Odds and Ends - PeachParts Mercedes-Benz Forum

Adriel · #1 11-17-2013, 12:37 AM

Got the Mercedes on the road!

Thank you to those who helped!

So exhausted! Too exhausted to post pictures... Will update when rested. For now, like to get a couple things addressed.

First issue was the the throttle linkage at the arc adjustment. Just pushed all the way to the driver's side for now. Figure the specification is in the manual, but any tricks that I should know?

Second, got a major vacuum leak, but all the lines are hooked up. Is there supposed to be a seal between the brake booster and the master cylinder? Don't recall there being one, but all I can think of...

Third, any reason not to drive with a major vacuum leak? I don't mind it shifting hard, just don't want to do damage...

whunter · #2 11-17-2013, 12:44 AM

Yes, there is a CRITICAL a O-ring between the brake booster and the master cylinder.
You can lose power brake boost if the O-ring is missing.

.

Adriel · #3 11-17-2013, 12:57 AM

Quote:

Originally Posted by whunter

Yes, there is a CRITICAL a O-ring between the brake booster and the master cylinder.
You can lose power brake boost if the O-ring is missing.

.

Thank you so very much!

Well, I don't have it as I said, and brakes are fine. Wondered why a bit hard, but then haven't driven in a long time and have driven autos without power brakes.

Link?

sleepstar · #4 11-17-2013, 12:59 AM

is there a part #, or dimensions for that o-ring? i have to pull the brake booster soon to replace a sway bar bushing. i know that o-ring exists and needs care, but i've never seen dimensions or a part #

whunter · #5 11-17-2013, 01:02 AM

Quote:

Originally Posted by Adriel

Thank you so very much!

Well, I don't have it as I said, and brakes are fine. Wondered why a bit hard, but then haven't driven in a long time and have driven autos without power brakes.

Link?

My concern is flexing master cylinder open/close the leak = unpredictable variable brake application.

The O-ring is MB# 0049973245
Pelican Parts - Automotive Parts and Accessories - Porsche & BMW

.

Adriel · #6 11-17-2013, 01:07 AM

Quote:

Originally Posted by whunter

My concern is flexing master cylinder open/close the leak = unpredictable variable brake application.

The O-ring is MB# 0049973245
Pelican Parts - Automotive Parts and Accessories - Porsche & BMW

.

Thank you so very much!

Huh?

Uggg, a Mercedes part. Will have to give Tom a call as I am a member.

Adriel · #7 11-17-2013, 01:22 AM

Quote:

Originally Posted by sleepstar

is there a part #, or dimensions for that o-ring? i have to pull the brake booster soon to replace a sway bar bushing. i know that o-ring exists and needs care, but i've never seen dimensions or a part #

May I make some suggestions?

If you do not already have a set of extensions, buy a set. Ditto with a universal joint. Craftsman makes a very nice set that has extensions, universal joints, and adapters; saved me many a time! You will need a socket, then joint, then at least a 6" if not also an aditional 3", extension, preferably 3/8" drive so nice and thin. You will have to unplug the cruise control. Hopefully you have small thin hands to help guide this contraption to the top left nut. Absolute pain to get at, especially when putting the nuts back on! I bent the bracket slightly to gain just enough space. Getting the booster back in will also be a pain. Get the nuts just started, then install the cotter pin and clip. The clip might put up a fight. Put the pin in from the left so you have space to get the clip in. Wiggle until the pin goes through.

B.T.W., don't need to remove the master cylinder!

If you are replacing the anti-sway bar bushings, are your U.C.A. bushings and ball joints good? If not, make the bushing job much easier. Can give you tips on that too!

BillGrissom · #8 11-17-2013, 01:35 AM

I used a regular round cross-section O-ring (from a Harbor Freight kit) with a rebuilt MC because the square one that came with it seemed a bit too thin to seal well.

It seems many 1990+ cars have a vacuum seal between the MC and booster. That allows the booster to be much thinner. In 60's U.S. cars, there is an inner bellows around the brake rod to make the seal. The disadvantage of the design in our cars is that a leak past the MC cylinder sucks brake fluid inside the booster, rather than just running down the firewall. I use DOT 5, so less concern with what the fluid will do.

Adriel · #9 11-17-2013, 01:48 AM

Quote:

Originally Posted by BillGrissom

I used a regular round cross-section O-ring (from a Harbor Freight kit) with a rebuilt MC because the square one that came with it seemed a bit too thin to seal well.

It seems many 1990+ cars have a vacuum seal between the MC and booster. That allows the booster to be much thinner. In 60's U.S. cars, there is an inner bellows around the brake rod to make the seal. The disadvantage of the design in our cars is that a leak past the MC cylinder sucks brake fluid inside the booster, rather than just running down the firewall. I use DOT 5, so less concern with what the fluid will do.

Thank you so very much for the reply!

What kit?

sleepstar · #10 11-17-2013, 10:04 PM

curious, are you saying that you removed the brake booster with the MC still attached? everything i've read about doing the sway bay job says to pull the MC from the booster, push it aside and then lift the booster out

Quote:

Originally Posted by Adriel

May I make some suggestions?

If you do not already have a set of extensions, buy a set. Ditto with a universal joint. Craftsman makes a very nice set that has extensions, universal joints, and adapters; saved me many a time! You will need a socket, then joint, then at least a 6" if not also an aditional 3", extension, preferably 3/8" drive so nice and thin. You will have to unplug the cruise control. Hopefully you have small thin hands to help guide this contraption to the top left nut. Absolute pain to get at, especially when putting the nuts back on! I bent the bracket slightly to gain just enough space. Getting the booster back in will also be a pain. Get the nuts just started, then install the cotter pin and clip. The clip might put up a fight. Put the pin in from the left so you have space to get the clip in. Wiggle until the pin goes through.

B.T.W., don't need to remove the master cylinder!

If you are replacing the anti-sway bar bushings, are your U.C.A. bushings and ball joints good? If not, make the bushing job much easier. Can give you tips on that too!

Adriel · #11 11-17-2013, 11:44 PM

Quote:

Originally Posted by sleepstar

curious, are you saying that you removed the brake booster with the MC still attached? everything i've read about doing the sway bay job says to pull the MC from the booster, push it aside and then lift the booster out

I mean the latter. What I read is the master cylinder had to be pulled entirely which I couldn't do. I mean, I don't have a spare reservoir cap to make a brake bleeder, so couldn't open the system.