Maintenance items priority

[Lawrence Tarnoff]

Last fall, I took advantage of Cummins Coachcare program to evaluate our 2003 Monterey.  Here are the items they called out:
- belts beginning to wear, no cracks
- small leak in oil pan
- small leak surge tank
- differential noise
- muffler beginning to rust
- left front and rear shocks beginning to leak
- brake inspection: fronts, 60%; rears, 75%

In the aggregate, repairing all looks like big $$$ coupled with my annual oil change, generator service and hydrohot service.

Any thoughts about prioritizing the above list?

Thanks,

[Carl Boger]

For me the shocks and the differential noise would be the top two. 

I would probably replace all of the shocks, and then have the differential checked out.  Noise could be a bad bearing or worn out gears, or if your lucky just a low oil level.  It could leave you on the side of the foad if it goes out though.

Then I would move on to the 2 small leaks, hopefully they would be easy fixes.

Then the belts, followed by the Muffler which could be way down the road, and lastly the Brakes which look like they have a lot of life left in them.
Just my opinion,   Carl

[Lee Welbanks]

Last fall, I took advantage of Cummins Coachcare program to evaluate our 2003 Monterey.  Here are the items they called out:
- belts beginning to wear, no cracks
- small leak in oil pan
- small leak surge tank
- differential noise
- muffler beginning to rust
- left front and rear shocks beginning to leak
- brake inspection: fronts, 60%; rears, 75%

In the aggregate, repairing all looks like big $$$ coupled with my annual oil change, generator service and hydrohot service.

Any thoughts about prioritizing the above list?

Thanks,

First off, who was the shop that did this write up? All belts wear, no cracks and not slipping leave them carry a spare set. The oil pan leak and tank leak I would be more concerned with the surge tank leak as some are known to fail, just keep a eye on the oil pan leak.
Differential noise: what kind of noise, did they ck the gear oil level, how did they determine that the rear end was making noise. Almost all truck rear ends make some noise.
I would probably replace the shocks.
I think you need to get a second shop to look at your coach and see what they come up with.

[Gerald Farris]

Lawrence,
Most of the items on your list are normal conditions and look like a wish list for a shop that that is looking to boost sales. Virtually all 17 year old diesel engines have a small oil leak somewhere, so if it does not leave oil drops where you park and you never have to add oil between changes, its not an issue that needs to be repaired. All belts wear and all mufflers rust, so installing a new belt and muffler that show no signs of failure is a waste of money. All differentials make some noise, so what kind of noise and how loud? The brakes on your coach are probably original, and will probably out last you, so why replace them now?

Now we are down to the only things on your list that might be an issue, the shocks and surge tank. I would have both of them checked by a shop that you trust. The term "shocks beginning to leak" is questionable to me because shocks are the most oversold item in the service industry. Do you have any ride control issues? Last the sure tank, if it is leaking it will get worse, so where is the leak? If it is a loose clamp or fitting, tighten it, but if it is a crack in the tank, replace it soon.

Gerald   

[Dave Atherton]

Gentlemen, reading several maintenance tips, extra parts etc.  My suggestion that would be first on the list for health of your engine
let start at oil change periods. Taking of engine oil samples, this is the best way to understand what is going on inside your engine.
Yes belts, hoses , filters and carry extra all come into the picture but if major wear within engine itself the extra parts mean nothing
if the engine does not run. Looking back past 3 years and many complete engine failures that repair cost ran $ 35,000. To 65,000.
In follow up on these engine failures there never had oil samples taken and the lack of understanding what a oil sample means. Your
engine has a DNA like the human body, at doctor office a blood draw is taken same as your engine oil sample taken. The test results
will indicate problem and another blood draw will tell if problem is getting worse. The same for your engine particle count increase on
wear on component, check out and repair for minor cost instead of major failure In many thousands of dollars. I have posted Oil Sampling 
before on Ask Dave, technical information and cannot stress enough this is your first line of defense in health of your engine today.
Dave Atherton Retired Cat Mechanic

[Jason Worman]

Hello All,

This discussion has me concerned about an oil leak that has been happening. In the past year I have needed to add about 2 quarts of oil after putting on 2,000 miles. I have not been able to locate the source of the leak. I know that our engine is almost 30 years old so maybe this is to be expected. The oil pressure gauge always shows normal pressure. Very diligent to check oil levels and keep extras of belts, filters, and fluids on board. Thank you

Jason Worman

[Lee Welbanks]

Jason, As far as your oil consumption if it is not hitting the ground and under side of your coach it is going out of the exhaust. Check your oil level closer to find out how much your motor is using. Pull a oil sample to see if your motor is having a problem with wear.

[Jason Worman]

Lee,

It drips unto the ground so I get the famous oil spot. We are going to go to local Cat shop to get an oil change and filters, will get the oil sampled. I always check oil when engine is cold.

Jason

[Eric Maclean]

Jason
Checking for oil consumption one of the places people tend to ignore is the air compressor as they get old or worn they will move engine oil through them check you air drier for excess oil at the drain or air water dump.
Hope this helps
Eric

[Gerald Farris]

Jason,
If you are using (leaking) two quarts of oil a year, you do not have a problem that I would be concerned about. Your engine is not even down to the add mark on the dip stick until it is a gallon low. In my other life working on cars, General Motors would not pay for warranty repairs on a car unless it was using more that a quart every 1000 miles, but they paid for any leak repair. However, If you want to stop the oil spots, it is up to you about how much that is worth to you. A leaking oil pressure switch or filter base gasket is probably worth fixing, but something like a rear main seal is a totally different story.

Gerald

[Jason Worman]

Gerald,

Thank you for the input. Prior to our purchase the engine and transmission were pulled to replace a broken flywheel as the coach was inoperable. You would have thought with those removed the past owners would have replaced the seals. I called the shop to ask if the seals were replaced and they were not. At this point will have the engine inspected for the leak, if something simple like you mentioned will have the work done. Will the seals get worse over time? We have already spent so much on this coach already, probably at least double for what we paid for it, will just keep monitoring the oil levels.

Jason Worman

[Gerald Farris]

Jason,
If you have a rear main seal leaking, they tend to get worse over time. But, at your usage level, the odds are very high that the odd seal will out last you.

Gerald

[Steve Huber Co-Admin]

Hi Jason,
If you are going to have a shop advise you on this, suggest you have them steam clean the area before inspecting for leak location. It can be very difficult to ID a leak source on an engine that has years of grime, etc it.
Steve

[Eric Maclean]

Jason
As Steve said a clean engine is easier to locate a leak on .
There are also florecing dyes that can be add to the oil when used with a black light they florece and show the leaks local.
Eric

[Dave Atherton]

Jason, the oil leakage you indicate there are two sensors on rear of front gear timing housing
location behind the Heui pump that weep engine oil. There is a caterpillar service bulletin out
for these sensors weeping engine oil because of design that uses one o-ring and there is not
a repair or upgrade for them. Look at your engine from underneath and you can see oil tracking
present. Buying new sensors along with new o-ring will not fix oil weeping. This is a good location
for location on oil leakage to look at. Dave Atherton Retired Cat Mechanic