BTW - if I misunderstood your post and you mean that it's OK to have 1mm clearance between the rotor and LCA, with the dust shield cut away in this area.... wow. I hope you're not suggesting that as it's a terrible idea.

Another data point:

260E/300E Brake Upgrade

I uploaded CAD drawings of the rotors in question to my website:

284x22 (stock 86-92 300E size)
295x22 (early 24V and 1992 400E)
294x25 (late 24V and 93-up 400E)
300x28 (early 500E and SL320)

I couldn't attach them to the forum because of the stupid 75kb file size limit (they're about 80k each). They're located here at the top of the list:
http://www.meimann.com/images/mercedes/W124_brakes/?M=D


Note that the 284 and 300 rotors have the same depth - 38mm from the hub face. Both the 294 and 295 rotors are 44mm deep. That's 6mm difference, taking up almost the entire air gap on your original setup. You just can't use them with a 1mm air gap between LCA and rotor. Thermal expansion, wheel bearing tolerances, etc all come into play and eventually you'll get rubbing (assuming there IS a gap once you chop the splash shield away).

I'm less certain about the 190E-16 however, as I have not personally measured one. The Evo II came with the 300x28mm setup though. (notice a pattern here?) About 1-2 years ago someone posted a great photo of the 400E/E420 rotor hitting the LCA ball joint area on their 300E, but dagnabbit, I can't seem to find that thread using the 'search' feature...

I didn't find the original thread with the person who had this photo, but Chris Martens had re-posted it here, along with comments from at least 2 other people who found the 400E/E420 rotors didn't clear the lower control arm. Read the whole page:

Is Pulling Out Rear Hub A DIY Job?

So it seems that even with the thinner rotors 295x22, there is still a clearance problem with the LCA joints. I was hasty to think I could just snap on the the new calipers with a bigger set of rotors and pads and I'd be finished. I just don't want to modify my shields and/or replace all of parts in that area. So this is not a straight swap into a w124. Thanks for the great info, you saved me and my benz...

Hooked

yet another data point - FA22 did this upgrade as well, noted in this thread . He had to swap the lower control arms with the later style (93+) to make it work.

You can get the SL320 calipers & rotors and that WILL bolt on with no modifications, other than bending the stock splash shield away from the rotor (no need to buy new ones for ~$75/pair). This would be a fabulous upgrade but it's not that cheap, as the SL320 claipers are much harder to locate than the E320/E420 parts - there's just less of them out there in junkyards.

Back to your original post though, I suspect you might be more than happy with just R4-S pads and a good pressure bleed using ATE SuperBlue fluid...

I must be missing something in the details here. There's no doubt that the 400E brakes bolt onto the W201, both front and rear. As stated above, Pat has done it on his 16 valve, which uses the 300E system;, 2Phast has documented the upgrade on his late model 2.6L . . . so how can there be any debate about whether the 4 pot ATE calipers aren't a "bolt-on" upgrade for the W201?

Very simple. The debate is because the 190E-16 uses ALL the SAME suspension components as the early W124, which has been proven NOT to fit by a number of people (see links above). At this point, I'm not buying the claim that the 400E brakes fit 190E-16 models with the normal factory clearance (about 6mm from LCA to back of new rotor). Maybe they work if you cut the splash shield and end up with almost no clearance between rotor and LCA. Maybe it works with used/worn rotors or something which may have another ~1mm clearance. All other 190E's use different suspension components which apparently have more clearance. There's no question that the 400E stuff fits pretty much every other W201 - just the W201.034 is in question. Just because it works on one or two people's cars doesn't mean it will fit all of them, those one or two could have been swapped to the newer style LCA or something by a previous owner.

Also, let's not forget that there are two different "400E" calipers & rotors, although they should both have the same clearance problem, since the drawings of the rotors from Brembo (link in a prior post) show the same 44mm distance from hub face to rear of rotor.

Dave,

still talking "400E brake", great. I really appreciate your work with all that tables and datas, it's great!

That is my photo, showing my 300TE with the 22mm 400E-disk.

Some weeks ago I finaly completed the work.
Additional parts needed are:
lower control arm from a 400E or a 300E-24 (car needs an alignment after mounting new LCA)
splash shield (or you bend / cut the 300E shield)
15" rims from the above mentioned cars or larger rims to clear the caliper
wiring harness from the above mentioned cars for the "pads wear" lamp

It's a lot of work and a lot of money for parts - and I still do not have the break I'd like to have (too soft).

And I will NOT do the conversion on my 2.3-16 because after 20 years she is still in stock condition and I'll ceep her like that.

best regards,
bis denn,
Christian

1989 300TE
1984 2.3-16

__________________
improve your German - please visit my homepage :-)
Das W124-Archiv

Chris,

Congrats on completing the job! Sorry about the photo mix-up. I'm pretty sure someone else also posted a similar photo, but I can't find that one. The only reason I remember is because his post said something like "hey, these hit the ball joints, what did I do wrong?". I'm glad to hear the late style LCA works with your stock knuckle+hub. A friend of omegabenz's put the E420 brakes on his diesel 124 by using the 400E's R129 knuckle+hub, but keeping his old style LCA's. So now we know either method will work.

About the soft pedal. There are four 124.133's total in my family, and a friend just bought a 124.030. Of the five cars, three have "soft" pedals despite careful pressure bleeding. It's not really "soft" - the problem is the pedal hasto move 1-2cm before you get any braking action. Once you stomp on the pedal, it's firm, ABS engages, etc. Only my diesel and my dad's diesel have nice, tight braking action from the first part of pedal travel. I can't figure out what the difference is. I tried taking the rotors+pads off the "good" car and put them on the "bad" car, but that didn't cure it. New brake hoses didn't work either. It's not an air bubble so pressure bleeding didn't change things. I'm thinking the culprit may be the master cylinder - but my second 124 with the 'problem' got wrecked last summer, so I was never able to swap M/C's and see if that cured it. Might be worth a try if yours is original?

I do notice a significant improvement in brake feel using Porterfield R4-S pads, btw. They're a little pricey but worth it, IMO. A side effect is very low dust, and surprisingly long life. What pads are you using?

I discussed this brake upgrade with my uncle, and his view is something like this. He thinks that with the size of the new calipers, there is more volume for the brake fluid to fill in each of the 4 pistons. The original is 2 pistons, so it's designed to work with the stock master cylinder. I believe he said you would have to change the master cylinder and resevoir, along with the calipers. He may have mentioned something else, but I was already ruling out the idea of the upgrade. So to really get the full effect of these brakes, you pretty much have to replace 3/4 of all the parts involved in the braking system. Way to much work IMO. He said, if you want 400E braking performance, then get a 400E, or better yet get a 500E. Okay, $20K later, "Hey these brakes work great!" Sometimes I wonder.

GSXR, you were very helpful with the information you provided me. I almost purchased these calipers on E-bay, and I hadn't the slightest clue what I was doing. I'm glad you came in because I would have been stuck. So I feel like I owe you one.

Dave,

No problem with the mix-up. I only mentioned it to say: you are right, I took that photo while working at my car, it's true that the rotor hits the LCA.

That seems to ba a common problem with the floating calipers of the W124! Some owners have that problem from the first day (original owners) an the dealer could never fix it. I never had that problem with a W123 who has single piston fixed calipers front and rear. That is the reason, I wanted a fixed caliper setup again.

We made some testing with a friend's 190D. The pedal was awfull, lots of travel and soft but the car stopped and ABS could be engaged with a heavy foot. My friend's mother who owned the car for the first 13 years said, the brake is ok, has been like that from the first day (mother is the original owner).

Without any vacuum at the booster (engine off) the pedal was very firm after some millimeters of travel (using new pads and rotors all around).

We removed both lines at the master cylinder and blocked the plugs with two blocking srews. With both lines blocked at the M/C and engine running (full vacuum) the pedal is rock hard and has nearly no travel. So the M/C is good!

With blocked line to the front brakes and connected line to the rear brakes the pedal was still firm with a little more travel.

Adding one and later both lines to the front calipers (they split after the ABS device) lead to the former status, soft and lots of travel.

You can really see, where the travel comes from.
If you remove the front wheels and brake hard (car is jacked up and secured, engine running) you notice that the caliper is turning around the vertical axle because of the play at the guiding bolts (excuse my english, might not be the best way to express that thing).

That additional movement needs more pedal travel and so the pedal gets soft at the end.

Without vacuum you have less pressure within the system and the calipers are not moving or turning. There is no visible movement if you brake hard and the pedal feeling is good / hard.

Thank you for the hint, but the answer is NO.
I changed the master cylinder of the 300TE (got a new part from the dealer) some years ago without any improvement.
We overhauled the master cylinder of the 190D (using the ATE overhaul set), again without any improvement.
It's definitely not the M/C because with both lines blocked, only pushing the M/C itself, the pedal is rock hard and has no travel.

Both cars (190D and 300TE) have stainless steel lines of cause.

You see, we really DID some testing.

There is no porterfield in Germany, we use (OEM) ATE parts (rotors and pads) that are the best.

bis denn,
Christian

1989 300TE
1984 2.3-16

__________________
improve your German - please visit my homepage :-)
Das W124-Archiv

In general that's right. You have to make sure that the parts fit to each other.

But if you have a look into the tables of the manufacturer (or more easyly into the tables of Dave Meimann) you see that nearly all W124 have the same master cylinder with a 15/16" and 3/4" bore. That is not the problem.

Ok, that's right. But we are not selling cars here, we are talking about improvements for our cars we allready own. If you are lucky and get the parts for cheap (ebay or local wrecker) AND if you enjoy working on your car AND you know what you are doing (this is not a task for a medium DIY), it's fun. If you need to buy all parts from the dealer and have to pay a workshop to do the conversion , it's a nightmare.

bis denn,
Christian

1989 300TE
1984 2.3-16

__________________
improve your German - please visit my homepage :-)
Das W124-Archiv

Chris, wow, that's some excellent info on the pedal travel problem. I know exactly what you mean about the guide pins. I wonder if those are worn on the 3 cars we have with the excess pedal travel? I know they're good on my blue car with the firm pedal. Hmmm. Well, now I can rule out the master cylinder - thanks for the tip! If you really wanted a set of Porterfield pads, I'm sure you could buy them direct from the USA, but the cost would be a little higher due to shipping - although the current exchange rate is definitely in your favor. Next time you need pads, I'd give that a try. Last time I checked, the R4-S pads for the 4-piston calipers were $139 USD, which is about $110 EUR, I think.

Hi again,

Hey, happy to help out. The reason I've been posting so much is to help prevent someone else from doing what I did - buying a set of E320/420 calipers that don't work, and having to re-sell them. (Luckily they fit W201's so there is a decent market for them.)

Anyway, Chris is correct. The master cylinder needs to match the caliper piston sizes. And the factory put the same MC on the 4-piston setup with 278mm rears. Only the V8 models got a larger MC (and a dual-diaphragm booster). Only one person I know of felt the power assist was weak with the small MC and the big brakes (Neil V on his AMG wagon), and he swapped the 400E/500E MC+booster which cured things. I don't plan to swap the MC for my car when I put on the 500E brakes unless absolutely necessary.

The 400E is a great car, although it's brakes are a little small... upgrading to the late 500E's 320mm setup is preferable. (Euro 400E's came with the bigger brakes - go figure!) You can put the 300mm front brakes on for about $400-$450, the 278 vented rears for about $350-$400, with used calipers, new pads & rotors, and assorted hardware/paint. Not cheap, but not outrageous either.

I still think you might be pretty happy with stock brakes, stainless braided lines, and Porterfield R4-S pads all around.