In our quest for a Class A our options are a used DP that is about 6 years old or older or a newer gasser. What I would like to know if how the used DP reliability would be. I know it would depend on how maintenance was performed and how often, but even with that systems can and will fail. These items I am most concerned about since I don't have experience with them:1. How long will the air suspension last before it starts to have problems and what maintenance is necessary?2. Air brake system. How long do the shoes typically last and are they like the old days when cars had drum brakes and they have to be adjusted periodically, unlike disc brakes? 3. Does the air suspension and brakes use the same compressor system?4. I am familiar with Cummins since we have one in our Dodge pickup, but what things are there to look for with a Cat engine?5. Does anyone know if the Cummins in a Class A has the same or similar maintenance requirements as the pickup version?6. What required maintenance is necessary for the transmission and is there anything to look out for?7. I usually do most of my maintenance work, is the engine area easily accessible within reason?8. Is there a chassis/owners manual that has recommended maintenance schedule?9. Are parts readily available if something needs to be repaired?10. Anything else I should be concerned with or need to watch for?I know this is a quite lengthy list, but just want to be prepared.Thanks everyone. You have been very helpful so far.John

John,Answers in SOLID LETTER CAPS.JCGibson wrote:In our quest for a Class A our options are a used DP that is about 6 years old or older or a newer gasser. What I would like to know if how the used DP reliability would be. I know it would depend on how maintenance was performed and how often, but even with that systems can and will fail. These items I am most concerned about since I don't have experience with them:1. How long will the air suspension last before it starts to have problems and what maintenance is necessary? AIR DRYER SERVICE/REPLACEMENT IS ABOUT THE ONLY MAINTENANCE ON AN AIR SYSTEM. MOST USE THE ENGINE MAIN AIR FILTER RATHER THAN A SEPARATE FILTER. 2. Air brake system. How long do the shoes typically last and are they like the old days when cars had drum brakes and they have to be adjusted periodically, unlike disc brakes? SOLD OUR FORETRAVEL WITH 170,000 MILES AND STILL 50% OF SHOES LEFT. SURE, IF ONE DOESN'T KNOW HOW TO DRIVE A DIESEL AND DOES NOT USE THE EXHAUST/ENGINE BRAKE, YOU COULD WEAR OUT BRAKES. 3. Does the air suspension and brakes use the same compressor system? YES.4. I am familiar with Cummins since we have one in our Dodge pickup, but what things are there to look for with a Cat engine? NO SIGNIFICANT DIFFERENCE. BOTH CATERPILLAR AND CUMMINS MAKE EXCELLENT ENGINES.5. Does anyone know if the Cummins in a Class A has the same or similar maintenance requirements as the pickup version? I DON'T KNOW PU MAINTENANCE, BUT CUMMINS HAS RECOMMENDED MAINTENANCE SCHEDULES IN THEIR OWNERS MANUALS AND PROBABLY ON-LINE.6. What required maintenance is necessary for the transmission and is there anything to look out for? ALLISON HAS RECOMMENDED FLUID/FILTER CHANGE RECOMMENDATIONS ON THEIR WEBSITE. BIGGEST VARIABLE IS SYNTHETIC FLUID VS DEXRON.7. I usually do most of my maintenance work, is the engine area easily accessible within reason? MORE SO ON SIDE RADIATORS, BUT EVEN REAR RADIATORS PROBABLY NO WORSE THAN MOST GASOLINE C'S AND A'S.8. Is there a chassis/owners manual that has recommended maintenance schedule? YES, GENERALLY EACH MAJOR COMPONENT COMES WITH A MANUAL AS WELL AS A GENERAL ONE FOR THE COACH.9. Are parts readily available if something needs to be repaired? YES, MOST COMPONENTS ARE COMMON TO TRUCKS AS WELL AS DP'S. SURE, IF OVER 20 YEARS OLD, MAY FIND PARTS SOURCE ISSUES.10. Anything else I should be concerned with or need to watch for?I know this is a quite lengthy list, but just want to be prepared.Thanks everyone. You have been very helpful so far.John

Do you MIND doing maintenance? Our DP has a two AC filters, an air intake filter, an oil filter, two fuel filters, a coolant filter and three hydraulic filters. There is a lot to keep up with. I rather like the discipline of it.We had to order a hydraulic pump from out-of-state. Second day delivery was reasonable.Engine access is surprisingly difficult. There is a lot of stuff jammed in there. I recently removed a hydraulic thermostat for inspection. I could see it and touch it. The back bolt required clearancing the part with a hacksaw and grinding a socket paper-thin on one side to get the bolt removed. Probably more a symptom of modern design than DP problem.Our air bags are in decent shape after 16 years of use. I plan to replace them this summer as a preventative. Shocks are on the list too - 50K miles according to records, though some look original. Brakes are original and are fine. Previous owner taught me to use the exhaust brake!Most DPs will likely come with a maintenance schedule, or one will be readily available. You will always be doing a bit of web search for quantities, methods, etc.Matt B

Brett's advice was what inspired me to do my own maintenance, aside from my just being a cheap-ass. His opinion counts.Matt B

oldmattb wrote:Brett's advice was what inspired me to do my own maintenance, aside from my just being a cheap-ass. His opinion counts.Matt BDoing it cheaper and not paying someone else for what I know I can do is my goal. I work on everything else I have; Corvette, Cobra replica, my wife's car and the Dodge pickup.One other thing. What is the slobber tube? I have read some comments about that, but have no idea what it is.Thank you both for the quick responses.John

Slobber tube is the open crankcase breather on all diesels before the EPA tightened up specs, after which they all had to go to closed crankcase ventilation.

Used DP Reliability | Good Sam Community

16 Replies

Snomas
Explorer
Jan 07, 2015
I thought our Cummins would last to 250-350K w/out major repairs. I have done all regular required maintenance over the years. Last 18 months have replaced the following: exhaust manifold, new head, high pressure fuel pump. lift pump, fuel lines, turbo charger, hydraulic pump, shocks, muffler, fuel pump sensor @ $$$$$$ cost!!! That doesn't include being hit w/ Hail storm last July and had to replace the entire roof, ac units, etc, and repaint 2 sides of the MH. Just took it in for a diesel inspection and a driver hit the front and now have a new paint job on the front. Murphy's law? We still love RVing and would not quit for anything!!!
Dachristianman
Explorer
Jan 06, 2015
Speaking of tough, I went to replace a headlight bulb on a car, and the first step said to remove the front bumper fascia. These new vehicles are crammed, but the dependability is better than it has ever been.
DSDP_Don
Explorer
Jan 06, 2015
I think "bluwtr49" brings up a good point. If you can find a reasonably priced shop, it's not so bad to have it done. I do all of my own work and still enjoy it. It also gives me an opportunity to look for things that are broken or breaking.

BUT.....as I get older it gets tougher. I'm guessing by the time MOST get to the age of owning a DP, they either have the funds to just pay and have it done, or are physically getting to the point where it's tough to crawl around and under a DP.
bluwtr49
Explorer II
Jan 06, 2015
I do none of my own work on the drivetrain but if I did it wouldn't be tough. Interestingly, I not certain that routine maintenance it that much cheaper DYI than having a truck service center do the whole job.

I feel that since most of the cost of an oil change is in the cost of the fluids anyway an hour of labor is way cheaper than me trying to deal with 36 qts of hot oil. Beside the truck centers do a full on inspection of all the other chassis components.

So far repairs on anything drivetrain and chassis related on my two Beavers have been zero.
JimM68
Explorer
Jan 06, 2015
Agree with all above, particularly listening to Brett.

If you always do your own anyway, a DP won't be anything earthshaking, just more of the same, a little bigger.

As for the DP, don't let the maintenance scare you away. There is no substitute for the power, ride, handling, and pure size of a modern diesel pusher motorhome.
BurbMan
Explorer III
Jan 06, 2015
oldmattb wrote:
It was installed before the fan shroud and fan were assembled. Seriously, it took two hours to get that bolt out.

Man, I hate stuff like that. I had a similar issue with one bolt on the motor mount bracket trying to change the oil pan on a 3.8 V6 in DD's Grand Prix.

Hope you replaced it with an internal hex or torx or something else so it didn't take 2 hours to get it back together!
tinkerer
Explorer
Jan 05, 2015
If you are mechanical and want to do your own service work you will be comforted in the fact that things will be done right. Most shops work on flat rate and commission and it seems everybody tries to cheat the system to make an extra buck. More than once I had to fix a problem right after it was supposed to be fixed by an expert.;)
Bikeboy57
Explorer
Jan 05, 2015
JC,

With those cars and you doing the wrenching, you will take to the work on a DP like a duck to water. The mechanical stuff will come like second nature. Hopefully you already are familar with a Voltmeter. You will also need basic electrical skills to diagnose and repair.

With your background, I predict you will be a lot happier than those who have to pay for sometimes competent and sometimes incompetent work.

You probably already have most of the tools you need if you work on those cars.

One thing to add, always, always, always crib or block the coach before getting underneath. Air suspensions can suddenly fail, and that will ruin your day if you are under it.

And as others have said, when Brett speaks, it's a good idea to listen.
oldmattb
Explorer
Jan 05, 2015
I wish. There was no room for the crow's foot to move, even if I had gotten it on. The bolt was less than the thickness of the saw blade away from the thermostat before I started, and probably an inch from the fan shroud.

It was installed before the fan shroud and fan were assembled. Seriously, it took two hours to get that bolt out.

Matt B

BurbMan wrote:
oldmattb wrote:
The back bolt required clearancing the part with a hacksaw and grinding a socket paper-thin on one side to get the bolt removed.

Sounds like a crow's foot would have been a better tool than a socket.
BurbMan
Explorer III
Jan 05, 2015
oldmattb wrote:
The back bolt required clearancing the part with a hacksaw and grinding a socket paper-thin on one side to get the bolt removed.

Sounds like a crow's foot would have been a better tool than a socket.