500E Master Cylinder on a 190E - PeachParts Mercedes-Benz Forum

JamesDean · #1 01-18-2008, 09:48 PM

hey everyone,

I was in the shop yesterday and I had them check my brakes and looks like my master cylinder i on its way out..evindenced by the fact that the pedal keeps sinking as i brake...

So I remembered from my list, that I had a 500E master cylinder..or so I thought, So we looked up both a 190E one and a 500E one, the 500E one is cheaper by quite a bit..bout $75.

My question is...will the 500E unit bolt up to my 190E booster?

Dave says that it not so much the booster that matters as it is the master cylinder..

I found this post on here:

"According to the "Tabellenbuch Personenwagen" from April 1991 the brake booster for 190E 2.6 and 500E both are tandem ones with 8"/9" diameter, OEM part numbers are ATE T52/4A/225-210 or Girling LSC 115. They should be identical while the 300TE has a 10" single membrane brake booster.

The master cylinder is different, the 190E 2.6 has the same as a 300TE (15/16" and 3/4") but the 500E got a larger master cylinder with 1" / 3/4".

The overall pressure in the brake line is nearly the same for 300TE and 190E 2.6 - but the 500E produces more pressure for the same weight of your foot."

Just trying to get some thoughts from you guys before I do anything...

Main thing is will the 500E mc fit the 190 booster?

HarryM · #2 01-18-2008, 10:49 PM

<< Main thing is will the 500E mc fit the 190 booster? >>

That is not the main thing. The main thing is the piston diamater, and the amount of piston travel for a given amount of pedal travel. The tension of the springs inside may also be different.

Save yourself lots of headache and get the correct part.

Harry

gsxr · #3 06-18-2008, 12:02 PM

The 500E M/C has a slightly larger piston for the front brakes, so it will move the brake bias forward. If your calipers are stock, I would not use the 500E M/C, stick with the correct M/C. Also, I believe the ports exit on opposite sides for those two cars (201.029 and 124.036), so the hydraulic lines will probably not bolt up at all.

FYI, details on the M/C & booster specs are in my brake spreadsheet:
http://www.w124performance.com/docs/mb/W124/124_brakes.xls

And, some photos of the 400E/500E booster & MC are in this thread:
http://www.peachparts.com/shopforum/showthread.php?t=209172

JamesDean · #4 06-18-2008, 02:20 PM

thanks for the reply, i keep forgetting to tie up loose threads.

I did end up using the 500E master cylinder. I would agree with you not to use it on stock braking setup. Luckily, I do not have stock. I have E420s in the front and SL600s in the rear. The m/c went in without any problems, all that had to be done was move a plug from one side to the other and bam it was in.

thanks for the replies!