Bleeding brakes and no fluid from valve - PeachParts Mercedes-Benz Forum

NoCalMer · #1 07-17-2009, 01:32 AM

I started to bleed my brakes and got the passenger rear done and then opened up the bleeder valve on the driver rear and nothing was flowing. Kept unscrewing it to see if I could get some fluid until it was all the way out? Not a drop.

I am going to pull the line to the caliper tomorrow but if this caliper has not been working then should I replace the rear pads due to uneven wear? What would cause this?

ah-kay · #2 07-17-2009, 02:18 AM

It happened with my 300SDL on Passenger Rear side. I asked members here and I was told you need to fill the rear chamber of the reservoir. I just filled the reservoir all the way to the brim and it solved the problem. I bled all the brakes then with no issues.

whunter · #3 07-17-2009, 02:55 AM

Quote:

Originally Posted by ah-kay

It happened with my 300SDL on Passenger Rear side.
I asked members here and I was told you need to fill the rear chamber of the reservoir.
I just filled the reservoir all the way to the brim and it solved the problem.
I bled all the brakes then with no issues.

If that does not fix the issue.

Some Facts About Brake Hoses:
#1. The average life of a brake hose is six years.
#2. Brake hoses deteriorate from the inside as well as the outside.
#3. Moisture is absorbed into brake fluid systems through brake hoses.
#4. Contaminants in brake fluid act abrasively on the inner wall of brake hoses.
#5. The brake hose reinforcing fabric deteriorates through expansion and moisture.
#6. High operating temperatures contribute to the deterioration of hoses.
#7. Brake hoses swell with age and restrict flow = no flow to caliper or trapping pressure in the caliper.
#8. Generally all brake hoses on a vehicle deteriorate at the same rate, So all hoses should be replaced if one is found to be faulty!

A failed master cylinder is also possible.

Look at this thread for other potential issues.

Brake:
Brake:

Have a great day.

tobybul · #4 07-17-2009, 09:39 AM

If the reservoir is full, I vote for a bad hose. This also happened to me recently. New hose fixed it.

tangofox007 · #5 07-17-2009, 10:24 AM

Quote:

Originally Posted by whunter

A failed master cylinder is also possible.

Considering that both rear brakes are connected to the same supply line, it would be fairly unlikely that the master cylinder is at fault.

My money is on a dry rear chamber in the reservoir.

NoCalMer · #6 07-17-2009, 10:32 AM

I kept the reservoir full the entire time as this was my first thought. I will pull the line and it sounds like some new lines are on order.

NoCalMer · #7 07-17-2009, 01:13 PM

Maybe this line went bad before the others due to more heat being close to the exhaust.

If I inspect the pads and find that this side has not been working and the other side is worn down a lot, then can I take one pad from the worn side and swap it with one pad from the non-worn side?

tangofox007 · #8 07-17-2009, 02:03 PM

Quote:

Originally Posted by NoCalMer

If I inspect the pads and find that this side has not been working and the other side is worn down a lot, then can I take one pad from the worn side and swap it with one pad from the non-worn side?

You could, but there is no upside to that course of action in the case of fixed calipers. The downside would be that the pads are mated to their respective rotors and you would be disturbing that relationship. However you slice the pie, two pads are going to be thinner than the other two.

Biodiesel300TD · #9 07-17-2009, 02:44 PM

Quote:

Originally Posted by NoCalMer

I kept the reservoir full the entire time as this was my first thought. I will pull the line and it sounds like some new lines are on order.

The reservoir on these cars has a front and rear compartment. There is a small divider inside the reservoir that creates to reservoir. Make sure you have fluid in both. The one where you pour in the fluid has to be completely full before any fluid goes into the other compartment. So look carefully. I did the same thing a while back.

NoCalMer · #10 07-19-2009, 12:28 AM

I replaced both rear rubber lines and started to bleed the rear passenger side and got nothing still. I unscrewed the bleeder valve all the way out and got nothing so I stuck a small punch in and struck brake fluid. That cleared whatever was blocking the bleeder valve flow. Got the brakes bleed good. Cut open the original driver side brake line open and at the end closest to the caliper I could barely see light through it after cutting it 2 inches long. Pushed the punch in the end and opened it up and pushed whatever was in the line out. The lines didn't look bad at all. I would of been fine running the brake lines awhile longer. They looked a lot worse on the outside after cutting them open.

So the problem seem to be something inside the caliper blocking the flow to the bleeder valve and also something in the line may have also no helped the issue. All the pads looked to be wearing evenly so both side have been working fine.

NoCalMer · #11 07-19-2009, 01:06 AM

The brakes are working well after the test drive. Also after replacing the ball joints, tie rods, and drag link it steers great. I did a front end alignment and got the steering alignment good and the toe alignment I set to 0. It should be within 1 mm. That is not bad for a front end alignment with a washer, string, tack, and tape measure. I am going to go get the alignment checked but I am sure the toe will be perfect just wondering about the caster after ball joints.