Pads & Rotors recommendation - Page 2 - PeachParts Mercedes-Benz Forum

torsionbar · #16 04-09-2018, 11:57 AM

Quote:

Originally Posted by tjts1

Low quality rotors can be out of balance, out of round, warped, low quality steel can have hard and soft spots built into it, internal tension that can cause warping, even crack under normal operation. These cars are so old even very good quality parts can get found very cheaply in some times because there's very little market left for them.

^ Heavy on theory, low on practice. The fact is, even the cheapest china-made rotors available today are good quality. Kent at Mercedes Source did a test of the very cheapest no name chinese rotors against ATE and Zimmerman brand rotors on his w124. He found the cheap chicom product was *better* than Zimmerman at 1/3 the price. I'm not saying all chinese replacement parts are good (they're not) but they are apparently producing a very decent brake rotor. Kent also spotted a "made in china" label on the ATE brand rotor. So clearly the chinese are producing rotors that are good enough now for ATE to put their name on it.

Quote:

Originally Posted by tjts1

Ceramic brake pads produce low dust at the expense braking power and early fade. You are trading you safety for vanity.

Sounds like you're operating on old information. In fact, modern ceramics dissipate less heat into the caliper and hydraulic system, so they have better fade characteristics than the semi-metallic type. Ceramic pads have evolved quite a bit from when they were first introduced years ago. So much so, that ceramic pads are now OE from the factory on most makes and models of new cars today.

Simpler=Better · #17 04-09-2018, 02:00 PM

Quote:

Originally Posted by vwnate1

Actually, they (another parts site) do offer slotted and drilled brake rotors and I'm wondering if they're worth the $.......

At least one of my W123's rotors are down by close to .040" on each side and that means time for new .

? Do brands matter all that much ? it's just cast iron, non ? .

Any links to a DIY brake rotor job before I screw things up ? .

TIA,

Do the w124 spaw to vented.

I don't know if they make them, but EBC products are amazing. Expensive (Was $400 for the fronts on my heep vs $120 stock) but it stops like a 5,000lb racecar.

tjts1 · #18 04-09-2018, 02:17 PM

Quote:

Originally Posted by Simpler=Better

Do the w124 spaw to vented.

I don't know if they make them, but EBC products are amazing. Expensive (Was $400 for the fronts on my heep vs $120 stock) but it stops like a 5,000lb racecar.

Is that a good thing?

dieseldiehard · #19 04-09-2018, 08:59 PM

OK, first I'll say I am a fan of Porterfield pads.
I'd select Textars as a good pad with good stopping power and a little more dark brake dust residue. No experience with Bosch but I won't use Akebonos after an accident that was the result of needing a fast stop (driver in front decided to cram the brake and I was not fast enough to react but when I did, the ceramic pads just had no grab! It could have been the rotors being harder or something but I never liked the way those pads felt after I installed them. True, they didn't generate a lot of dust but for street use they were not "good" brakes unless warmed up.

Now, maybe this is a good place to ask for opinions on what to do about a brake caliper issue I am having on my '87 300D.
About 5 years ago I installed all new rotors (Balo) and rebuilt ATE calipers obtained from a Forum member. This was an upgrade from OE to larger pads and the calipers from an E500 were rebuilt (not sure by whom). I had to source new rear heatshields off a wagon to clear the larger vented rotors. Pads are Porterfield R4S pads.
From the moment these were installed I said this was the single best investment I made in the car, it finally stopped like it should! Not grabby but very good braking with less pedal than OE. I continued using the OE booster (I almost installed a larger double booster from a limo but stopped short of that when I found the brakes were like I wanted them. Owning two '87 300D's at that time, I always noticed the difference between OE and my upgraded brakes when I drove my wife's car.

I have been watching rotor wear on my '87 and after something like maybe 30-40K miles I noticed the L rear shows uneven wear (see foto below).
Despite the car stopping very well I finally bit the bullet and decided to investigate the issue.
When I pulled the pads on that wheel the pad on the outside of the disc is worn unevenly like a wedge, with about 25% of the pad worn on one edge and 5% on the other.

One look at the wear pattern and its obvious something is wrong, there is a lip at the outer edge of the disc but little wear towards the center.
I just swapped a caliper from a wrecked E320 donor onto the car until I sort out whats wrong with this caliper (its the same ATE brand caliper and despite having a different casting # I could measure no difference between it and the rebuilt).

Then I examined the pistons on the caliper. I never looked closely at them but I note one side has a different height across it for 180 degrees around the lip. Its obviously a machined step. One piston is a mirror image of the other.
Why would this be?
Can it be ground or filed down? (I think brake pistons are anodized aluminum aren't they?)
Or is it possible the pins were dragging on the pads or some other factor to cause uneven wear like this?
Before I use a new rotor (124-423-08-12-64 MBZ) I need to get a idea why the uneven wear as I don't want to mess up a $74 rotor

DDH

dieseldiehard · #20 04-10-2018, 07:59 PM

OK, my Duh!

I consulted someone who is more experienced than I am and learned there is a retaining plate missing from the piston. Unavailable by itself. I guess the E320 caliper will have to be permanent.
And the bleeder screw uses a 3/8" wrench. Clearly something the US rebuilder put onto it as my other calipers use a 8 or 9mm metric wrench.
DDH back to the drawing board

barry12345 · #21 04-10-2018, 09:08 PM

As I understand it the cheap rotors and perhaps even some of the better ones. Are cast in China and machined in north America.

I found it strange up here in Canada the cheap rotors where labeled made in Canada. Actually of all the cars parts we can buy. Many brake parts are cheaper up here in Canada. Over sourcing from American suppliers.

Mind you have to know where to buy. This is unusual. I pay about twenty five percent of what the local parts stores charge including two day delivery.

At the same time rebuilt calipers are now quite expensive up here. Far cheaper in America.

dieseldiehard · #22 04-10-2018, 10:46 PM

Quote:

Originally Posted by barry12345

As I understand it the cheap rotors and perhaps even some of the better ones. Are cast in China and machined in north America.

I found it strange up here in Canada the cheap rotors where labeled made in Canada. Actually of all the cars parts we can buy. Many brake parts are cheaper up here in Canada. Over sourcing from American suppliers.

Mind you have to know where to buy. This is unusual. I pay about twenty five percent of what the local parts stores charge including two day delivery.

At the same time rebuilt calipers are now quite expensive up here. Far cheaper in America.

I've not seen poor quality rotors but I don't buy them often. Last rotor I bought was OE nice to see the little tri-star logo on the fine metal surface.

As for calipers I agree the quality and prices vary a lot. Here I trust Cardone rebuilt calipers. I had a bad experience with some rebuilds bought off a well known auto chain store, they had no surface treatment and had been sand blasted so they rusted terribly.
I just checked and Summit Racing wants $48 for the caliper for a W210 chassis and the same one is listed on eBay buy it now for $103 to $127 although that includes shipping.
Most people who need their car ASAP will buy from a local reseller and get what they have to offer.

vwnate1 · #23 04-11-2018, 01:14 AM

I was flushing / bleeding the bakes on one of my W123's to - day and didn't take the wheels off so I needed a 9MM bleeder wrench or at least a cranked one.....

Off to several F.L.P.S. I went , had to go back to Pep Boys (!) to find a slightly offset 9MM box end wrench .

Wow, I never thought I'd have any troubles finding multiple sizes of bleeder wrenches .

Time to begin hitting up swap meets, pawn shops and so on, one will have *exactly* what I want and think it's worthless .

torsionbar · #24 04-11-2018, 10:13 AM

Quote:

Originally Posted by dieseldiehard

Then I examined the pistons on the caliper. I never looked closely at them but I note one side has a different height across it for 180 degrees around the lip. Its obviously a machined step. One piston is a mirror image of the other.
Why would this be?

This stepped piston surface is a design feature. It helps to even out the brake pad wear by applying more pressure to the leading (or is it the trailing?) side of a pad. Without this step, the brake pads will wear into a wedge shape. If you're rebuilding the calipers, it's important to index the piston correctly, and there is a factory tool that helps to set the angle.

Some of the four piston Brembo calipers solve this problem by using different piston sizes, so that the pressure applied to the leading edge of the pad is different from the trailing edge.

Two different piston sizes pushing on the same brake pad:

The stepped piston surface achieving the same effect with a single piston:

dieseldiehard · #25 04-11-2018, 11:58 AM

Quote:

Originally Posted by torsionbar

This stepped piston surface is a design feature. It helps to even out the brake pad wear by applying more pressure to the leading (or is it the trailing?) side of a pad. Without this step, the brake pads will wear into a wedge shape. If you're rebuilding the calipers, it's important to index the piston correctly, and there is a factory tool that helps to set the angle.

Some of the four piston Brembo calipers solve this problem by using different piston sizes, so that the pressure applied to the leading edge of the pad is different from the trailing edge.

Thanks for the 'splanation and nice fotos!
Makes sense to design the step for that reason, I am replacing the rotor today and will look at the indexing but I remember they are mirror images of each other so that would be correct since the pads are on opposite sides to account for differences in leading/trailing pressures.
But the replacement caliper has a thin metal plate with a lip on it that the "defective?" caliper doesn't have - I guess I need to take a photo to show that.
I am still suspicious that a pin might have been put in crooked somehow to keep the pad on one side from moving against the disc properly, because the pad on the other side wore evenly.