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GEARS
11-19-2009, 08:59 PM
Greetings :cheers:

I need to replace the master cylinder on my 2005 316 Sprinter.

Anyone have any suggestions or tricks of the trade?

Jon

abittenbinder
11-19-2009, 10:12 PM
Greetings :cheers:

I need to replace the master cylinder on my 2005 316 Sprinter.

Anyone have any suggestions or tricks of the trade?

Jon

Why do you believe you need to replace it? Doktor A

GEARS
11-20-2009, 02:25 AM
Why do you believe you need to replace it? Doktor A

Hi Doktor :cheers:

If I push on the brake pedal and hold it, the pedal will eventually sink to the floor.

On a side note the reservoir appears to be filled with some crazy thick brake fluid...:wtf:

ZED
11-20-2009, 03:52 AM
That means the fluid is contaminated with water. It will get dark. In extreme cases it will get thick. COMPLETELY flush the brake system and you will likely be back in business.

Altered Sprinter
11-20-2009, 04:35 AM
Please follow this linkFlushing the Brake Fluid / Brake Inspection (http://sprinter-source.com/forum/showthread.php?t=5681)
And listen to what The doctor has to say, it's not necessarily a one man job.
Richard

abittenbinder
11-20-2009, 05:48 AM
Hi Doktor :cheers:

If I push on the brake pedal and hold it, the pedal will eventually sink to the floor.

On a side note the reservoir appears to be filled with some crazy thick brake fluid...:wtf:

Try this first, here's a reprint of my spring '08 posting that may be helpful:

"I receive a lot of mail and phone calls on the subject of ('02-'06)
Sprinter brake pedal feel, especially a perceived "abnormal sinking
pedal".

Many first time Sprinter owners or those who drive other vehicles
(more often than their Sprinters) are alarmed by a brake pedal feel
that they are convinced is abnormal.

Here's how to tell if your Sprinter brake pedal action is "normal" OR
in need of immediate service attention:

Engine running, push lightly on the brake pedal. Mushy and sinking
seemingly endlessly toward floor? This may be NORMAL.

Engage Park and handbrake. Shut off the engine and then step on brake
pedal 4 or 5 times. This releases the vacuum from the booster servo
and reservoir-you should hear a loud hiss when pressing pedal each
time until the vacuum is expended.

Engine still OFF, ALL vacuum expended, now step on brake pedal and
exert a steady force. Pedal should move a relatively short distance
(compared to before) and stop hard without further sinking- REGARDLESS
of how long you exert foot pressure. This is the TRUE test of the
brake master cylinder. If pedal slowly sinks to floor during this
test- you have a problem.

Now step on pedal again and exert steady pressure while starting
engine. With engine now running- the pedal should begin sinking
steadily toward floor. This is NORMAL and indicates the engine's
vacuum pump and the brake servo are working properly.

Take foot off the brake pedal and run the engine for a few seconds at
1500 rpm to build vacuum. Go back to idle speed, step on the brake
pedal slowly-see the difference and the much greater sink distance
compared to engine "off" and vacuum released?

Still convinced it's excessive pedal travel? Try this test-Engine
running, move Sprinter to a downward sloping driveway, place in
neutral and SLOWLY creep down hill. Gently apply brake pedal pressure
and note how little pedal travel is needed to stop and hold the
vehicle-now push harder-see how much pedal travel remains?

This long, soft, pedal travel is a normal characteristic of the
Sprinters vacuum booster design when engine is running." Doktor A

GEARS
11-20-2009, 12:48 PM
That means the fluid is contaminated with water. It will get dark. In extreme cases it will get thick. COMPLETELY flush the brake system and you will likely be back in business.

Actually the fluid is clear, looks like water but flows like honey.

GEARS
11-21-2009, 10:39 PM
don't worry, I'm stumped too.

Aqua Puttana
11-22-2009, 02:48 AM
Gears,
So all you heard was the chirping of crickets?

Were I you the first thing I would do is suck out the master cylinder and refill with the proper fluid. I believe that is DOT 4+, but verify that because my memory is somewhat lacking. If you were more motivated than I am, I suppose the better thing to do would be to MT the master cylinder, refill with proper fluid and then flush through the wheel cylinders to get all the old stuff out. Keep in mind that even doing that method of flush doesn't flush some of the anti-lock brake fluid components which need to be operated by a DRBIII dealer computer interface tool.

Based upon your comments to date, I wouldn't replace the master cylinder yet unless it seems stopping is a safety issue. Hope this does some good. AP/vic

brisbon
11-16-2018, 09:34 PM
thats what happens when silicone brake fluid is added to dot4. honey but clear