Who Else has Soft Spongy Brakes on their MB?

[Geeber]

Yes, and they do improve when pumping the pedal. 2015 MBS Forrester

[mksimmons]

Yes 2015 S

[Still Kickin]

Originally Posted by barnbnb

I'd like to do a survey on Sprinter brakes. Please only answer if you are having an issue!!! That way we can keep this short and concise and easily keep track of how many folks have problems!!!
I have seen other posts regarding this, most recently by MiataHoarder, but don't know who else on this forum has had problems.
I have had the booster and master cylinder replaced (under warranty on my 2014 24R with 5000 miles), but the brakes are still spongy and the pedal will travel all the way to the floor when depressed. I really have to stand on them hard when stopping.
I called the 800-FOR-MERCEDES number yesterday. They had a tech guy call me right back to discuss the problem, but they are unfamiliar with any issues that people are aving with the brakes. I told him I see posts about soft brakes here and other Sprinter forums, so it's not just me. He said he would contact the engineering department and he also made an appointment for me (AGAIN) at the nearest service center 100 miles away.
If you have a problem with your brakes, just reply "YES" back to this post, then call the 800-FOR MERCEDES number with your VIN handy.
Again, please only those with a brake issue reply "YES" to this post so we can find out how many Sprinter owners on this relatively small forum have brake problems.
THANKS! And don't forget to call Mercedes hotline if you do have a problem! I believe I used "4" on the robo menu to get through to the person that helped me.

Looks like it maybe a design flaw. Read this from the Sprinter forum Report of mushy brakes on RV 3500's - Sprinter-Forum

[Nolefans]

Yes, I also have spongy bad brakes on my 2015 Solera 24R.

[Still Kickin]

Here is an informative reply from the sprinter forum, to the spongy braking issue raised here. Hope it describes what most are experiencing;

"Take a look at the Sprinters I have owned....2006 T1N 3500...2010 144" wb NCV3 3500....2011/2012 170" wb 3500's.....2014 170" wb 3500 4 cylinder 7 speed. The brakes in all of these Sprinters have lasted > 100k miles, never had to do any sort of brake job, I tow 5,200 lbs. of cargo trailer (with dual axles brakes) around 10% of the time putting the GCVW up into the 12,140 lb. range. And.....the brakes in all 5 of them have exhibited the same soft kinda squishy behavior on the first pump. I've made a bunch of serious panic stops (no double pump) with the trailer on the back (stand on the brakes and pray) and the brakes work just like they were designed to work. Last summer, just north of Chicago I came within a couple of feet of running over some idiot who pulled out in front of me (with the trailer) going about 25 mph and I'm going 50 mph in a narrow construction zone. The brakes all worked as advertised to turn an nasty rear end crash into nothing at all....of course I had quite a few choice words (not nice one's) to say as the idiot cruised off down the road. ABS works fine, even when all 4 wheels on the trailer lock up and smoke. And, I believe the design has remained virtually identical through all the model years. Vacuum reservoirs have changed in shape and location, but the function is still identical. Hope this helps"

[paul huyck]

Yes, I have always had spongy brakes. It seems that it is inherent to the vehicle. Probably caused by soft brake pad materiel. I have never had to make a panic stop, so I don't know how the brakes will react. I try not to stop too fast in fear of everything not nailed down to join me in the cockpit.

I had a problem on a recent trip that I wish to share and ask if anyone else has had the same thing. I have a 2014 Solera 24r with the v/6 diesel engine. I was travelling from Las Vegas to Valley of Fire SP in 100 to 110 degree heat, at 62 mph when the oil light started flashing on and off. I turned off the A/C and it stopped flashing. Five minutes later it started again, so I slowed to 55 mph, it then stopped and did not come on again. I had only 7,000 miles on the motor home. I called MBZ and was told by the service adviser that he had never heard of that problem and it was probably a defective sensor.. It seems to me that the oil pressure must have dropped to a level that would have turned on the light because of the heat making the oil too thin. I have not experienced the oil light problem again after driving about 1500 miles.

[Still Kickin]

The outside temperature should not have caused the oil light issue. Your MB uses mobil 1 synthetic, which does not thin during operational limits of the motor. Therefore, if it continues, I would take a short video as it occures, and have MB replace the sending unit under wattanty. Be sure to get your rpm's and speedo in the video. That way they will believe you. Just sayin'

Do check your oil level on flat ground, as sprinters tend to give different reading when out of level.

[JLeising]

Our 2012 Sprinter warns if the oil level is too high. I did have a oil light come on while driving in over 100 degree weather just after an oil service. I stopped and did the electronic oil level check on the side of the road - read "Hi". I drained about half a pint out and the issue went away.
Electronic oil level check - turn off engine. Turn key to position where all warning lights illuminate. Wait until the warning lights (except engine) go out. Press "M" button twice (first press shows miles to next service, second press starts oil level check). Display flashes dashes about seven times, then shows oil level ("OK", "Lo", or "Hi"). Easy to do at gas stops or morning startup without opening hood.
On mine, I believe they filled the oil to very close to the high level at the service and the oil expanded slightly with heat, triggering the warning.

[MiataHoarder]

Better yet, get an Ultra-Gauge discussed elsewhere. Around $70 and will display almost any parameter tracked by the Electronic Control Unit by plugging into USB port. The little credit card sized screen can continuosly display engine vitals that include coolant temps, oil pressure etc. while you drive.

Why? Eliminates uncertainty about driving or parking until help arrives. It will provide standard OBD (on board diagnostic) codes and allow you to clear them to see if they recur.

We encountered a very unhappy Solera owner who parked it because the check engine light came on. We stopped to help but couldn't because A) Weren't 100% sure if it was OK to keep driving - most folks believe its OK if no other trouble lights come on - it wasn't our Solera to risk; B) At that encounter, we did not have a code reader or an Ultra Gauge on board.

Had we had one, it would have told us it was a flaky sensor and which one it was - since that Solera drove OK, its likely had we reset the code, it might not have even recurred. After much angst, many phone calls and an unplanned overnight, the dealer changed out the bad sensor (had something do with turbo boost) and reassured the owner it would have been OK to drive on.

Sorry to get off topic - sounded important enough to comment.

[paul huyck]

Thanks Still Kickin, I will try that, but probably not until next summer when it is really hot again. Iv'e been on several trips since the problem oil light and it has not happened, but it has never been that hot either.

[MNtraveler]

Drawing on old mechanic days (we're talking high school here!) and ample experience since then (who's counting?) spongy brakes are almost always due to air in the brake lines that needs to be bled out. This is a simple fix and I would say it's not a warranty issue at all (although certainly a good "new delivery" issue for a new buyer). If you keep getting air in the line after bleeding, then that's another issue. But rather than writing NHTSA (which I otherwise surely support for any serious vehicle defect, which a brake defect would be), I would go get the air bled out of the lines.

PS: Brake pads are NOT soft and spongy.

[paul huyck]

I'm a retired mechanic after 45 years in the business. I would agree that the brakes need to be bled to correct the problem, but that is a simple fix and I'm sure that Mercedes would have done that long ago instead of having so many complaints about the spongy brakes. I have read all of the supposed fixes that didn't work and believe that is an inherent problem with the vehicle, such as soft brake pad materiel.

[MNtraveler]

Originally Posted by paul huyck

I'm a retired mechanic after 45 years in the business. I would agree that the brakes need to be bled to correct the problem, but that is a simple fix and I'm sure that Mercedes would have done that long ago instead of having so many complaints about the spongy brakes. I have read all of the supposed fixes that didn't work and believe that is an inherent problem with the vehicle, such as soft brake pad materiel.

I will certainly defer to your years of experience, however if one calls MB corporate about something that calls for bleeding air out of the brake lines, I wouldn't expect much help there. Help for that would be found at the MB dealer service department, a brake shop or a trusty service station.

I would love to see and touch a soft brake pad. Not sure how it wouldn't be ripped to shreds by truck wheels turning at 65 mph when the brakes are applied. All the ones I have ever handled were hard. But then hardness has its levels apparently.

If one steps on the brake pedal and it travels down 3" before engaging (which I believe some are complaining about), I would say that is compressing air in the line not brake fluid and the force hasn't even gotten to the brake pad yet. But I can't rule out some other issue like a master cylinder problem too. I'm just saying most commonly one would find air in the lines and it sounds like you agree on that point.

Air could be getting in the line due to a leak in the system letting air in or letting the fluid level get too low. A leak can be verified or ruled out by a mechanic when doubt the bleeding. Also pavement spotting or visually observed leaks could be a symptom.

Many thanks - appreciate hearing from someone with long experience in the field!

[MNtraveler]

Good article:

http://www.winbrake.com/training_spo...diagnosis.html

[paul huyck]

If someone came into my shop with the spongy brake complaint the first thing I would do is to bleed the brakes. My brakes were spongy compared to my previous 3 motor homes, all Fords, and they were spongy from the first day. With everyone experiencing the same problem why wouldn't Mercedes bleed the brakes, a very simple fix.

[cousin01]

AT the risk of touching off a model v model flame war, or violating some prohibition aganst posting from other forums....

this topic has also been discussed at length in the Navion discussion groups.

Here is one post that quotes a often cited Sprinter expert.

FWIW...


It is somewhat normal for the Sprinter chassis to have a soft brake pedal feel. It was a bit alarming for me too when we first were getting used to the chassis.

Dr. A, a foremost expert on the Sprinter, put the below test together a few years ago. Here's the test procedure that Byron shared out in a post:


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."
From Dr. A via Byron 07NH CA Thursday, March 29, 2012 8:41 AM

[MNtraveler]

Very helpful - thanks!

[MiataHoarder]

The air in brake line theory doesn't explain a firm pedal on the 2nd application of the brakes. If air remains in the brake line, how would one account for a the firmer pedal on the second push?

[Slow_movin]

Am now the owner of second Solera. First was a 2011 24s and it had long brake pedal travel. Had the brakes bled by a certified Sprinter tech. No help. He said the brakes were OK.
The present Solera 2015 24R has long brake pedal travel. My opinion is that the brakes are doing exactly what they are supposed to do. Have had panic stops and they worked just fine.
Just for the heck of it, will probably perform brake test as per cousin01.

[Jim D.]

Yes, I have the same problem. As an old time mechanic I thought I would have to bleed the brakes and have not yet got around to it. It seems however that bleeding the brakes would not solve the problem after reading some the efforts put forth on this forum. There has been no solution yet put forth by Mercedes???????????????