Maintenance Tips

The maintenance tips below are provided by our service experts to help you keep your RV motorhome chassis in tip-top shape.



Maintaining Correct Tire Pressure

by Mike Cody, Sr. Service Trainer
Freightliner Custom Chassis Corporation

The most important factor in maximizing the life of your tires is maintaining proper inflation pressure. An under-inflated tire will build up excessive heat that may go beyond the prescribed limits of endurance of the rubber and the radial cords. Over-inflation will reduce the tire's footprint on the road, reducing the traction, braking capacity and handling of your vehicle. An over-inflated tire will also cause a harsh ride and uneven tire wear while being more susceptible to impact damage.

Keep in mind that the pressure rating on the sidewall of your tire is the maximum pressure for that tire. This is not necessarily the correct pressure for the tires when installed on your vehicle. Maintaining the correct tire pressure for your vehicle's loaded weight is extremely important and must be a part of regular vehicle maintenance.

It’s recommended that you check your pressure at least once a month, before any major trips, and before and after storage. On long trips, check every morning before driving. For shorter trips of a day or less each way, check the pressure before you leave and before you return home.

To set the correct air pressure for your tires:

1. Get a copy of the Michelin Recreational Vehicle Tire Guide or Goodyear Recreational Tire and Care Guide as appropriate for your tires

2. Weigh each wheel position on your RV:

A. Load your motorhome as you would normally travel, including water and fuel.

B. Weigh EACH WHEEL POSITION independently, with driver and passenger or passengers in the vehicle as described in the tire guides, to determine the weight on each wheel. While truck stops have scales, most will not allow you to pull half on and half off to get all your independent wheel weights. Front and rear axle weights do not provide adequate data; you must find a scale that will allow you weigh each wheel position independently.

3. Use the charts in the guide to determine the correct inflation pressure based on your tire size and load weight. Pressures are given for a single axle (1 tire on 1 side of a single axle) and double axle (2 tires on 1 side of a dual axle).

4. Adjust each tire’s pressure accordingly.

NOTE: For control of your motorhome, it’s critical that the tire pressure be the same on both sides of the axle. You will need to inflate both tires on a single axle to the pressure indicated for the heaviest wheel position on that axle.

NOTE: Only adjust pressure when the tires are cool or have not been driven for more than one mile. Never reduce the air pressure in a hot tire!

Camping in Remote Areas

When camping in remote areas, check the engine compartment for small animals that may have taken refuge for the night before starting your engine. they like the warmth of the engine compartment but will make a real mess if you start the engine while they are nestled in the fan shroud.

RV Storage

Use our handy checklist to make sure your motorhome is ready to be put into and removed from storage.

Radiator and Charge Air Cooler Maintenance

On chassis equipped with a rear radiator, it is very important that the radiator and charge air cooler be inspected at regular intervals. Cummins® recommends inspecting the charge air cooler every 7,500 miles. This is because air and dust blown through the radiator and charge air cooler can build up and reduce the airflow through the cooling system. This is considered part of normal maintenance.

From the engine side of the radiator, use a flashlight to look into the fan shroud at the face of the charge air cooler. If there is any dirt buildup, this should be cleaned using a water hose and a mild solvent. If this is not done, the system can become clogged and can result in engine overheating.

Tire Dressing

We recommend not dressing your RV tires, as it will strip the tires' rubber of their UV protection.

Replace Air Dryer Filters

Air dryer filters should be replaced every three years. You may have to request this work. Chassis prior to 2003 have an 18 month interval. Questions? Call 800-FTL-HELP

Ride Height Adjustment

The ride height is the setting for the air suspension on your chassis. If the ride heights are not set properly, two important factors are affected:

1.) The front ride height will change the front-axle caster settings. This can affect the handling of your coach on the highway and tire wear.

2.) The rear ride height will change the drive-shaft angles. Incorrect drive-shaft angles can cause driveline noise (vibration or a growling sound) and can cause premature wear of the u-joints on the driveline.

On XC chassis, the ride height should be checked at each scheduled maintenance interval. This is every twelve months or 15,000 miles, whichever comes first. We recommend you have ride heights checked at an authorized Freightliner dealer, or purchase a FCCC Workshop manual from an authorized dealer for proper ride height checking and setting information.

Air Brake System Draining

Air reservoirs serve as storage tanks for compressed air. They collect water condensed from the air, and small amounts of oil normally enter the reservoir in the form of vapor, because of the heat generated during the compression. After the water and oil condense, they collect near the tank drain valves and should be drained regularly.

If the air tanks are not equipped with automatic drain valves, you should drain the tanks daily during vehicle operation.

If they are equipped with automatic drain valves, they should still be drained manually every six months during operation. To drain the tanks, pull the three drain lanyards provided until all moisture is expelled.

Maintenance Checklists

Print a routine maintenance checklist and take it with you to service appointments to have your dealer verify services performed.

For a full maintenance schedule, see the online XC and SL maintenance manual or S2 maintenance manual.