All brakes were done last year and have been functioning just fine.

The other day my wife mentioned that the brake pedal was to the floor when she got to the bottom of a nearby hill.

Under normal conditions, like a Stop sign or red light, it will stop OK but if I continue to push the pedal will indeed go to the floor.

Likely cause? Expensive fix?

oh, everything else "vacuum" seems to work fine: door locks, shifts ok, etc.

My guess,,,,, master cylinder., especially if you can pump the brakes and get some pressure.

Pretty easy fix, and a good time to replace the brake fluid.

If I remember correctly about a 1 hour job, including bleeding all the brakes to replace the fluid.

Make sure that you replace all the o-rings and grommets, and if I had to do it over again, I would have replaced the reservoir and the grommets that it sit's on.

Good luck,

JCD

where can i get a master cylinder rebuild kit for and 83 300sd? i called all over and everyone says there is no rebuild kit. i know there is because the places sell a rebuilt mc. any info would be appreciated.

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have no worries.....President Obama swears "If you like your gun, you can keep it

Liability is the reason there is no rebuild kit.
With the punitive judgments lately, only a total idiot would sell one.
Do not drive the car any more.
The next symptom will be NO pedal = no stopping.
Here is a link to the part on FastLane

http://catalog.eautopartscatalog.com/mercedesshop/wizard.jsp?partner=mercedesshop&year=1983&make=MB&model=300-SD-002&category=N&part=Brake+Master+Cylinder

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1985 300SD
1983 300D
1984 190D
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I have rebuilt lots of master cylinders with success. But if you can't find a kit (and I know of no souce either) the prices on Fastlane for master cylinders are reasonable--at least compared to the price for a Climate Control Unit, for example. BTW, do you have a brake cylinder hone?

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1984 300SD 326,997 miles and counting . . . No wait, my odometer is still dead

its my dads that needs the rebuild so it hasnt been driven much lately. he too has rebuilt many mcs in his life so he know how. i can get a hone

__________________
have no worries.....President Obama swears "If you like your gun, you can keep it

well then why can you buy a caliper rebuild kit? i would think this would be just as much a concern,if thats the reason

__________________
have no worries.....President Obama swears "If you like your gun, you can keep it