Coach Care: Care and Feeding of Motorhomes

By Brett Wolfe 5/10/01

1993 Foretravel U240. (Most items apply to other coaches as wll)

1. FMCA publishes a good basic “Motorhome Checklist” in almost every issue. (October 2000 page 165)

2. Useful web site: www.rv.net

3. See also the Suspension document covering the torsilastic suspension.

4. Grease the Cat 3116 engine upper idler pulley (grease zirk) with a small amount of grease during chassis lube jobs.

5. On the front axle, check draw key torque every other lube interval. They (2) hold the kingpin in place! Torque spec is 30-45 ft lbs with front wheels off the ground. Rockwell (now Meritor) shop manuals are available on line at: www.meritorauto.com. Go to technical library.

6. If the serpentine belt tensioner bearing goes bad, replacement bearings are available at most auto parts houses–no need to pay $100+ for tensioner assembly. Use a small vice to press in the new bearing.

7. There is a Cat service bulletin (handed out at the 7/99 FMCA seminar) calling for a 2 micron final fuel filter. Use a Cat filter or insure that others meet that spec (the Fleetguard fuel filter used at Foretravel is rated at 15 micron per Fleetguard).

8. Monitor air filter minder weekly. Check it at each oil change by pulling the vacuum line from the filter end and sucking on it. The minder should turn yellow then red. Push the reset button and reconnect the line. Like a fuel filter, there is no air filter “average” life. They could go 50,000 miles in low dust conditions or clog up in 100 miles on a dusty road.

9. Check the engine coolant nitrates/coolant additives at each oil change (either with the inexpensive litmus paper type testers available at Foretravel or with a more expensive kit. The coolant ”filter” replenishes the nitrates. Per Fleetguard, the nitrates from a new canister dissolve within a few hours, so if nitrates were very low, retest and install another ”filter” if needed. “Filters” come with different charges of nitrates. Too much is a bad as too little.

10. When changing engine coolant every two years, replace hoses (if they are over 3 years old) and the thermostat. Use a low silicate (not automotive) antifreeze and distilled water (50/50). The 2000 Cat parts book incorrectly shows a rectangular thermostat gasket-the correct one has a round center & two bolt holes. Use coolant “filter” with a high dose of nitrates sold specifically for this initial charge.

11. Most Cat 3116 engine oil dipsticks are miss marked. Per Cat, the correct procedure to insure the correct oil level (do this at the next scheduled oil and filter change) is to drain the oil and replace the filter. Add exactly 2 quarts less than the engine requires (for the 3116: 21 qts minus 2qts equals 19 quarts), run the engine until oil circulates. Stop the engine, and after waiting for the oil to drain down to the pan, mark this dip stick level your “add” mark. Add the last two quarts. Mark this level the “full” mark. Most 240’s full mark on the dipstick is actually 2-3 quarts overfull. My full mark is halfway between the original full and add marks.

12. Replace drive belts every 2-3 years. Save the old belts for spares. Check the serpentine belts carefully for cracks at every oil change.

13. Visually check the Racor fuel filter for’ dirt or water daily. With the high amount of fuel that goes through the filter/engine (most of which returns to the tank) it is a good idea to check it 50 to 100 miles after a fill up.

14. If you drive in mountains some form of auxiliary brake is necessary. If not a late model with transmission retarder, an exhaust brake (Le. Pac Brake that we have) can be added after verifying with engine and transmission manufacturers that your model is exhaust brake ready.

15. Drive with the transmission “mode” button engaged for better economy and less shifting, particularly while on cruise control. Mode lowers the RPM at which the engine up shifts at higher throttle positions only. and holds the transmission in a gear longer before downshifting. At lighter throttle settings, mode makes no difference.

16. Change transmission fluid and filters every 25,000 miles years miles per Allison. More often if you have a late model with a transmission retarder. Change rear axle fluid and front wheel bearing fluid (both axles use the same oil) on the same schedule. We use synthetic gear lube in the axles.

17. If you have to replace the transmission ECD, consider a CAL of 2500 instead of 2600. It shifts the transmission at lower RPM for better economy, less noise and more closely follows the peak torque curve of the engine. I also had the exhaust brake preselect set to 5th gear so the brake can be used at freeway speeds without high-reving in 4th. I have all the before and after shift RPM’s and speeds if you are interested.

18. Occasionally check the transmission for fault codes. With the ignition on/engine off, simultaneously press the up and down arrows on the transmission selector. The codes will be displayed as a two-digit number followed by another two-digit number. Scroll though fault codes by pressing the mode button. To exit the test and clear stored fault codes, hold down the mode button until it beeps TWICE and the windows return to N. A free list of fault codes is available from Allison. Late model Allisons with fluid level check from the transmission selector, have a somewhat different procedure.

19. Check battery water every two months–add distilled water. If unable to check often enough to keep batteries happy, replace them with batteries requiring no service (gel, AGM, Optima). For house battery, be sure to get deep cycle batteries-they are physically different from starting batteries.

20. If the converter (11Ov to 12v) needs replacement and your plans don’t include an inverter, consider a “smart charger” such as the Statpower True-Charge 40+. It is quieter, more efficient, much better at charging the batteries and has a “storage mode”.

21. Store windshield wipers off the windshield. Either leave them tipped out or place a tennis balls under the arms. Because the arms are under much more tension than on a car, the blades take a set if left on the windshield.

22. While storing the coach, if possible, drive it 20-30 miles every 10-14 days. Operate everything including running the gen set under at least 50% load for 30 minutes.

23. While storing your coach, drain the water from the ice-maker mold and leave the refrigerator and freezer doors open. A 3′ small diameter plastic hose works well to suck out the water.

24. If storing in a humid climate, place a small house type dehumidifier (about $150) on the galley counter, draining into the sink and set at 50% humidity. It will keep the coach dry and prevent that musty smell.

25. If diesel fuel will not be used within one month, add a biocide to prevent algae growth.

26. If your fuel gauge (Centroid fuel sender unit) reads “overfull” for hundreds of miles then drops suddenly, the sender unit needs adjustment. Fill tank. With someone looking at the gauge, use a small phillips head screwdriver to adjust the tiny screw on the sender unit of the fuel tank Gust forward of where you put in fuel). Very small changes in the screw move the fuel gauge indicator quite a lot. Set the indicator so it reads full BUT NOT OVERFULL with the tank full.

27. Bleed air tank drains weekly. If water is present, replace the air dryer desiccant canister.

28. If the air dryer is continually purging (sneezing), install an external check valve (available from Foretravel) rather than rebuilding the whole dryer.

29. On interior wood: use Orange glo (available at grocery stores).

30. Remove scratches from Corian by sanding with 320 then 400-grit wet-dry sandpaper. Using it wet keeps the dust down. Then finish with a white extremely fine Scotch-Brite pad. For a shiner finish, use 600 then 1000-sandpaper then polishing compound. Note: the shinier the surface the easier it shows scratches. For a quick touchup to the factory semi-gloss finish, use the Scotch-brite pad.

31. When the fresh water tank level is less than 1/4, do not leave the pressure water on while you are driving or not in the coach. The pump could run out of water and burn up. Just turn the pump on and off as you need water.

32. If the fresh water pump cycles with no demand, there is a leak!

33. If the fresh water pump cycles rapidly on-off-on-off… when a faucet is open just a little, the accumulator is bad or out of air (there is an air bladder in the tank). Check the pressure. with a tire gauge. Inflate to the “cut-in” pressure of the pump-approximately 25-30 PSI. If water comes out the valve, the bladder is broken and the accumulator must be replaced.

34. Replace propane regulator (on propane tank) every 4 years. Like all rubber parts, time destroys it. They are around $20.

35. Check the burner area of propane furnaces at the beginning of each season to make sure there is no leak of combustion gasses to the interior. Hold a lit cigarette next to the combustion air intake on the outside of the furnace. Have someone smell inside the coach near the heater outlets for cigarette smoke.

36. If there is an “old rubber/tar” smell from the rear furnace on a Foretravel, it is likely to be the original sound deadening material over the right rear wheel well and immediately below the heater. The original rubber insulation smells, even though it is not getting hot. Remove the air return duct and smell to confirm this. I lined this area in 15 minutes with 2 sheets fiberglass (filon) scraps and some metal duct tape and solved the problem.

37. Service the refrigerator burner annually, more often if used in humid and/or on rough roads. Rust clogs the burner and needs to be cleaned out. There are simple step by step directions in the refrigerator owners manual. It takes 15 minutes and no special tools are required.

38. Black flecks in the ice from the in-refrigerator ice-maker usually means that the ice tray Teflon lining is flaking off. The ice-maker is fairly easy to replace complete. Cost of parts $150-180.

39. With compressed air, blowout the burner area of the hot water heater. This will minimize the discoloration of the side of the coach above the heater. Burning a wasp’s nest or 6 months accumulated dust will cause smoke! After cleaning, turn on the heater and look for a blue not yellow flame. If it is not blue, the air regulator needs adjustment, an easy job.

40. For safer drinking water and fewer problems with the fresh water system, fill the coach through a 5­micron filter (available at Home Depot for canister style filters including RV filters). Well water at many campgrounds has sand and sediment that can harm your water system. DO NOT USE A FILTER WITH CHARCOAL AS YOU PUT WATER INTO THE T ANK, you will remove the chlorine and make storing the water very dangerous. The standard ADC filter under the sink removes chlorine just before you use the water. Change the ADC filter element every year or 750 gallons of water filtered.

41. If you travel off the beaten path, carry a spare fresh water pump, they can be hard to find. If you might need to fill your fresh water where city water pressure is minimal or water is not available from a hose, the spare pump can be assembled (for under $10) to pump water into the coach. Let me know if you want details.

42. Do not leave shore water on while you are not in the coach. A broken pipe could send thousands of gallons of water into your coach. Also, use a pressure reducer for water entering the coach.

43. When connecting or disconnecting the shore power cord, be sure that the shore side breaker is OFF. It is also a good idea to turn off all 110-volt circuits on the coach-until polarity and ground have been confirmed when plugging in. If the breaker is on, the tips of the shore power cord will be burned a little each time they “make or break” the circuit.

44. Replace tires every 4-5 years regardless of tread. Sidewalls crack, causing blowouts. If your fingernail will go into a sidewall crack, it is time for new tires. The last three digits of the DOT number on the tire indicate the week and year of production (ie. 416 was built the 41st week of 1996).

45. Check tire pressure frequently. Michelin and most other tire manufactures have a free RV tire guide that among other things tells correct tire pressure for different axle weights. Use your actual weight to determine the correct pressure. If you do not know the weight, use the GVWR sticker from the motorhome manufacturer. Do NOT inflate to the pressure shown on the side of the tire-that represents the maximum the tire can hold and is rarely even close to correct. Each time you stop, it is a good idea to walk around the coach with a small hammer and “thump” the tires just like the 18 wheelers do (particularly the rear tires). A medium size ball peen hammer works well. You can also touch the tire to check it. If pressure is low, the tire will be hot.

46. Disposable latex examination gloves (100 for $6) are useful while dumping, fueling, checking fluid levels, hitching and unhitching toad, etc. They keep your hands clean and you are not storing old gloves with diesel and sewage on them in the coach.

47. Hose out the radiator every time you wash the coach. If mud or dust covers the side of your coach, that same air was sucked into the intercooler and radiator. This can cause overheating and/or poor performance from inadequate cooling.