Greetings Forum Members,


One more problem I'm having with my 87 190e 2.6.
I started bleeding my brake system to flush out old brake fluid,
using a hand held vacuum bleeder
All was going well until I got to the RR caliper where I began drawing out old brake fluid and suddenly it stopped.
The caliper would no longer bleed.
Even stepping on the pedal would not push out fluid.
I removed the caliper, flex line and rigid line leading to the line junction. Nothing was clogged.
Would the ABS system have anything to do with this?
Any suggestions?
All other calipers bleed fine.


Thanks,

Knarf

__________________
72 350SL #69
73 450SL Parts Car?
78 450sl Parts Car
79 450SLC - Sold
1985 280sl
87 190E 2.6 - Donated
90 300E-Junked
97 E420

Do you still have fluid in the master cylinder, or did you manage to suck it all out with the vac pump and get some air in there?

If you don't get fluid out the line where the flex hose connects, obviously something further upstream is clogged or leaking.

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!

The ABS should not cause this problem. I have a friend with a '92 model 190E and he said he had to turn his caliper over with the bleed screw on the bottom to get it to bleed properly. His theory was that air can get trapped in the top part of the caliper with the bleed screw on the bottom (when mounted). I was not there to witness it but when he was at the house with it we never got a good flow of fluid out when the calipers were mounted (and the bleed screw was at the bottom). I'm still scratching my head over that one.

__________________
Jim

Jim's friend:
Bleed screws should be at the TOP, unless he has R/R'd his calipers and switched right and left. Will only bleed properly with bleed screw at the top of the caliper. Stevo just reported same problem 1 week ago.

Knarf:
Remove flexible hose and make sure it is not internally collapsed. Several reports of this.

FWIW. Take care.

__________________
The Golden Rule

1984 300SD (bought new, sold it in 1988, bought it back 13 yrs. later)

opps jp You are absolutely right. I meant to say the opposite of what I said. When his calipers are mounted the bleed screw is at the bottom. They were recently replaced - could they have been mounted on the wrong side?

__________________
Jim

Most definitely!!

__________________
The Golden Rule

1984 300SD (bought new, sold it in 1988, bought it back 13 yrs. later)

Sometime it is necessary to remove the bleed screw and ream out the hole in the caliper with a small wire or pick to get the rust and debris out. Also check to see if the holes in the bleed screw itself are not clogged.

I think the 190 will be 3 channel ABS. This means that separate lines go to three areas, left and right front and both rear.

If that is the case the ABS is not the reason why one caliper won't bleed. If I am wrong and the system is 4 channel it will have 4 lines out. One to each wheel and if this is the case there is a good chance you do have an ABS actuator problem.

I have had three in twenty years but the last two were in the last year. Two have been BMWs and one was an Audi. Same type Bosch ABS as MB has.

During activation of ABS the line is blocked in one stage and hooked to the pump in the other activated stage. Anywhere in those two positions fluid will not pass to the caliper. The situation can be confirmed by activating the solenoids and listening for them to work. In the ones we have had three could be heard and the one not flowing couldn't.

We originally jumped the solenoids to see if we could unstick them. Didn't happen but it did show tyhe problem when we found we could hear the good circuits applying and the bad one, not.

We fixed all of them with used actuators as they are about bulletproof. Just so I would be prepared for my first MB I bought one like on your car for $50 on ebay the other day. They are over 2 grand new. I have never paid more than $300 for the used ones though. Junkyards have no use for them, there is no market.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

I exerienced identical problem. Solution was pressure bleeding the system to evacuate air pockets. One caveat, when M/C was pressurized to 10 psi, (pressure relief?) valves at rear of expansion tank bled profusely. perhaps 5 psi is enough to accomplish the job. Please note, this solution was only employed after needlessly replacing the master cylinder due to misdiagnosis. IF UNABLE TO DRAW FLUID FROM ANY CALIPER, TRY PRESSURE BLEEDING PRIOR TO REPLACING EXPENSIVE HYDRAULIC COMPONENTS.