Spongy brakes on 2012 Navion

[WI Traveler]

At 7000 miles my brakes were spongy. The dealer in Tampa, FL power bled them. Now, 2000 miles later, they are spongy again. I can push the pedal almost to the floor. Has anyone else had a similar problem?

[icarus]

Find a different service provider?

Perhaps a bad power brake booster?

Icrarus

[Aqua Puttana]

2012...

I don't know if the newer NCV3's are similar, but this was highlighted for the earlier models. Might be worth checking for vac leaks. Good luck. vic

Brakes not good. Engine power loss

http://sprinter-source.com/forum/sho...1212#post61212

[sailquik]

WI Traveler,
Here is a reprint of the Dr. A (Andy Bittenbinder) Sprinter Brake Test.
I believe it pretty much applies to all Sprinters regardless of year model.

Here's Doktor A's brake test:

Here is a reprint of my previous post that may help:

"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

I suspect that your 2012 RV brakes are actually just fine.
My 2011 170" 3500 Cargo brakes work exactly as suggested in the Dr. A Brake Test.
If you are relatively new to Sprinters and don't drive your RV all the time, chances are
the brakes are working just as MB intended them to, but you are not yet accustomed
to the different "feel" between the Sprinter and your other vehicles.
"Power Bleeding" may not be a really good idea.
Was this a Mercedes Benz Sprinter Dealer, or an RV Dealer?
To fully bleed your Sprinter based RV's brakes you need the MB SDS system to activate
the ABS/ASR module to fully flush/bleed the entire brake hydraulic system.
I've had to make a few very hard stops in my Sprinters over the years, and now that I'm
accustomed to the way the brakes work, I trust them completely. When you need to stop,
the ABS/ASR module kicks in and keeps you straight and cuts your stopping distance way
down vs conventional brakes.
Hope this helps,
Roger

[WI Traveler]

Thanks for all replies. It was the Mercedes Benz dealer in Tampa, FL. They have 2 mechanics who work on sprinters.

I have since had the MB dealer in Milwaukee, WI look at it. They ordered a new Power Booster I think he called it. Will let you know it turns out.