Larry, are you a computer geek? Probably one of those fastiduous UNIX admins what with the way you keep your car serviced.

;)

No pistons came with the rebuild kits. All I got were two small boxes of rubber gaskets with no instructions whatsoever. I can't remember who made the gaskets, but it was not MB. It was a famous British firm - Leyland, perhaps? I will have to dig them out and look.

I have read repeatedly that you should never separate the two halves of a caliper. Probably some seals in there that you would never be able to replace correctly without the special tools to do so. Also, I doubt if anyone would ever reccommend it just for liability reasons alone. You could get a junk one from the salvage and split it just to see what the hubbub was all about.

I only have a vague idea of what is inside a brake caliper. I know that fluid pressure goes in, and the pistons push out onto the brake pads, but how the thing works, I have no idea.

How do the caliper pistons return to their bores? Why don't the pistons stay extended when you let off the brake pedal? Anyone willing to enlighten the brake newbie?

Thanks again,

Jack
93 400e 102k

For an explanation as to how major automotive systems work, check out:

http://www.howstuffworks.com

Once inside, click on ENGINES AND AUTOMOTIVE

FYI caliper rebuild kits are available from MBZ. However, apparently they're in short supply as my dealer just snagged the last 2 in the US for me (they're in CA) and they will cost just under $20 each.

That is what I found here. My dealer said that they could not find any caliper rebuild kits. I bet that they would be glad to sell me that new caliper for $750 though!

;)

Thanks for the link to howstuffworks.com, Mike. That place is a gold mine of technical information on all kinds of stuff!

There are no replacement seals available to re-seal the calipers if you take them apart. There is fact may not be any in there, just super precision machined surfaces. Leave them alone.

You also will ruin the caliper if you hone the bore. This is not a master cylinder with a honed surface, it is precision polished and chrome plated.

So is the piston. If you damage the smooth, shiny surface of either, they won't slide, and will stick. Unless damaged, they last indefinitely -- the ones on my 220D are mostly original, and the car is almost 30 years old. I did have to replace one -- corroded piston from running rotors under minimum thickness and consequent sticking with severe overheating.

The seal retracts the piston enough that the runout in the rotor will push it back. Old seals get hard, and then the brakes drag.

Peter

I have the solution! Thanks to Mike Murrell for suggesting this.

Caliber Motors rebuilds 400e brake calipers. See below.

I feel that I could probably do this job myself, but the wife drives this car and I don't know if I can bring myself to do my first brake rebuild on it. If it were just me, I would check the emergency brake and just baby it. Since it is her, and if she broke the new Euro lights by running into something......ach, it is too sad to contemplate.

Thanks to all for the input. Check out the message below:


THE CALIPER COMES IN A REBUILT EXCHANGE PRICE IS $119.20 WITH A CORE CHARGE OF $110.00 WHICH IS REFUNDABLE UPON RETURN.ANY QUESTION YOU MAY REACH TOM HANSON @800-252-6877 X306

----- Original Message -----
From: <eoracledba@yahoo.com>
To: <POCOCK_ANAHEIM@MBRETAILER.COM>
Sent: Sunday, September 09, 2001 6:42 AM
Subject: Caliber Motors, Inc. - Parts Request


> The following client has submitted a request:
>
> Mr. Jack Silvey
> Email: eoracledba@yahoo.com
> Day Phone: No day phone number provided
> Evening Phone: No evening phone number provided
>
> Street Address: No address supplied
> City: No city supplied.
> State: TX
> Zip Code: 75028
>
> Vehicle Year: 1993
> Vehicle Make: Mercedes-Benz
> Vehicle Model: 400e
>
> Part Number, Name or Description:
> Rebuilt right front brake caliper
>
>

Good choice.

I never do brakes for anyone but family, too much liability if they don't work properly.

Caliper replacement isn't much more work than changing pads.

You might want to replace the rubber line at the same time, too -- cheap, and a new one won't go bad as soon as an old one!

Peter

Update:

Caliber called and said that the factory no longer does brake caliper rebuilds and they cannot get the part. Bummer.

Wholesale cost for one new caliper: $668. Ouch.

Lesson of the day: change your brake fluid regularly. I think that the PO did not do brake fluid service and now my calipers are rotted from the water in the old fluid.

Am waiting for pads and brake fluid from mercedesshop.com and will have a go at it myself.

I guess that this means that I have to drive the Mercedes for a while. Darn the luck!

:D