This post may contain affiliate links, please read our affiliate disclosure to learn more.
A person looking and fixing an engine

DIY RV Maintenance Fluids and Filters

Updated on February 4th, 2024

Knowing RV maintenance fluids and filters is part of owning a recreational vehicle, but if you own a motorhome, you’ll have more to add to your to-do list because you’ll need to keep the engine running smoothly.

Luckily, motorhome engine upkeep doesn’t need to interfere with your camping and travel plans. You can save money and time maintaining your motorhome engine by changing fluids and filters yourself.

To make it simple, we made this guide to DIY motorhome engine upkeep that details what engine components need routine maintenance and walk you through how to change or check your motorhome’s oil, fluids, and filters.

Most motorhome engine upkeep isn’t difficult or time-consuming, so take a few moments to learn how so you can keep rolling through your camping season!

Motorhome Engine Maintenance Checklist

To maintain your Class A, Class C, and Class B motorhome properly, you first need to know which engine components need routine upkeep, which ones you can DIY, and which ones should be left to the experts.

Motorhome engine problems being fixed

You will also need to tailor this list to your model of RV, as diesel and gasoline motorhomes may use different parts or fluids. As you work through this guide, it’s helpful to write down all the brands, sizes, and types of fluids and filters your motorhome needs to streamline your shopping and always have the products you need on hand.

Plus, it would be best to remember that the first time you perform these tasks, it will take a bit longer as you learn the method, but future upkeep will be easier and faster.

Here are maintenance tasks you can DIY in your motorhome:

  • Oil change
  • Oil filter change
  • Windshield wiper fluid
  • Air filter
  • Power steering fluid
  • Brake fluid
  • Radiator fluid
  • Transmission fluid
  • Hydraulic oil for leveling jacks

Motorhome Oil and Oil Filter Change

Supply list:

  • Oil collection pan
  • Quarts of oil for your RV (consult owner’s manual for type and amount)
  • The replacement oil filter (consult owner’s manual)
  • Oil filter wrench
  • Torque wrench
  • Rags
  • Plan for old oil disposal

For RV maintenance, fluids and filters, Every motorhome engine will require a specific amount of oil to run. For example, some RVs may need only eight quarts, while others may need over 25 quarts! Ensure you have a large collection pan to handle your needs because you don’t want to spill oil on the ground.

Step 1: Park your RV on a flat surface and run the engine for five minutes to warm up the oil so it will flow out easier. Turn off the RV and loosen the oil fill cap inside the engine compartment.

Step 2: Position the drain pan under the oil drain valve on the underside of your RV. Remove the small plug from the oil pan, and allow the old oil to drain fully.

Step 3: Change out the oil filter. Place a pan under the oil filter if the larger oil collection pan will not reach. A bit of oil will drip out when you change the filter. Use an oil filter wrench to make removal easier.

Once the filter is out, use a clean rag to wipe the oil residue off the seat. Next, rub a bit of oil around the rim of the new filter, put the new O-ring on, twist the new filter into place, then use the wrench to tighten it up.

Step 4: Reinstall the drain plug using a torque wrench to ensure it’s tight enough without stripping the threads (information on how much torque is necessary will be in the owner’s manual) so it won’t leak.

Step 5: Refill the new oil at the filling port in your engine compartment. Use the exact amount, type, and weight of oil the RV manufacturer recommends, then close the filling cap. A funnel will help keep oil from spilling onto other engine components.

Step 6: After a few minutes, peek at the oil pan drain plug and filter for drips. Tighten the filter or plug if necessary. If there are no leaks, start the motorhome and let it run for ten minutes, then let it cool down for 30 minutes.

Step 7: Return to the oil fill port and use the dipstick to check the oil level. It should read at or close to the full mark. If the level is low, add more oil in small increments until you reach the full mark. Close the fill cap, and you’re good to go.

TIP: Overfilling the oil level can ruin your engine because the oil will be in contact with the crankshaft. If you see the oil is above the “full” mark, you’ll need to drain off the excessive oil from the pan by removing the plug.

Motorhome Wiper Fluid

Supply list:

  • Windshield wiper fluid of choice
  • Funnel

Refilling window washer fluid is very straightforward. First, locate the reservoir in your engine compartment. The top will have a large port with a rubber or plastic cap you will open.

Drop in a funnel, and add fresh fluid until you reach the fill line. Do not overfill because the reservoir needs space for the fluid to expand under hot conditions.

Motorhome wiper fluid being poured into the engine

The type of washer fluid you use can make driving your RV easier. For example, you can buy a “bug cleaner” version with special enzymes to rid the windshield of sticky bug residue or an orange washer fluid with chemicals that will de-ice the windshield during cold-weather camping.

Air Filter

Supply list:

  • Air filter replacement
  • Tools to remove air cabin filter cover

For RV maintenance in fluids and filters, you’ll want to change your RV air filter about every 12,000 miles, and your owner’s manual will pinpoint the housing location in either your main engine compartment or, in some motorhomes, it will be in the driver’s cab area under the doghouse.

You can locate the information about the size and type of air filter from the manual, or you can remove the old one and use the specs to purchase a new one. Don’t skimp on the filter price to save a few bucks. The air filter will remove contaminants and keep your engine running more efficiently.

Changing out the filter is easy. Just ensure you place it into the compartment in the right direction (look at the arrows or info on the filter), so the airflow is correct.

Power Steering Fluid

Supply list:

  • Power steering fluid type for your motorhome engine (see manual)
  • Funnel

Topping off your RV power steering reservoir is another easy DIY project. First, ensure you are using the appropriate brand or type of fluid, which you can find in the motorhome owner’s manual, and often, the stats are listed right on the reservoir cover.

Locate the power steering reservoir and open the cap. Pull out the dipstick, wipe it with a rag and reinsert it. Next, remove the stick again and read the level near the bottom of the stick. Add fluid if it’s below the “max fluid” level indicator.

Brake Fluid

Supply list:

  • Brake fluid (see manual for type/brand)
  • Funnel

Checking your brake fluid in a Class A or Class C motorhome or a Class B campervan isn’t always easy, as the reservoir is often in a hard-to-reach place. Diesel pushers do not have a brake fluid reservoir because they use air brakes.

Use your owner’s manual to locate the position of your brake fluid reservoir, which will have lines on the outside indicating the minimum and maximum amount of fluid it should hold. If the level is low, add fresh brake fluid until it hits the maximum line.

Brake fluid should be clear with a slightly yellow tint. If the fluid is opaque or dark brown, you’ll need to take the RV in for a complete brake fluid flush.

Radiator Fluid (Coolant)

Supply list:

  • Coolant type for your motorhome engine (see manual)
  • Funnel

Radiator fluid helps keep your engine and transmission cooler and includes chemicals to prevent freezing in the lines during winter, so it’s imperative to keep it full.

It takes a long time for the fluid to evaporate, so it generally will be at a good level when you check it. However, always add coolant immediately if you see the engine temperature gauge on your dashboard climbing.

Before you start, ensure your engine is cool. Never try to open a radiator cap if it is hot.

Locate the radiator in your motorhome, and a cap should be on top to add fluid. Before you open this cap, locate the radiator fluid overfill reservoir in the engine compartment.

Often, this reservoir has a cap for you to pour in additional coolant if the level is low. The plastic on the reservoir will allow you to see the contents inside, and the sides will have a “fill” or “full” line marking so you know when to stop adding fluid.

If you must add fluid directly to the radiator, remove the cap by pressing down and twisting. Add coolant to the fill line indicator. Replace the cap.

Start the engine and listen to it hum. If you hear anything strange or spot any leaks, you’ll need to take your RV to a service center for further investigation.

Checking Radiator Level (Video)

Transmission Fluid

Supply list:

  • Transmission fluid type for your motorhome engine (see manual)
  • Funnel

Topping off the transmission fluid and filters in your RV maintenance can be done when the dip shows it is low. Some RVs have a separate port to add fluid, while most will require you to add it through the small tube where the dipstick inserts.

Experts recommend checking the tranny fluid after a short drive, so the engine is warm. Then, park the RV on a level surface, pull the dipstick, and wipe it off. Next, reinsert and check the level, which should be within the crosshatched markings or line indicators.

Use a funnel to pour more fluid if necessary, adding it slowly to prevent backups.

Hydraulic Leveler Fluid

Supply list:

  • Low-viscosity hydraulic oil (see manual for type/brand)
  • Funnel
  • Manual siphon pump

If your motorhome comes with automatic hydraulic levelers, you’ll need to check the oil level in the system to ensure the jacks work correctly. You can top off a low fluid level, but you’ll want to change all the fluid every two years.

In most cases, the reservoir for the oil is hidden inside a front exterior bay or to the side of the engine compartment, which you can confirm by referring to the owner’s manual. The reservoir holds about a gallon of fluid.

Before you check the hydraulic oil level, ensure the RV is on an even surface, the slideouts are in, and the leveler jacks are up.

The type of reservoir you have may vary, but it should have a plug at the top and a “full” indicator line on the side, while some may have a dipstick to check the fluid level. If you’re just topping off the fluid, you can use a funnel and pour enough hydraulic oil in to hit the full mark.

When you need to change all the hydraulic fluid, you’ll need to use a manual siphon pump and place one end inside the reservoir and the draining end into a canister so you can dispose of it properly later.

You pump the siphon handle to draw out all the fluid. Once done, switch the location of the tubes and place the suction end into your fresh hydraulic oil container and the drain end into the reservoir in your motorhome. Pump the siphon to transfer the fluid into the reservoir until it hits the full mark.

Hydraulic Leveler Fluid (Video)

RV Maintenance Wrap Up

The more RV maintenance tasks you can DIY, like fluids and filters, the more confidence you’ll have in keeping your motorhome in tip-top condition between routine tune-ups. Saving time and money by doing motorhome oil changes and other jobs yourself is another bonus that further extends your RVing budget.

With good notes on which products and supplies you need and a bit of experience, you’ll soon master the motorhome fluid and filter changes we detail above, so you can keep those camping adventures rolling!

Related Questions

  1. What are the essential tools needed for DIY RV maintenance?

The essential tools needed for DIY RV maintenance include a basic tool kit with items such as screwdrivers, wrenches, pliers, a hammer, and a multi-meter for electrical work.

Additionally, it’s important to have RV-specific items like a sewer hose, water pressure regulator, tire pressure gauge, leveling blocks, and a portable waste tank.

  1. How often should the various fluids and filters in an RV be changed?

The frequency of changing fluids and filters in an RV depends on various factors such as the type of RV, its usage, and the manufacturer’s recommendations.

Generally, engine oil and filter should be changed every 3,000 to 7,000 miles, transmission fluid every 30,000 to 60,000 miles, coolant every 2 to 5 years, and air filters should be replaced annually or every 12,000 to 15,000 miles, but always refer to your RV’s specific owner’s manual for the most accurate information.

  1. What are the potential risks of not properly maintaining an RV’s fluids and filters?

Not properly maintaining an RV’s fluids and filters can lead to severe mechanical issues, such as engine damage, transmission failure, and brake system malfunctions, which can result in costly repairs and unsafe driving conditions.

Additionally, neglecting regular maintenance can significantly decrease the lifespan of the RV, affect its performance, and potentially lead to breakdowns during travel, causing inconvenience and potential danger.

  1. Are there any specific brands or types of fluids and filters that are recommended for RVs?

Yes, there are specific brands and types of fluids and filters recommended for RVs. For engine oil and transmission fluid, brands like Mobil 1, Shell Rotella, and Valvoline are often recommended, while for filters, brands like WIX, K&N, and FRAM are popular choices due to their reliability and performance.

  1. What are some signs that an RV’s fluids or filters need to be changed?

Some signs that an RV’s fluids or filters need to be changed include unusual noises, decreased performance, or visible leaks. Additionally, if the fluid is darker than usual or the filter is visibly dirty or clogged, it’s likely time for a change.

"Of all the paths you take in life, make sure a few of them are dirt."
-- John Muir
Scroll to Top