Brake Problem

This is now the third time this has happened. Last night on the highway, I started to notice a fairly sharp pull to the right on my steering wheel and then I had little or no brakes when trying to slow down. This happened to me once that I had no brakes at all and took the car to my mechanic who removed the wheels and checked the system and found nothing. He put back on the wheels and there was no problem anymore.

Any ideas on what could be causing this? I'm going to take the car to Speedy today for a brake inspection.

Thanks,

AARON

1976 230.4

[stevebfl]

It sounds to me like you have a sticking caliper piston or restricted brake flex hose. The act of the brakes dragging then causes the brake fluid to boil causing reduced braking on both front wheels.

Please don't tell me that you are taking a Mercedes to a brake shop. I presume that is what a "Speedy" is. Even though they may be very competent in their trade, they very often have poor parts purchasing capabilities and they aren't used to working on 20-30 year old cars that still work. They tend to overkill everything. Not to say it won't be needed with an old car. Its just that experience is a money saver here.

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Steve Brotherton
Owner 24 bay BSC
Bosch Master, ASE master L1
26 years MB technician

[This message has been edited by stevebfl (edited 03-16-2000).]

Thanks, that's pretty much what the tech there said, but don't worry, I'm now going to call my mechanic to find out what he can do for me. It's just a matter of convenience, my mechanic is downtown and this shop is right near work.

AARON

1976 230.4

THE VALVING IN THE MASTER CYLINDERS GET DIRTY AND STICK,BRAKES DRAG,PEDAL GOES SOFT
REPLACE MASTER CYLINDER!!!
M.F.

[Benzmac]

When I do a master cylinder, I always do the flex hoses to the calipers and a flush as well.

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Benzmac:
1981 280GE SWB
1987 16V
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM

Thanks, guys. Just went to my mechanic and he found that the front right caliper was ceased up. He had the caliper rebuilt and everything seems O.K.

However, the brake light is still lit. Is this maybe an electrical thing or is the car telling me to replace the master cylinder?

AARON.

[stevebfl]

The master cylinders used between 76 and 78 had a pressure differential switch built onto the body of the cylinder. The purpose being to warn when either side was lower in pressure (failing). The switch has a single wire coming from it and originally had a small black rubber boot covering the reset button.

To reset just push the button. If the boot is missing the button looks like a 1.5mm square protrusion of about and eight of an inch. If it can't be reset or doesn't stay reset I would suspect a pressure or air problem.

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Steve Brotherton
Owner 24 bay BSC
Bosch Master, ASE master L1
26 years MB technician

Thanks so much. I just reset the system and the light has turned off. You may have saved me a lot of money!

AARON

1976 230.4