[darraghodonnell]

Hell o,
My front original discs (300mm Diameter) are definitely vented discs as there was on the original two plates and a gap in the middle.
My rears which need to be replaced are 278mm originally and to my eye look vented in that there are two plates but a less obvious gap between. Anywhere I look for a pair of ATE brake discs in 278mm (or any other brand in 278mm) they are available in solid, which makes me wonder if, although my rear original discs look vented, are they?
Does anyone know if the original are classed as solid even though there is a bit of a gap between the two plates?
Thank you for listening,
Darragh

 

[Pete S]

Vented rear discs started in 99 iirc.


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[ou1954]

Hell o,
My front original discs (300mm Diameter) are definitely vented discs as there was on the original two plates and a gap in the middle.
My rears which need to be replaced are 278mm originally and to my eye look vented in that there are two plates but a less obvious gap between. Anywhere I look for a pair of ATE brake discs in 278mm (or any other brand in 278mm) they are available in solid, which makes me wonder if, although my rear original discs look vented, are they?
Does anyone know if the original are classed as solid even though there is a bit of a gap between the two plates?
Thank you for listening,
Darragh

While on this subject, is there any reason I can't do the brake job myself? Used to do it in the olden days on domestic cars. I would do one wheel at a time.

I also understand MB brake rotors are replaced, not turned.
=============

Finally, is there a torque specification on front bearings? I understand all I need to order are rotors, pads, and maybe wear sensors. The sensor light is flickering, no idea whether it's front or year, though.

I do, so much, miss those big factory manuals . . . .

 

[cliffyk]

There is no reason you cannot DIY the pads and discs. Wear sensors usually come with new pads

The front discs can be removed/replaced without removin the hub.

There is no torque spec for the front axle nut (bearing pre-load), it should be adjusted to create 0.01 to 0.02 mm (0.0004" to 0.0008") I.e. quite little axial play.

Here are some Workshop Information System (WIS) documents:

Front pad RnR;

Rear pad RnR;

Brake discs RnR;

Compressing the caliper discs can be done without a dedicated tool however it is a whole lot easier if you have a proper tool like this one from Lisle--[ame="http://www.amazon.com/Lisle-Quick-Quad-Spreader-LIS-29100/dp/B00B3HXMNQ"]Amazon.com : Lisle Quick Quad Pad Spreader LIS-29100 : Everything [email protected]@[email protected]@http://ecx.images-amazon.com/images/I/[email protected]@[email protected]@312xijZnplL[/ame].

You may be able to borrow or rent one from a FLAPS...

 

[hotshoe]

Remember to use a piece of tubing and the bleeder screw when pushing back the caliper pistons. Don't want to push all the gunk back up the line. Good idea to do a brake fluid flush at this time while the wheels are off.

 

[ou1954]

SL500 '98 brakes overall

There is no reason you cannot DIY the pads and discs. Wear sensors usually come with new pads

The front discs can be removed/replaced without removin the hub.

There is no torque spec for the front axle nut (bearing pre-load), it should be adjusted to create 0.01 to 0.02 mm (0.0004" to 0.0008") I.e. quite little axial play.

Here are some Workshop Information System (WIS) documents:

Front pad RnR;

Rear pad RnR;

Brake discs RnR;

Compressing the caliper discs can be done without a dedicated tool however it is a whole lot easier if you have a proper tool like this one from Lisle--Amazon.com : Lisle Quick Quad Pad Spreader LIS-29100 : Everything Else.

You may be able to borrow or rent one from a FLAPS...

I'll check to see whether anyone around here has one. Only problem is that I will be doing only one wheel every day or so and they may not want me to keep the tool that long. I really need to see the thickness of the disks to see whether they need replacing. Dealer recently reported 12% remaining but I don't know whether front or back, pads or rotors. I do know that there I a thin rim showing on the fronts which means they are pretty far down.

In the olden days I used to squeeze the pads back with my fingers or a wrench, forgot which. I'll look at the references. I surely miss the old manuals. For Corvettes (Had 4) the manuals even included comments on how various parts worked. For the SL500 the CD is worthless.

PS pump kit was ordered from AZ last Friday, tracking says they are due next Saturday. UPS deal with US mail is terrible.

Thanks,

DAW

 

[ou1954]

Flushing

Remember to use a piece of tubing and the bleeder screw when pushing back the caliper pistons. Don't want to push all the gunk back up the line. Good idea to do a brake fluid flush at this time while the wheels are off.

I don't remember doing this. I do remember having to empty the reservoir as I went though. I should do this. I didn't bring my jack stands with me when we moved (Unless my kids packed them, they finished packing for me as we drove off, leaving the moving van still loading. He had to go by the warehouse to pick up things we had stored to show the house but he beat us here.)

 

[ou1954]

There is no reason you cannot DIY the pads and discs. Wear sensors usually come with new pads

The front discs can be removed/replaced without removin the hub.

There is no torque spec for the front axle nut (bearing pre-load), it should be adjusted to create 0.01 to 0.02 mm (0.0004" to 0.0008") I.e. quite little axial play.

Here are some Workshop Information System (WIS) documents:

Front pad RnR;

Rear pad RnR;

Brake discs RnR;

Compressing the caliper discs can be done without a dedicated tool however it is a whole lot easier if you have a proper tool like this one from Lisle--Amazon.com : Lisle Quick Quad Pad Spreader LIS-29100 : Everything Else.

You may be able to borrow or rent one from a FLAPS...

Got two fronts and one overall. I wonder whether I can pick up the other one by editing the URL

 

[cliffyk]

Got two fronts and one overall. I wonder whether I can pick up the other one by editing the URL

I fixed the link in the post above, I had cut an pasted the whole URL then forgot to change the filename...

Here is the parking brake shoe RnR...

 

[ou1954]

I fixed the link in the post above, I had cut an pasted the whole URL then forgot to change the filename...

Here is the parking brake shoe RnR...

Great, got it. Was there supposed to be one for the rear disks matching that for the fronts? The first two URL's in your original post were for front disks and I though there might be a matching one for the rear disks. I tried to reconstruct the URL but couldn't make one that worked.

I've seen special tools but MB takes it to the limit. Not only that, they take everything to the limit. Once, in San Diego, I went in with a known and very trivial problem. They had to first spend an hour on it, running specific diagnostic programs and processes. Forgot what it was for, but it was for my wife's new ML320 which was still in warranty. They probably got more money or met some MB rule by doing that.

On the other hand, my wife took her new car in for something like an air filter and they ran up an $800+ bill, replacing windshield wipers (which I had just replaced) and several other things. She called me, crying. I went in and they made some major cost adjustments. I later became friends with the shop manager who turned out to be a fellow SCUBA diver. We never dove together but he was very helpful.

When I got my used SL500 I had all fluids replaced, including transmission, differential, and torque converter. They said it wasn't necessary but finally did it.

Here, in OKC, I had them replace her transmission fluid, an adapter connector, and the transmission pan filter.

Now both cars have the red plastic seal missing from the transmission filler and they always write that up. I think they cost around $5.00 or so, but I don't plan to replace them.

PS seal expected Saturday, but most likely sooner since it's now in transit and has passed the first city on the route from Phoenix.

Thanks again,

DAW

 

[cliffyk]

The WIS has just the one document re: disc removal--they are romoved in the same manner...

 

[darraghodonnell]

Hi, Thanks for the replies,
I presume this guy is a benzworld member - I love his work -

P.S. what about my question - does anyone have 278mm rear discs and are they vented or do they just look vented?



kindliest regardations,
D.

 

[ou1954]

Brakes and more

Hi, Thanks for the replies,
I presume this guy is a benzworld member - I love his work -
https://www.youtube.com/watch?v=lJ8T1VqeagI

P.S. what about my question - does anyone have 278mm rear discs and are they vented or do they just look vented?

kindliest regardations,
D.

Great video, more light would have helped but when one gets to the job things should be obvious. Now, where are my jackstands?

I wonder just how much of a lip requires rotor replacement? The fronts are really bad, the rear rotors are good. no lip showing. I tend to believe that the warning light is from the front sensors.

The rear rotors are either newer of just don't wear much. In any case I'm not going to mess with the parking brake drums.

By the way, brakes are after the PS pump. Then HYDRAULICS and then the CD changer. Finally paint chip work.

 

[cliffyk]

The condition of the surface (no cracks, bad grooves, etc.) and thickness are the two major considerations if they ar OK then don't worry about the "lips" at the outer edges--the pads will wear very quickly (like the first 10 stops) to accomodate the lip, with little to no loss in brakeing power while they do.

If the lip bothers you use a mill file to file it off--again assuming the disc thickness is within serviceable limits...

 

[1mbzdoc]

Vented rear discs started in 99 iirc.


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98 with esp was the first year in usa with vented. with out esp non vented
non vented are 290mm and vented are 300mm

 

[ou1954]

Disk "lips"

The condition of the surface (no cracks, bad grooves, etc.) and thickness are the two major considerations if they ar OK then don't worry about the "lips" at the outer edges--the pads will wear very quickly (like the first 10 stops) to accomodate the lip, with little to no loss in brakeing power while they do.

If the lip bothers you use a mill file to file it off--again assuming the disc thickness is within serviceable limits...

I sort of figured that. When the time comes I will measure the thickness and see how they compare to the specs.

In California I never encountered such lips. I do remember having some disks turned (there was a law about how thick they had to be before the shop would turn them).

On one case I ended up with a throbbing brake pedal. The shop re-did them, using a new machine that did both sides at the same time. I also remember filing some rotors, forgot why, but it didn't cause a problem.

 

[1mbzdoc]

there is a minimum thickness it has to be. each rotor has the spec stamped into it. if lip is big i will chamfer the top and bottom of the pad so it will sit flat against rotor from begining or it might glaze the pad because it will have uneven press on rotor

 

[ou1954]

there is a minimum thickness it has to be. each rotor has the spec stamped into it. if lip is big i will chamfer the top and bottom of the pad so it will sit flat against rotor from begining or it might glaze the pad because it will have uneven press on rotor

Good point. Aside from that I was sort of concerned about the new pads grinding against the ridge. On the other hand the new pads might nor be any wider than the old ones so they might not touch the ridge.

In any case, I'll look for the thickness spec and see what it says.

Thanks-

 

[wlb50]

Fortunately i have kept my W124 on line documentation as my 129 is sparse - but they have a whole page devoted to minimum thickness - as for me I have simply used a fingernail as the guage - if the ridge is enough to stop your fingernail I replace the disc.

Generally for the fronts it is 3 sets of pads per disc. At least on the W124.

FWIW I thought all MB brake discs were vented - they were on the rear of the 300E - I would be surprised if they weren't on the 129 which is higher performance.

Sure aids in the cooling.

 

[ou1954]

Fortunately i have kept my W124 on line documentation as my 129 is sparse - but they have a whole page devoted to minimum thickness - as for me I have simply used a fingernail as the guage - if the ridge is enough to stop your fingernail I replace the disc.

Generally for the fronts it is 3 sets of pads per disc. At least on the W124.

FWIW I thought all MB brake discs were vented - they were on the rear of the 300E - I would be surprised if they weren't on the 129 which is higher performance.

Sure aids in the cooling.

At least 1/16". Should measure it. The warning light is bothersome and I'm pretty sure it's coming from the front wheels because it varies. The front wheels have some freedom to wobble while the rears are pretty solid.

I'll have a look after the Power Steering seal kit gets here and installed.

Thanks,

DAW