Roof A/C Covers

Roof A/C covers need to be removed to service the A/C unit. I find a large percentage of the covers damaged because the screws were tightened too much when the cover was re-installed. The screws can easily be tightened to the point that they crack the cover around the screw hole. The screw only needs to be tightened enough to hold the cover in place.

I suggest putting a washer between the screw and the plastic cover. The washer will spread the contact point over a wider surface area and will help to minimize the possibility of cracking the cover. Once the cover is cracked, the vibration of the A/C unit and wind, while traveling, will result in further damage to the cover. If the crack becomes large enough, the cover can detach and fly off the roof during travel.

Inspect the cover for cracks. If they exist, repair them or add a large surface washer to provide good contact between the washer base and the A/C cover. In many cases, using the washer on a cracked cover will provide enough contact with the cover to hold it securely on the unit and minimize further cracking of the cover.

Leaking Ice Maker

Is your RV more than 6 years old? It might be time to replace the little rubber washer on the water supply connection to the ice maker. I recently found a leak at the water supply connection. Just a little drip, but enough to cause a problem long term. Chances are that your rubber washer has deteriorated enough to begin causing problems. If it hasn’t already, it probably will pretty soon. I found that my washer had hardened and deteriorated to the point that I had to dig it out of the connection.

Replacement is a pretty simple process:
1. Locate the water feed line to the ice maker.
2. Shut off the water supply to the ice maker. (or to the coach.)
3. Open a faucet and release water pressure.
4. Place a small glass or container under the fitting to catch water draining from the line as it is disconnected.
5. Disconnect the hose connection on the feed line.
6. Remove and replace the hose type rubber washer. (I used a polyethelene type that will be less likely to rot.)
7. Attach the water connection. (Be careful not to strip the threads on the ice maker side. These are usually plastic
and the line feed is probably metal.)
8. Turn on the water supply and check for leaks.

You are now good for another 5 or 6 years, if not more. Plus you don’t have to worry about that water leak for a while.

Hydraulic Cooling Fan Motors

Some RVs have hydraulic cooling fans. The good news is that these fans operate from the hydraulic system of the RV and do not require a fan belt or other source of power. The bad news is that they operate from the hydraulic system of the RV. My fans motors began leaking so I ordered the seal kits from Monaco directly. You will need the motor number and other identification information to order seal kits. Order before you start the job, it takes a while for the seals to arrive after the order and they are probably not available locally. (My motors are Sauer-Danfoss.)

More bad news, the seal kits were $60+ each (Rebuilt fan motors were over $300 for the pair. You don’t want to know that new motors were (over $600/pair.) However, the task of replacing the seals is very easy but a little messy. The ugly part of the seal replacement is that the multiple hydraulic lines must be disconnected. You will lose a large amount of transmission fluid from the reservoir unless you have plugs that you can insert into the hydraulic hose fittings. If you don’t have plugs, you are looking at about 4 gallons of fluid replacement. I purchased several sizes of male and female hose fitting plugs for the job. I blocked off the lines at end points on either side of the feed and return lines.

Motor removal isn’t too bad. I had to remove several support brackets then four bolts holding each fan motor in place on the shroud. The motors are a little on the heavy side, with the brackets in place, but they are easy enough to manage.

Once the motors are removed, remove the fan blades and clean them. I used a puller to pull the blade off the shaft. Be careful with the blades. Mine are plastic and can easily break if dropped or abused.

The seal kit contains two valve seals and a shaft seal. Remove the back from the motor and the valve seals are visible. Note that two seals are imbedded in the grooves for the backing plate. Remember which ones are on top and which ones are under them. They are two different colors so this should be easy to remember. Remove the old seals, replace the new seals. Make sure that the valve seals are pushed into the grooves. They seem to snap in place as you push them into the grooves. The shaft seal is simple and straight forward. Pull the housing off the shaft, remove the old seal and install the new.

Replace the housing. Replace the fan blade, reinstall the motor, connect the hydraulic lines, add fluid and check for leaks. You are good for another 6 or 7 years.

My replacement took about 6 hours total. Considering the RV service cost at about $100/hr, I feel my time was well spent. The job is simple, but a little messy. I can take messy at that price.


Don’t forget about those coach batteries. Check the water in the batteries on a routine basis. You also want to make sure the top of the batteries are clean and free of dirt and liquid. Check the battery box to make sure that you do not have a corrosion build up in the box. If you do, remove the battery, clean the box and remove any corrosion and rust. Paint the box or treat it to minimize corrosion and rust.

Battery terminal corrosion can be minimized by installing small battery post felt pads that are coated with a chemical to reduce corrosion. They do work and I highly recommend using them. When you clean the battery posts and terminals, check any wire connectors that attach to the terminal for corrosion and clean accordingly. Make sure that the box still
has enough metal to hold the battery before replacing the battery in the battery box.

If your battery box slides out, clean the slides and brush on a small amount of grease to minimize rust or corrosion build up. This will also make it easier to slide the box in and out. Paint or treat any rusty surfaces.

Regular maintenance will help prolong the life of the batteries and ensure that they are properly charged for use when needed. I keep a small battery maintainer (Costs less than $10. Harbor Freight has them for as low as $5) to keep my start battery properly charged. It is not a charger. It is a low voltage maintainer. This ensures that the coach start battery is ready when I need it.

I found that converting my D series coach batteries to 6 volt golf cart batteries increased the available power to the coach. I found two golf cart batteries that fit in the same foot print as one D series battery. The wiring diagram for the conversion can be found on the RVSurvey web site at under the More Info tab.

RV Shocks

Replacing the shocks on a large RV can be a daunting task when you look at the size of those replacement shocks. The RV shocks are much larger than a regular auto and require more effort to compress (gas shocks). The good news is that access to the shocks, in most cases, is easier on the RV than it is on the auto, however it is still difficult to see the wear points for the shocks which is usually at the bottom side of the shock bushing at the top of the shock and the top side of the bushing at the bottom of the shock. Those old shocks may still have some life in them, but the bushings at the top and bottom of the shock may be beaten to death. If you hear rattles coming from under the RV, you may be in need of new shocks.

Removing the old shocks and installing the new shocks will require some good leverage to push the shock up off the mounting bolt so that it can be removed and reinstalled. I found that by using a little muscle power, pushing up on the shock, after removing the bottom bolt, I could swing the shock away from the shock mount bracket. Removing the top of the shock was easy. Installing the shock at the top, first, then tightening the bolt holds the shock in place so that you can push up on the shock to compress it enough to push it into the lower mounting bracket. Using a bottle jack, with appropriate spacers under it, will make lifting the shock enough to get the lower bolt in place a lot easier.

I chose to do the front four one day and the back four another. A big job but the new ride is really worth the effort. Besides, the money I saved doing it myself paid for dinner for the wife.

A/C Air Filters

Air conditioner filters in the RV are often overlooked for replacement because, after all, the RV only gets pulled out when you are ready to use it. Unlike the home air filters that are routinely changed every several months on a regular schedule.

The air conditioner filters in the RV do need to be replaced periodically. Next time you are in the RV, take a quick look up at the ceiling air intake to see if it is time for replacement. The replacement material is inexpensive and can usually be found at your local home improvement store.

While checking the filters, look at the ducts to see if they should be cleaned. Also, check the operation of the metal or plastic vents to make sure they have not frozen in place. If there is any rust present, pull them down, sand them and repaint them to get them fully reconditioned.

Wiper Blades

On a recent trip I noticed that the wiper blades were not tracking to the same location on the window that I was used to seeing. On further inspection, I noticed that the screws holding the wiper blade assembly to the front of the coach and the wiper motor were loose. A quick tightening of the screws anchored the assembly to the motor and the blades were back where they needed to be. It is probably a good idea to check the mounting screws occasionally just to make sure they are tight and have not worked loose.

It is also probably a good idea to check the condition of the wiper blades to make sure they have not dried out and cracked from exposure to the elements. It is much better to replace the blades on a nice day than it is to have to do the job when it is raining when you need them to be working properly. Look at the wiper blade assembly to make sure that the assembly is securely attached to the wiper arm. Look at the windshield washer feed lines to the wiper blades is attached to the wiper arm.

While there, check the level of windshield washer solution to make sure you have plenty for that next trip, just in case you may need it.

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Vehicle Tow Bars

Several times I have not been able to easily get my tow bar to lock after it is attached to the tow vehicle. I use the Excalibar tow bar. I really like it. I usually connect the bar, back the tow vehicle until the bar locks with a click. This usually only locks one side. I count on pulling the coach forward to pull the other side into the locked position.

I tried using a lubricant on the slider bar (rod), and that worked for a while but then stopped working. I found that it worked much better when I used a solvent (WD40) to clean the rod. I spay the rod then wipe it clean. I have found that the bar seems to work much better when clean than when it has a lubricant on it. The lubricant seems to pick up road dirt and the dirt works its way into the lock mechanism. So, if you are having this type of problem, try cleaning rather than lubricating the tow bar rods.

One more thing to check. Be sure to periodically check the bolts in your towed vehicle tow brackets. I recently heard a horror story about an RVer that arrived at his destination to find that his towed vehicle was not with him. The bolts may work loose, so check to make sure all bolts are tight and the tow bar is securely attached to the RV.

A/C Unit Maintenance

An often forgotten part of routine RV maintenance is the roof A/C unit. The unit should be cleaned and checked at least once a year. A good time to do this maintenance is early in the season to ensure that the A/C unit is in top operational condition for those hot summer days.

Remove the A/C cover and use a wire brush to gently clean the evaporator coil fins. It looks like a small radiator. The brush will remove dust and dirt trapped between the cooling fins and around the coil. Using compressed air, blow the dust from the inside of the unit to the rear, working up and down the evaporator.

Check the motor to see if it has an oil fill port to lubricate the fan shaft bearing. Some units are permanently sealed and will not have the tube to add oil. Put a few drops of oil down the tube and replace the cap. This will help keep the bearings properly lubricated and will avoid potential problems with the motor seizing or the bearing to fail.

Check the cover for needed repairs due to cracks or damage around the attachment holes. Repair as necessary. Most covers can be easily repaired if they are caught before the cover is too badly damaged. Replacement covers can be purchased but they are not cheap.

Window Screens

Have you checked those window screens lately? Do they look a little dusty? Does it look like the holes might be filling up with dust and dirt? Well, maybe it is time to think about cleaning them, before the next trip.

It is best to remove the screens to be able to give them a thorough cleaning. Many RV’s don’t make it easy to remove the screens without damaging the screen frame, so you may have to resort to cleaning them in place. Either way, the end result is a clean window screen that looks better and lets more air flow through the window.

I have had good luck cleaning the screens in place by first wiping the screen with a soft cloth sprayed with Endust. It doesn’t remove all the dust and dirt. I then follow with a soft cloth dipped in a solution of water and cleaner (409 or equivalent). This step removes most of the remaining dirt and dust. I follow that with a dry soft cloth to remove the dirty water/cleaning solution. If the screen looks as though it has streaks, I just repeat the damp cloth process followed by the dry cloth.

Those clean screens sure look nice and they let more air flow through the RV.

Windshields Damage and Repair

One of the more expensive repairs on RVs is windshield replacement. It is very important to take time to look closely at the front windshield during the inspection process. Some cracks and chips are difficult to see from the outside. During your inspection process, look at the windshield from several angles during the outside inspection. Make a note of the location of the chip or crack. Go inside the RV to look at the windshield from several angles. You may see defects that you did not notice during the outside inspection. I have noticed that some cracks, especially those at the curve of the windshield are difficult to see unless you look from different angles. I make a special effort to view the windshield from both the passenger and drivers side of the RV. Cracks near the seal are also difficult to detect. Look closely around the seal edge of the entire windshield. A small crack or chip today may be a large crack a few months later.

Some cracks and chips can be repaired. A rock chip is easier to repair than is a crack. If the crack is caught early, it may be stopped by drilling a small hole at the end of the run. Most windshield repair services will not guarantee that the run will be stopped and often warn that the attempt to repair it may result in the crack running further. Chips are much easier to repair. If caught before water enters the hole between the glass layers, repairs can be effective and permanent.

Since the windshield replacement cost is so expensive, factor the replacement cost in the final purchase price of the RV. You should include the cost of replacing the seal as well. I recommend having a new seal installed when a new windshield is installed.

Many newer RVs have single pane windshields. These will cost much more than the two panel windshields, so look carefully for damage.

RV Tire Condition and Age

Tires are a critical component to check during a pre-purchase inspection or routine maintenance. One thing I often find during a RV inspection is old tires on vehicles being sold. RV tires seldom wear out due to high mileage. Many RVs being sold have original tires. When low mileage RVs are sold, the original tires are still on the RV. General tire literature recommends replacing tires after six years.

Tires installed on the RV new are usually older than the RV itself. The tires come out of stock that may be months or more older than the RV. One of the ways to determine tire age is to look at the DOT stamp on the tire. Following the DOT stamp are a series of numbers inside small ovals. The last oval contains the date information for the tires. For example, 337 would indicate that the tires were manufactured in week 33 of 1997. Beginning in 2000, you will find four numbers. The first two are the week of manufacture and the last two are the year of manufacture.

Tires are designed to roll. The rubber compound has been designed to create a lubricating effect within the rubber compound when the tires are rolling and at operating temperature. Using the tires (and RV) is a good thing because it keeps the rubber lubricated and pliable.

I often see very low mileage RVs with tires that have excellent tread but show dangerous signs of tire rot. Outside exposure decreases tire life when the tires are stationary for a long period of time. Tires stored inside will also show signs of tire rot over time if they are not used.

The key message is use that RV and keep checking the tires for cracks around the sidewall. Be prepared to replace the tires around six years, regardless of the amount of tread remaining if you see cracks forming on the side wall of the tire.

Roof Vent Caps

During routine RV inspections, I often find damaged plumbing vent caps on the plumbing vents. The roof is often neglected during normal use and maintenance. The poor old roof vents are battered by low lying branches and other low hanging objects and are often ripped off the roof or broken to the point that they are no longer functional. The plumbing vents need caps on the vents to keep water and other debris from entering the vent lines and eventually the holding tanks. It is a good idea to climb up the ladder to check the roof for damage on a regular basis. Even if you don’t bother to wash it, which you should, go up to check on the condition of the roof vents and other components attached to the roof.

Roof vent replacement caps are very inexpensive but are still a critical part of the RV plumbing system. Take the time and make sure that yours are still in good shape. If pieces are missing, replace the vent cap.

Engine Drive Belts

Check engine drive belts on a routine basis. A logical time is when you are servicing the RV or ready to take it in for service. Look specifically for small cracks, worn or frayed edges in the drive belts. While looking at the belts, check for proper tension.

I prefer to carry a replacement drive belt on my coach. I don’t want to be in a place where I cannot have a replacement available for that emergency repair. Whether I do the job or have a roadside service replace the belt, I want to make sure I have the right one installed. Some RVs have special drive belts that are not readily available and in stock. Specialty belts may have to be ordered, so plan ahead.

That said, if you plan to make the emergency or routine replacement yourself, make sure you have the necessary tools on the coach.

Fuel Lines

If your motor home is older than 5 years, be sure to check the rubber fuel lines. These lines can deteriorate over time and become hard, cracked and easily broken under the pressure provided by the fuel pump. Diesel or gas, it doesn’t make any difference. Check to make sure that the fuel line is not rubbing against any engine component, especially the engine block where it could be subjected to heat from the engine. Rub the line to feel for soft spots or bubbles. If you rub the line and you get black rubber soot on your hands, it may be a sign that it is time to replace the line. The cure is rather inexpensive, compared to a potential fire or road side repair that may cost much more.

It is a good idea, as part of your routine maintenance, to check around the engine to see if fuel lines are leaking.

Rear Wheel Oil Seals

One of the key inspection points most buyers miss is one of the easiest to problems to detect. It is checking the rear wheels for signs of an oil seal leak at the rear axle. The signs of a leak are easily seen on the inside of the rear wheel or the brake back plate. If oil is detected, there is a high probability that oil has leaked onto the brakes and brake components, creating a very messy repair project inside the brake drum. The problem with not fixing the problem is the potential for brake failure or a fire.

Take the time to inspect the rear wheels before and after you buy that RV. A quick look on the lot or at home may save you problems down the highway.

Roof A/C Covers

I have been noticing a lot of A/C covers cracked around the lower edges and at the mounting holes where the screws are attached. It is important to make sure that the covers are securely attached, but it appears that many owners (or repair shop personnel) are tightening the screws too much so that they cause the cover to crack. Use caution and less muscle when attaching the cover.

It is also important to inspect the covers from time to time to make sure that any cracks in the cover are not growing. I have had success repairing the plastic covers with fiberglass cloth and fiberglass. The repair kits can be found in most automotive parts departments. The repair doesn’t take long and the fiberglass hardens very quickly. I make all repairs on the inside of the cover so the repair is not seen when the cover is installed.
Instructions for preparing the surface to be repaired and applying the glass and resin are provided with most repair kits.

If the cover is already cracked around the hole, you might save the cover by adding a large surface washer under the screw to spread the force of the screw on the cover. This will work if the crack has not spread too far.

If the cover is damaged and not repaired, the wind force may further damage the cover due to vibration and eventually allow the cover to be blown from the roof of the RV. Replacement cost may be around $100.