removed by simply unbolting like a modern car. I seem to recall that the front hub has to come apart. Furthermore, proper re-assembly involves the use of a special gauge to set the play of the hub.

If so, it seems to me to be another reason for the OP not to replace or turn the rotor unless he has to - if there were symptoms of warping, or the rotor itself was getting thin - I agree with the others that the OP should measure the rotor thickness while he's there.

__________________
Charlie

---------------------------
'66 VW 1300 96K miles
'97 E300D 239K miles
'85 300D 203K miles (sold Sep 2012)

The rotor is bolted to the hub with five large allen screws.

I hear this term "Seating of the brake pads". I have no idea where that came from. I always just put them on and go. Never any problem. If the rotor is not new and has not been turned a little unevenness might exist but the pad will swiftly wear to conform to the rotor.....no worries.

If the pedal is pulsing or the rotor is too thin then I replace them with new rotors.

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Prob correct. In which case its also the proper interval to grease those bearings.

For a front bearing you can use a dial indicator. $30

You can also take a fish scale, hook it to the lug bolt, and see how many lbs it takes to turn it. Check before disassembly with the caliper off.

Or, tighten as far as you can by hand, and go another 1/8 turn.

With enough practice you can do it by feal.

And if you want to get into the shade tree mechanic, art over science, you can check bearing play and set the hub accordingly. On a buddies truck recently, 400k miles, the bearings should have been replaced. But I just ran them a little tighter.

Been checking temp on them and performing fine.

That stuff drives me crazy though. My car has all fresh bearings, pads, calipers, brake lines, etc. lol. I have a problem.