Recently bought an '82 240d and I noticed the driver's side rug was completely deteriorated underneath. I pulled it up and notice there was fluid, which I suspected was brake fluid 'cause it didn't smell. There was also what looked like paint mixed in with the rotted rug/rug foam material.

I found a few posts talking about the fact that sometimes the master (?) cylinder leaks into the car and gets under the driver's rug. I guess it sounds like that's what's happening here.

I topped up the reservoir to determine, after some time driving, if the leak still exists. When it did that, I noticed there seemed to be two sections of the reservoir - one in front and one in back, both of which have min and max lines. The front was full but the BACK portion of the reservoir was below minimum.

Why are there two such sections of the reservoir. Can anyone tell me the significance, if any, of the fact that the front part was full and the back part was very low?

thanks...Joe Z

Hello Joe Z
Here are some links that will help you understand
http://www.familycar.com/brakes.htm
http://www.mustangmonthly.com/techarticles/89378/
http://www.buckeyetriumphs.org/technical/Brakes/Theory/Theory.htm
http://subtopics.freeyellow.com/Brakes.htm
http://www.advanceautoparts.com/howtos_tips/automedia_html/ccr/CCR20020201HB/index.html?page=/howtos_tips/automedia_html/ccr/CCR20020201HB/CCR20020201HB.htm

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Thanx whunter! Odd, I never noticed two separate "reservoirs" before. Links were great.

JoeZ

Manual or auto tranny?

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Joe Z

Your clutch master cylinder is bad. Replace it . Sounds like it has been leaking for some time. brake fluid eats things up so clean out under the rugs good. do a search about bleeding the system. The procedure might sound a little strange but it works good.

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1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"

I didn't follow whunter's links, but none of them looked MB specific. So please disregard if this is duplicate information. On the W123, the opening for the back portion is a tiny hole right up near the neck of the reservoir. So you have to pour fluid in until the level is all the way up into the neck in order to fill the back section.

The supply hose for the clutch master cylinder uses a simple press fit with a rubber grommet. In mine the grommet deteriorated and allowed the hose to slip out. It was worth the peace of mind to replace the whole master cylinder.

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Thanks guys!

Peter: its a manual transmission...that significant?

Thanks Steve, Rick...I'm cleaning up all the mess under the rugs, and I'm watching to see if I'm losing any brake fluid for a few days.

best regards Joe Z

Yes, Joe:

Your clutch master cylinder or lines are leaking brake fluid -- it draws from the rear chamber of the brake master cylinder.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!