Help brake bleeding - 93 3.2 m104
 

I am stuck on bleeding my brakes using the 'family method'..my son presss the pedal...I started from my passanger rear and did not progress any further.
At first, the dirty greenish color fluid came out pretty good.
I got about half a cup.
Then I notice something is very wrong.
The fluid is dripping slower and slower with each pedal depression.
The brake reservoir level remained unchanged!?
I started the engine a few time hoping it will change something...nothing.
I think I am draining the fluid from the ABS unit.

I got no brakes...sponge pedal.

Is there a proper method to breed the brake system?
How am I going to correct this situation.

Your input will be greatly appreciated.
Thanks
Earl:confused:

has your car got ASR?

My car does not have ASR.

There are two halves to your reservoir. One half feeds the front. The other feeds the rear. It often happens that the reservoir looks to be full, but one half of it emptied when you did the bleeding. You must keep the reservoir full enough so that the fluid from the one half flows over the little dam and fills up the other half of the reservoir.

Len

I concur with Sokoloff, you bled the rear chamber dry. You'll have to start over. I top off the resevoir after every other, or every third crack of the bleeder depending on how long I leave it open (usually till the stream begins to slow). To top off the rear res do as suggested and very slowly fill to the brim, you'll think it'll over flow but it will fill the rear res.

Len and Mike....It is such a simple thing that I over looked. Thanks for your tips.
Earl

I just had the same problem with my 1990 300CE. What never got mentioned, even in the manuals, is that, for my car anyway, the reservoir for the rear brakes is at the right rear of the master reservoir and is not viewable from the fender so all you see is a full (front brakes) reservoir. I have never seen anything like this before in my 45 years of wrenching. Very frustrating for a while.
Cary Cooper

I think that every person who has a W126 has been down that road. When you look at the reservoir from the driver's side of the vehicle, it remains full. The front reservoir wraps around the drivers's side and obscures the rear reservoir.

To see the rear reservoir, you must lean over and view it from the passenger side of the vehicle.

Additionally, the rear reservoir holds very little fluid. You can easily run it dry if you press on the pedal 15 times.

That is why I always recommend topping off the reservoir after every 2-3 cracks of the bleeder screw.

Mike, that's probably going overboard..........since filling the rear reservoir is such a PITA...........IIRC you safely get about 10 pedal presses before it's near the bottom.

Additionally, due to the trapped air, it's much easier to fill it from 1/4 full to 3/4 full than from 3/4 full to the top.

With two leaking rear calipers..........at different points in time...........and a third leak on the brake hose fitting............I've probably run three quarts through that reservoir.............:o

On some days, I'd get in the vehicle...........ready to go to CT (150 mi.) and get that sickening feeling of 1/2 a brake pedal..........and I'd know that the rear reservoir was empty........yet again..........really sucks to drive that far with only one system operating.:(

What timing, I am in the process of bleeding my brakes now on my w123 240D. I have no fluid in the front reservoir but the back is full. There is only 1 cap to put fluid in and it doesn't seem to be going to the front. Do I need to practically overfill it?:confused:

Glad I saw this thread. I went back out and kept pouring in fluid. It has to get to the top before it flows into the front chamber. :D :D

Apparently, the W123 is the opposite.........you fill the rear chamber and it overflows into the front chamber............???

Which is the larger chamber..........presumably for the front brakes??

Rear chamber is bigger. On my reservoir anyway. I am calling "rear" closest to the booster. It goes to the rear brakes and passenger front. front chamber is for drivers side front. Seems weird to me.:confused:

I'll make a bet that the rear chamber is for the front brakes.

And, you cannot use the master cylinder output lines as a reference. On the W126, the front chamber of the reservoir feeds the rear chamber of the m/c and vice-versa.