Bleeding brakes, but no pressure
 

Hi Everyone,

I removed, cleaned and re-installed the brake fluid
resevoir on my 88 300e and refilled it with dot 4.
I then had my father pump the pedal to build
pressure and bled the right rear caliper. All the time,
being careful not to let any air in the system.

But when I tried to bleed the left rear, all I got was a mixture of
bubbles and fluid. I continued to bleed it, but now
I'm not getting anything. Not fluid. Not air.

I can't seen to get any pressure in the system. I've
tried running the vehicle for a minute or two but I still
have no pressure. The pedal stays spongy.

I've tried a gravity bleed, (10 minutes ) but not a drop.

Am I doing something wrong?

I've done a search on this and nothing seems to
apply. Any insight would be appreciated.

bluebenz

You need to fill up the fluid reservoir such that the rear compartment is filled.

Resevoir is full to the top. I've been letting it gravity
bleed for the last hour and not a drop. The "!" light is on
but the resevoir is full.

Pedal is mushy.

What gives?

Reservoir has two compartments. Front compartment feeds the rear brakes. The reservoir may look full, but the fluid has to overflow into the other half to fill the other compartment.

Len

They're both full.

The rear res. if VERY DIFFICULT TO SEE. Look at the inside rear corner of the res. You should see the divider and the two levels.

The rear res. is also difficult to fill. You need to fill to near the top of the opening, then rock the res. back and forth and watch the inside rear corner to see that the rear res. fills.

This is a common problem that guys have with these cars. You THINK the res. is full, including the rear, but it's not! Then you bleed the rear res. dry and nothing happens when you try to bleed the rear brakes even though the res looks full.

Duke

Been there, done that. Make sure you are parked on level ground or nose up.

glenmore
1991 300CE
2000 C280
1990 LS400

Okay guys. I can tell you for sure that the resevoir is full.
And the problem was a pin hole in the rear brake line. It was dripping
onto the skid guard and I could not notice it right away.

But thanks for eveyones help anyways.
It is appreciated.

bluebenz,

Bleeding Brakes
 

For about $30, I made a power bleeder out of small agricultural pressure sprayer. You can purchase a factory made unit for $50-$60. When need to bleed your systen again this really saves time.