Rotors and Brake Pads

Symptoms: Grinding noise while braking, brake pedal feeling like one was stepping on a wheel of baked brie.

One of Abby's rear rotors. That crack is a good sign the brakes needed replacing.
One of Abby’s rear rotors. That crack is a good sign the brakes needed replacing.

Problem: Abby still had her original brakes and rotors. These poor pads and rotors had 86,000 or so miles on them. Several thousand of those miles had some extra abuse because we were hauling our cargo trailer. Which didn’t have brakes so Abby was responsible for stopping not only her weight, but the weight of the cargo trailer.

Solution: Have Dave replace the brakes! We were fully expecting this replacement, so we are considering this to be a maintenance activity.

When Dave got one of the rear rotors off (pictured) there was a significant crack formed and others starting to develop. All the brake pads were worn, not far from the point of the wear sensor.

Dave purchased the rotors and brake pads from Advance Auto Parts.

Degree of Difficulty:

Moderate. Front and rear brake replacement should each take approximately 3 hours. Bravery and a good jack is required because it is such a large vehicle. Caveats to the degree of difficulty are

  1. Dave has replaced the brakes and rotors on smaller vehicles.
  2. No unexpected challenges arise during the replacement.

Parts/Tools Required:

  • Rotors
  • Brake pads
  • Breaker bar
  • Wrenches
  • Jack
  • Flattened cardboard box (cushions the gravel of the storage lot)
  • Knee pads (like floor tilers wear)
  • An extensive repertoire of curse words (Sailors should be jealous)

Repair Tips/Comments:

  • Unlike a typical Mercedes sprinter chassis, the rear brake pads and calipers are the same as the front brake pads. Winnebago wanted to make sure there was stopping power, because there is a large amount of momentum in a RV lumbering down the road.  One only discovers the ‘oh, haha, you thought you had regular rear brakes’ switcheroo after the RV is up on a jack, completely apart, and nothing fits.
  • The rear (front!) brake rotors are a snug fit and require some persuasion when being put back on (tapping with a hammer). The hub assembly is hollow and releases a very fine rust dust that can settle into the threads of the rotor bolt holes. Blow out the bolt holes with compressed air BEFORE putting the bolts in.
  • If you didn’t blow out the bolt holes with compressed air and the bolt threads freeze up, brute force is required to remove the bolts. The bolt holes will need to be re-tapped, and you’ll need to stop at 4 different hardware stores to see if anyone carries a Grade 8 14mm bolt with a 1.5 thread pitch (start at Ace, and you might have to stop at only one hardware store).  Mind you, it’s 3:30pm and snow is forecast for the next day.
  • Stop at one Advanced Auto Parts store only to be told the part is in stock at another location? Purchase said part at first location and drive to the second to pick it up, only to be told they are out of stock? They have a special area where they set aside parts to picked up. “Oh, sorry man.  We found your brakes.”

Routine Maintenance: Oil Change, Fuel Filter

Symptoms: None

  • Manufacturer recommends to change the oil every 10,000 miles, but Dave changes it on an as needed basis. Need is determined by how much we have traveled, the wear on Abby, and if we are towing. We put approximately ~7500 miles on Abby since her last oil change (move to California, northern California vacation, move to Colorado). The majority of these miles were done while towing our small cargo trailer; it is best to increase the frequency of all maintenance when additional stress is present.
  • The fuel filter should be changed every 20,000 miles (manufacturer) but there is not consensus on the Winnebago View forums. Some people change it every 10,000 miles, others 40,000 miles. We (Dave) changes it more frequently. Why? If the fuel filter fails, the injectors could get clogged and the injection system would need replacing. Might as well spend the few extra dollars to save thousands.


  • Follow the manufacturer’s specifications for the oil, and all other fluids with the exception of the windshield washer fluid. Don’t cheap out.
  • The fuel system needs to be bled of air when the filter is replaced.   The filter replacement is easier done with two people. One person turns the ignition to the point where the glow plugs are turned on and the fuel system is pressurized (do not turn over the engine). The other person watches for the air to bleed out and for fuel to flow.  They then holler at person one to turn the key to the ‘off’ position.
  • The fuel pump runs for a few seconds even after the key is off. Consider getting a fuel overflow container larger than a beer bottle.  There may have been some swearing.  Eau de Diesel is not sexy.
  • Experience level: If you can change your car’s oil, you can change the oil in the RV. The fuel filter is more difficult to do and requires bleeding the system. Increases the routine maintenance skill level to intermediate.

Disappearing Window

Symptoms: Partially down passenger side window dropped completely down when Jess’ arm was rested on the window.

An open window in June may not be a problem, but we were camping in the Sierras and had witnessed snow flurries the night before. Having an open window would result in a rather chilly night.  We were also in bear country. Top Gear may not be the most educational show, but the one thing we did learn from watching the Botswana special (go to minute 34), is when you are in an area with predators, you best animal proof your car. An open window is not animal proof. Thus it was decided we (Dave) would fix the window.

Plastic panel removed from the door.
Plastic panel removed from the door.

Problem: The window likely came off the track within the door.

Solution: The door paneling had to be removed to access the window. Close investigation showed that the arm of the the opening mechanism was bowed. This allowed the glass to slip off the track during a certain point of window travel and fall into the door cavity.

To straighten the arm, Dave employed a lever in order to apply sufficient force. Jess was concerned with the lever slipping and breaking the glass, so the glass was removed while Dave worked on the arm. With the arm straightened, the glass was returned to the track and the window was tested to ensure smooth motion.

The window back on track and the arm straightened.

The final step was putting the door back together; make sure all the tabs are lined up correctly.

Repair Tips/Comments:

  • The hardest parts of removing the plastic door paneling was figuring out where the two screws were hidden and which way to lift the panel to remove it without breaking the plastic tabs. This also required unplugging the electric window control so the wires could be threaded through a hole for easier removal of the panel.
  • The glass was not broken and the window motor was still functional. If the motor had been broken, we would have likely had to figure out a way to block the window in the up position.
  • Dave has restored cars before, so he was familiar with this repair. Otherwise, it may be higher on the challenge scale. Go slow and take the time to thoroughly look over the problem.
  • Dave at the end of a successful repair. Wouldn't have happened without Chewie's supervising.
    Dave at the end of a successful repair.

    You need a helper dog to supervise your work.

2016 Colorado Move: Mechanical Mishaps

No trip would be complete with out some mechanical issues. Especially on a holiday weekend traveling the loneliest road. Fortunately, the check engine light and the flat tire were not as serious as the failed turbo resonator or transmission breaking.

Check engine light: 

The check engine light came on coming into Carson City, Nevada after dropping down the Sierras. Dave used an OBDII reader to obtain the error codes associated with the check engine light.

Error codes: Cam position sensor, O2 sensor error

Fortunately, where we pulled over in Carson City was not far from the Dodge dealer. The shop manager reviewed the codes and said that the cam position sensor can ‘hiccup’ especially when traveling from high to low altitudes. This results in a cascade effect that causes the O2 sensor to error as well. He was happy to report that as long as the check engine light wasn’t flashing, we could continue to drive Abby. If we wanted peace of mind, we could have it checked out, but the soonest he could get to it would be Tuesday. As much fun as a two night minimum in Carson City sounded, we decided to push onward. We bought a Good Sam towing membership.

Total time lost: 1 hour

Repair difficulty: Easy, it was simply getting advice from a shop guy. Google indicated that replacing the sensors was not difficult and could be done in a parking lot or campsite. No auto part stores had the parts in stock. Abby is due for a thorough tune-up, including a transmission flush, at the end of this trip. We are going to pay the money and let a Dodge dealer give Abby some TLC.

Flat tire:

Flat_01Our flat tire occurred approximately 40 miles west of Austin, NV. We were losing approximately 2 lbs of pressure every mile. How did we know? Dave purchased and installed EEZTire Monitoring system that reports the pressure in each tire via RFID. Fortunately, the Edwards Creek historic marker was close by and we were able to pull over in a safe place to change the tire. As Dave changed the tire, Jess wrangled the dogs and Alex, with marginal success. The dogs had to be returned to Abby. Alex ran around with tools key for changing the tire and found every bit of dirt on the Abby and transferred it to himself. Inspection showed that the valve stem had failed. To add to the fun, the spare tire and the other dualie tire needed to have their pressures increased. Our 12V electric pump burned out; fortunately, we had a bike pump with the appropriate fitting in the trailer.

Flat_02After completing the tire change, we stopped in Austin, NV to fill Abby up. Dave inquired about tire repair and was directed to Wayne, the tire guy. He provides 24/7 service for this isolated area and was able to fix the tire.

Total time lost: 2 hours

Repair difficulty: Easy. If you know how to change a tire on a car, you can change a tire on an RV. Parts are just bigger and heavier, technology and theory are the same. This is a key skill otherwise you will be waiting for several hours in the sun for assistance. And there may be no cell service.

Transmission Failure: October 2015

Abby being towed from the EZ-Pass administration building parking lot.
Abby being towed from the EZ-Pass administration building parking lot 15 miles from home after a trip to Acadia National Park.


  • Pressure applied to gas pedal, engine revved, speed did not increase.
  • Shifting into various gears and stepping on the gas resulted in more engine revving, and at best, a few feet of movement.
  • During a test drive at the dealership, Abby threw a fault code that the technicians had never seen before and required a call to Mercedes headquarters (yup, Germany) for correct diagnosis.

Fault Codes:

  • There were fault codes, we just don’t remember them. We might have written them down somewhere. Time will only tell if we find them.

Problem: We initially hoped that a failed seal leading from the transmission case to the control board had caused a temporary short. Dave did some parking lot diagnosis, and thought that a failed seal might be causing the electrical connection to the computer to short out.  The connection was cleaned, Abby drove for about 30 feet and then died again.

We now know what an emergency, after-hours tow of an RV costs.

We also now know what a scheduled, normal business hours tow of an RV costs.

Solution 1: We had Abby towed to a friend’s nearby shop, where Dave hoped to work on it some more the next day.  The next thing to check was the transmission computer.  Dave followed the wiring back inside the cab and pulled the transmission computer.  As suspected, transmission fluid had wicked up the wires about 3 feet, and into the transmission computer. Dave carefully opened the computer case, cleaned and dried everything off, reassembled it, and reinstalled the computer.  Abby was placed in ‘Drive’ rolled about 30 feet, and quit again.  So much for that solution.

Solution 2: Abby was towed to Carman Dodge for professional diagnosis and repair. What was projected to take a week took a month. Initially, the error code that was being thrown was easy to diagnose.  The technician thought it was a bad shift solenoid on the valve body.  This was going to cost a fair chunk of change, but not the end of the world.  A new valve body was ordered and installed.  Abby started up and ran fine.  She made it about 3 miles into the mechanic’s test drive, and that’s when something gave up deep inside the transmission.

The error code Abby threw was something the dealership had never seen before and they had to call the mother-ship in Germany.  The new code meant ‘install a new transmission’.  Sigh.  The dealership called with the bad news.  After some pointed questions about having to pay for diagnosis time, a new valve body, AND now a new transmission, things were getting a bit testy. (It should be noted that it was not Jess conducting this interrogation, but Dave. The good cop was having a bad day.)  The service manager at Carman admitted that they misdiagnosed it, and they would eat the cost of the diagnosis and the valve body.  We have to give them a lot of credit.  In a day and age where dealerships are known for ripping people off, they did a stand up thing, and made it right.  We still weren’t happy about having to buy a new transmission at 65,000 miles, but Abby got one.

We purchased a Good Sam membership and towing coverage.

Repair Tips/Comments

  • Mercedes recommends servicing the transmission every 90,000 miles. Abby had 65,000 miles on her. Reports from the owner’s group is that more transmissions have failed in Sprinter based RVs than probably should.  RVs are often loaded to their maximum limits, and may also be tasked with towing, too. The recommendation is to service the transmission every 30,000 miles or so. Especially if the vehicle has been used to tow.
  • The repairs Dave attempted are not for the weekend mechanic who is used to changing a vehicle’s oil and maybe air filter. Only recommended for a seasoned mechanic. The transmission fix – just send to a professional.
  • Abby’s stay at the mechanic was not completely unfortunate. We were trying to sell the house at that time, so it was good she was parked somewhere safe during showings. Apparently a RV parked in your driveway is not a selling feature. The month long absence completely threw off our packing schedule and contributed to move out chaos.

Turbo Resonator Failure: June 2015

Dave working on the turbo resonator.
Dave working on the turbo resonator.


  • Acceleration was not smooth, check engine light came on. Symptoms disappeared on restart of engine.
  • During hill climbs, acceleration decreased dramatically, symptoms disappeared for time after engine restart. Each successive restart resulted in a shorter and shorter time before symptoms represented. Check engine light came on after multiple restarts.

Fault Codes:

  • OBD II P0121: Throttle/Pedal Position Sensor/Switch ‘A’ Circuit Range/Performance Problem
  • OBDII P0299: Engine Turbo-Supercharger Boost
The split turbo resonator. That seam should not have that gap.
The split turbo resonator. That seam should not have that gap.

Problem: The turbo resonator is made of plastic and the seam failed. This is a known failure point according to multiple forums. Mercedes has been through three revisions of this part in plastic and it keeps failing.

Solution: Previous owner had the turbo resonator replaced once by Mercedes dealer and they put in another plastic version. Previous owner decided to purchase an all aluminium replacement part and it transferred to us when we purchased Abby. Repair was simple enough, complicated by rain and being parked in an emergency pull-off area along I-76W. Requires low clearance 1/4″ socket (which we did not have). We limped into Somerset, PA with an escort by a Herring Motor Company tow truck (fortuitously helping an automobile with issues in our emergency pull off), to purchase a $9 socket wrench to properly execute the repair. Dave performed all mechanical repairs. Jess served as chief child and dog wrangler and did not bake cookies while waiting for the repairs to be completed.

Repair Tips/Comments:

  • Still have the plastic turbo resonator in? Just order the all metal version and replace it before it fails on the road. Repairs are always easier on a nice day, parked in your driveway/workshop, without traffic flying by at 70+ mph. An inexpensive repair (if you do it yourself, several hundred at a dealership) that will save you time and headache on the road.
  • This is a repair you can do yourself if you are comfortable doing basic maintenance work on your vehicle. It is two hose clamps. That is it. The working space is tight, which adds to the challenge.
  • Have your outdoor rug easily accessible. It doubles well as a work pad
  • The metal part does whistle. So don’t panic. It may be noisier, but it won’t leave you stranded on the side of the road.