I have read how other model caliper/rotars can be installed to upgrade 300E brakes with those from more current models. In reading other forums, it appears that there may be complications due to ball joints being in the way of the upgrade.

Can anyone help with what model and years will fit the std '89 300E brake carriers without resorting to changing the A arms etc. to fit. Part numbers would be especially helpful.

Thanks.

The '93 400E uses 4 piston ATE calipers in the front, with larger ventilated rotors and is a bolt on upgrade for the 300E, which uses dual piston calipers. Making sure that the rotor/calipers clears your rims should be verified first.

400E brakes (at least the late 294x25 versions) won't fit early 124's with the M103 engine (or any diesel 124). The 400E rotor is 6mm deeper, requiring either the late lower control arms, OR using the 400E's R129 knuckle/hub. The rear brakes are a bolt-on, other than needing to cut the splash shield. Full details, with part numbers etc, are in my brake spreadsheet:

http://www.meimann.com/images/mercedes/W124_brakes/124_brakes.pdf

http://www.meimann.com/images/mercedes/W124_brakes/

__________________
Dave
Boise, ID
Check out my website photos, documents, and movies!

Ooops - forgot to answer your question. The only larger FRONT brakes that will fit an 89 300E, using your STOCK control arms, knuckle, and hub, are the early 500E and the SL320 front brakes (300x28). These may require 16" wheels for clearance, though! Part numbers are in the spreadsheet above.

Getting used calipers, new rotors, pads, etc ends up being a lot more expensive than you think - trust me, BT, DT. You may want to consider trying new stock size rotors on your 300E (ATE PowerDiscs, etc) with Porterfield R4-S pads. I did some testing and found there was very little fade after 5 back to back 80-0 stops (about 3-4 minutes between each stop). From 60-0, there was none. For most street driving, just getting the R4-S pads all around might do the trick. If you roadrace, autox, or drive at warp speeds a lot... then the bigger brakes make more sense. Otherwise they'll just get you more fade resistance from ~100mph, where most of us rarely need it, at least in the USA.

gsxr, how is it that the 400E calipers and rotors bolt onto the W201's stock suspension, particularly the 2.3-16 and 2.6L, that uses the same parts as the W124 300E? Is the lower A arm on the W124 designed/manufactured differently? Replacing the dust shields with the larger 400E units goes without saying, as does the need for the rims to clear, although the 400E did come with 15" rims.

Wern't the 500E brake system essentially a Porsche set up using Porsche calipers?

Like many other components, the brakes on German cars are outsourced . . . ATE, Brembo, Balo, etc. provided the pieces for the companies.

MTI,

Not all 201's can use the 400E brakes. I know the early 90's 2.6L work OK, and Rik documented that on his website. I don't think they'll fit the 190E-16 and I never seriously looked into any other 201's. They use a different control arm, and/or knuckle/hub, depending on the model. 6mm doesn't sound like much but when that's the total gap between rotor and LCA, it's a big deal when your new rotor is 6mm deeper!

About the 500E brakes. Porsche did some design and assembly. The original brakes were aluminum Brembos, but they made noise when the pads wore past 1/2 way, and due to customer complaints the dealers were swapping them with iron ATE calipers from the SL320 which were functionally equivalent, but heavier. Later 500's were upgraded to larger 320mm brakes from the SL600, those were ATE iron calipers, kinda heavy for their size. But there were no Porsche-specific parts... I think Porsche's brakes are made by Brembo anyway, just with the Porsche logo on them. (?)

Pat at PGA installed the 400E's on his 16 valve, so I don't believe it's an issue for that model, which also used the W124 300E brakes. Haven't heard of a W201 owner, either 2.3, 2.6 or 2.3-16 owner reporting a fittament problem.

Nope.

Early 500Es used a 4-pot aluminum bremo setup. (295mm dia)

Due to complaints about noise and vibrations, this was upgraded to a cast iron ATE 4-pot which is the same setup as on the 500SL of the time. this came about in mid-ish 93.

late 93s, 94s and Euro spec 500Es were equipped with 320mm 4-piston, cast iron ATEs sourced from the 600SL.

__________________
'94 W124.036 249/040 leder; 8.25x17 EvoIIs
'93 W124.036 199/040 leder; 8.25x17 EvoIIs, up in flames...LITERALLY!
'93 W124.036 481/040 leder; euro delivery; 8.25x17 EvoIIs
'88 R107.048 441/409 leder; Euro lights
'87 W201.034 199/040 leder; Euro lights; EvoII brakes; 8x16 EvoIs - soon: 500E rear brakes
'70 R113.044 050/526; factory alloys; Euro lights

The 400E brake setup is on the front of my '84 1902.2D. Of course this is the car I did the engine swap into but still they went on with only a minor touching problem. The inside of the left rotor would lighly scrub the lower ball joint which was cured with a little ziss wheel work to knock off the high spot. The only other addition was the change to early 124 brakes by installing the 124 knuckle assemblies on the car.
So, I started with non-vented 201 brakes.
Next to early 124 vented brakes using the complete knuckle.
Present are 400E brakes with ATE 'nuclear' and cryoed rotors.
Am now working to install PFC 328mm.X 32mm. rotors with hats and Panoz calipers. This will put the 400E setup on the market when finished.

Tobias MB
190/5.8

I'm trying to decide whether or not to attempt an install of the 4 pot calipers on my 300e. I was under the impression that it's a simple pad and rotor swap along with the calipers. Then, if I want better performance all I need is steel braided lines. Now I'm getting the impression I need to replace Hubs and Knuckles. Sorry, I'm really new at this but I don't want to get in over my head. The calipers are $200. From the sounds of it, Calipers, Rotors, Pads, Lines, and possible Hub/Knuckles is going to be between $500-$800. Is it worth it for a 300e? Especially if this is just a street application? I need some expert advice please. Thanks.

Hooked.

Hooked,

Details are elsewhere in this thread, and in a couple of other threads - use the search feature. Some basic answers for you are:


1) For better performance, try stock everything but with Porterfield R4-S pads all around. (I'm running this setup now and it's very impressive for street use.)

2) Stainless lines give you very little difference in pedal feel, but they look cool, and your old rubber lines are probably due to be replaced anyway. Order these from StopTech, they are the ONLY vendor I know of which include clear vinyl protection on the lines for W124.

3) If you are engaging the ABS easily, fatter & stickier tires will make a big difference. If ABS is not engaging, the brakes are the weak link. No point in installing bigger brakes if you have stock wheels & tires!

4) Some 4-pot calipers are a direct swap, others need either the knuckle+hub, OR lower control arm swapped. Read the threads more carefully. Short answer - only the 300x28mm (SL320) calipers will bolt up to your stock knuckle, hub, and LCA.

5) For normal street use and stopping from speeds below ~80mph, the R4-S pads & stock rotors should be adequate. I can do about 5 back to back 80-0 stops with very little fade with that setup. For autox use, hard-core street use, or high-speed stopping (100+), then it's time to consider upgrading the rotors all around. If you upgrade the fronts, you really should do the rears as well to keep things balanced. Rears are easier, you need the 278x24 from a V8 W124, pretty common & cheap (but still ~$350 for used calipers, new rotors, and new R4-S pads - a little less than the 300mm fronts will cost.)

6) The 294mm brakes from an E320 or E420 are only an affordable option if you have access to the donor car and can get the knuckle+hub, or LCA's, really cheap (or free). It's more work to install, and the LCA replacement will require a spring compressor ($100 rental) AND an alignment when you're done.

7) For all new rotors, 4 used calipers, new R4-S pads, stainless lines, etc... the cost will end up in the $750-$1000 area. Trying a set of R4-S pads with your stock setup is only about $200.

__________________
Dave
Boise, ID
Check out my website photos, documents, and movies!

Contrary to what I have read to this point, the 400E - 4-POT calipers are a DIRECT SWAP onto the 300E (W124) 124.030 chassis ranges from 1986 - 1992.

They are also a direct swap onto the 190E 2.3-16, as I have done the swap to that chassis 3 times thus far. It will work on ANY (W201) that utilizes ABS, which is mid year 1985. By direct swap, meaning they will bolt right on to the carrier or knuckle if you will. The rotor & pads need to be upgraded & that is pretty obvious, wouldn't you all agree...? Once you pull the 19mm bolts from the back of the caliper & slam the new calipers on you will see exactly what I mean. Yes, you can use your original caliper bolts from either the (W201) or (W124), just remember to use a bit of loc tite

Clearance of the dust shield on the lower portion where the ball-joint is on the control arm may be your only issue. You can upgrade to the 400E/E320/E420 dust shield or just cut away a small un-noticeable portion. This same caliper is used on the later 1994 - 1995 E320 (W124.052) & fits with no problem.

But to say or even assume that the calipers are not a direct fit for ANY (W124) chassis is ridiculous. The only brake modification that requires any sort of knuckle/hub/carrier modifications are the installation of the 500SL/600SL (R129) chassis brake. Which you need to swap the knuckle/spindle & the hub assembly.

__________________
1994 E500 (MY SUNDAY DRIVER)
1993 190E SPORTLINE LE W/ M104 SWAP
1997 C230
2002 ML320
2000 BMW 528I (WIFEY'S CAR)

"Excuses are crutches for the unfounded."

Sorry, Pat, but you are wrong. The caliper bolts up fine to a W124, yes, but the 294x25mm rotor sits too close to the ball joint. Stock, there is 6-7mm clearance (air gap) betwen these (and the dust shield is in the middle taking up about 1mm of that). The 294x25 rotor sits 6mm deeper and takes away all that clearance. Trust me. BT, DT, have the photos to prove it. They don't work. I had bought a full setup from a 1994 E420 and had to sell them to someone with a W201.

Perhaps the early 4-pot 295x22 rotors fit - I have not measured those. But that seemed like less of an upgrade from 284x22, IMO. If you study the EPC, or my brake upgrade spreadsheet, you'll note that EVERY factory fitment of 294x25 rotors has either the different LCA, or a different knuckle/hub.

The W201 has a different knuckle/hub etc and the E420 stuff fits fine except (maybe) on the 16v model (not sure on that - may fit OK.)