American RV motorhomes are complex machines, and like any other complex machine, they need regular maintenance. When I refer to regular maintenance, I don’t just mean an oil and filter change; I am talking about a thorough inspection conducted by a team of qualified engineers.
One of the problems with American RV motorhomes is that they are not very fuel-efficient. Some owners try to take the easy option, which is to get them repaired and serviced at their local lorry workshop. Although the lorry/HGV/LGV engineers are qualified, they are not familiar with many of the American motorhomes’ equipment. They may be quite capable of servicing or repairing the engine, but might struggle when inspecting the gas fridge or water boiler. Would they know what product to use to reseal the roof? One way of looking at it is that you could be paying someone to learn how to repair your American RV motorhome.
At AMS, we take pride in our extensive knowledge of American RV motorhomes, which in itself goes a long way in offering customers preventative maintenance and trouble-free RVing.
We work from a time-evolved service sheet. When a potential problem arises more than once, we can then monitor the situation. If a problem occurs more frequently, it will be included in the service.
One operation that we included on our service sheet when it was devised was the removal of the road wheels. This was to enable us to gain access to the brake material. Most American RV motorhomes with the engine at the front have disc brakes, while those with the engine at the rear often have drum brakes. If, when inspecting the motorhome, we see a blue tinge on the brake disc, it alerts us that the brakes may have been getting too hot. With this now in mind, we will then check the water content of the brake fluid. If the content were above 1%, then the fluid would need to be changed; however, this could also be an underlying factor for why the brake disc was in this condition. Without removing the wheel and gauging the thickness of the brake pad or brake shoe, most inexperienced people would not realise that a brake disc with a blue tinge and a high content of moisture in the brake fluid might be a manifesting problem.
The discoloured brake disc
If the vehicle is 10 years old and has only covered 17,000 miles, some inexperienced people would assume that with that mileage on the clock, the brake shoes would be fine and there would be no need to remove the wheels.
When a motorhome has covered such low mileage, most owners automatically think this is a positive thing; however, a motorhome that has sat still for long periods can deteriorate quite badly. Take the moisture in the air, for instance; it will attack the brake pad material and cause it to crumble away. If the road wheels and brake callipers are not removed, then this cannot possibly be detected.
The moisture in the air has caused the metal backing of the brake pad to corrode, which in turn has led to the failure of the adhesive between the backing plate and the brake pad material. This problem can happen with the brake shoes found in drum brakes. The metal brake shoe corrodes on the surface to which it is attached; this corrosion builds up under the brake shoe and forces the shoe upwards, putting pressure on the brake rivets. If this corrosion gets too severe, the excess pressure on the brake shoe rivets can cause them to come loose. Another problem that can occur is that corrosion takes place under the end of the brake lining, lifting the lining and causing it to crack and break off.
Another reason to remove the brake drums is that the brake dust generated by brake lining wear will accumulate on the surface of the brake shoe. This dust falls into the brake shoe rivet holes, and the build-up of dust then becomes compressed between the brake shoe and the drum. In extreme cases, this build-up of dust in the brake rivet holes becomes higher than the brake lining itself. The result of this is that the braking efficiency is lowered. The next step is to remove the brake dust from the rivet holes.
American RV motorhomes with air brakes have a device called an air dryer. On top of the air-dryer is a canister braking, like a larger oil filter. This canister needs to be changed every few years. The purpose of this canister is to house desiccant. This desiccant is housed in a textile bag, which, with age, will deteriorate, allowing the desiccant beads to enter the air brake system, causing damage to the air valves. Even if this didn’t happen, once the desiccant reaches the end of its useful life, it cannot absorb any more moisture. This moisture will then enter the braking system, and in winter, it could freeze.
In the picture, you can see that the desiccant filter has not been changed for some time.
American RV motorhomes require a Class 4 MOT once they reach three years old. The Class 4 MOT is identical to the test carried out on family cars. Now that the MOT requirements have changed, a lot more checks have been included. One that has now been added is the inspection of ball joint dust covers. Most modern cars have sealed ball joints, which means they have no way of greasing them. Once the dust cover is damaged, water can enter the ball joint, and the small amount of lubrication used will quickly be diluted, accelerating the wear process of the ball joint.
The later workhorse chassis RV motorhomes did use sealed bottom and top ball joints, so I would tend to agree with the VOSA theory. However, the older version used a greaseable ball joint, which, to my way of thinking, should not apply because if regularly serviced, any water entering the ball joint dust cover would be forced out when re-greasing the ball joint. The only saving grace is that you can replace the dust covers without having to purchase another ball joint. I have replaced a fair number of the sealed bottom and top ball joints when they have become well-worn. It’s not worth spending the time to remove them from the stub axle to replace the rubber boot because the wear process is quickly accelerated when water is allowed to enter the ball joint cup and ball.
Other items we check on the service can save lives. The number of 230-volt electrical problems we encounter that are down to a lack of knowledge is quite frightening. Qualified electricians have completed some of this work, and if that is the case, all I can assume is that they are so used to wiring up houses that they are now totally out of their comfort zone. One common problem is the use of incorrect gauge wire (thickness). This is a common problem when wiring up transformers. What happens is the same gauge wire is used to feed the transformer as to exit the transformer.
Let me explain – If you are lucky, they might use 1.5mm diameter flexible cable, but more often than not, they go for rigid cable as it is less expensive. The transformer is fed with a 1.5mm cable capable of safely carrying 16 amps at 230 volts; the same diameter cable is used to exit the transformer. If you half the voltage and double the ampage, this is the formula all electricians should know. The cable exiting the transformer needs to be twice the thickness, in this case, capable of carrying 32 amps safely.
The real hard facts are that the vehicle was plugged into a 13-amp socket in our workshop. As we were testing the air conditioning, we smelt burning and traced the smell back to the transformers.
Damp testing inside the vehicle is also crucial. If these problems are detected early, a re-seal of the roof can be performed to stop water ingress, thereby avoiding significant problems and expense.
Other problems that can occur and can in a lot of cases be avoided are when owners tell me their vehicle has not covered many miles, quoting “I have only used it twice this year, so you can inspect the RV, then take it for an MOT”, then the following year I get the same request. In the third year, I might get “You better give the RV a service as I haven’t had a service for a while.” This could mean the vehicle has not had a proper in-depth inspection for a total of three years.
In a real-time case, this occurred, and upon inspecting the roof, we found that something had impacted the TV aerial, which had subsequently damaged the seal between the aerial and the roof. Water had then leaked under the TV aerial. If the vehicle had been serviced at yearly intervals, the damaged seal would have been spotted and then re-sealed, preventing any further damage. Unfortunately, this was not the case, as you can see in the images, the water has spread under the rubber membrane. The damage was severe enough to warrant replacing the wood and some of the membrane.
Another check that is carried out on a service is to check the air conditioning gas pressures. A vehicle’s air conditioning system, which is powered by the engine, will consume a small amount of fuel each year. This gas will escape from the pipe joint, primarily from the compressor seal. Some customers, when informed that the system requires some gas, reply, “We don’t use the air conditioning because the weather is too cold!” The simple fact is that the air conditioning system removes water from the air when working correctly; this is a huge advantage when you need to demist your windscreen. For those of you who are new to RV, motorhoming might not realise what happens on a damp rainy day. It isn’t easy to eliminate condensation from the inside of an American RV motorhome’s windscreen without the aid of air conditioning, due to the size of the windscreen. The air conditioning is automatically activated when you direct the heater motor airflow to the windscreen. Taking into account all these facts, I personally think that adding more gas to the system is more about safety than comfort.
Batteries
Checking the batteries is also included in the service. If the batteries have a removable top, we will check the water level and inspect for any distortion before topping them up with distilled water. The battery voltage of the fully charged batteries is noted, which can give us a good indication of the battery’s condition.
One of the main problems found is not with the batteries but with the battery charger. Some of the original battery chargers only charge the batteries at 13.6 volts, which can be a leading cause of sulfation and premature battery failure. To charge the batteries to their optimal level and get the best from them, the charge voltage should be as close as possible to 14.4 volts. This will give you a 100% charged battery, unlike the 13.6 volt, which will only give you a 75% charged battery, as well as reduced battery life due to sulphation.
Tyres
On our service, we will also check the tyres when the wheels have been removed for brake examination. There is more to a motorhome tyre than the depth of the tread. Tyre ageing is a big issue with any vehicle that is not used frequently or that has been left in storage. First of all, we examine the date stamp; the four-digit tyre code is usually located in a window on the tyre wall.
In the example above, you can see 0417. The first two digits of the code represent the week of production during the year (from 1 to 52), and the second two digits represent the year of manufacture. In this case, the 04 stands for the fourth week of the year, while the 17 is the year in which they were manufactured. If your tyres are printed with only a three-digit number, it means that the tyre was manufactured before the year 2000 and should be replaced as soon as possible. Cracks around the side wall of the tyre can identify tyre ageing. This is brought about when ultraviolet light from the sun oxidises the rubber, causing it to dry out. At the same time, tyres contain anti-oxidising chemicals that significantly slow down the rate of ageing. This wax-like substance, which is often referred to as soap, is only released when the tyre is in motion. This explains why a tyre that is badly cracked is usually light grey in colour. If the tyre is not used frequently, it will age more quickly, making it, in some cases, unroadworthy. This is why, we carry out these checks, because many RV owners assume that because their vehicle has low mileage, the tyres will be in good condition. Looking at the tread depth would confirm this. It is not until you start to look carefully that the situation begins to change. Owners often assume that the tyre is in good condition if it has plenty of tread and do not realise that this can become a safety issue for you, your family, and other road users.
Tyre Pressures
American RV motorhomes have a data plate attached to the inside of the body. This is usually positioned on the wall above the left-hand arm of the driver’s seat. On this plate, you will find data such as the chassis number and body number, along with other helpful information. Somewhere in the middle of the plate, you will find the recommended tyre pressures.
Here are a couple of points about the recommended tyre pressures.
1. The recommended tyre pressure would only be related to the original tyres, not the tyres you have fitted now.
2. Americans do not have many roundabouts or corners, which allows them to run on lower tyre pressures as tyre shoulder wear is not an issue.
3. Americans do not have to suffer the potholes in the roads as we do; again, they can run on lower tyre pressures.
First, look at all the tyres to ensure the tyre pressures stamped on the tyre wall are the same.
The tyre pressure is stamped on the sidewall of the tyre. Then we examine the maximum load rating of the tyre, ensuring that the load rating is sufficient for the motorhome’s gross axle weight rating (GAWR).
The top number, 3150 kg, relates to a single tyre (front), and 2900 kg relates to dual tyres (rear).
On this data plate, we can see that the front gross axle weight rating is 2,495 kg, and the rear is 4,563 kg. On an AMS service, we ensure that all tyres fitted are capable of carrying the vehicle’s weight.
A safety warning regarding the data sheets: Some of the American RV motorhome data sheets are out of date.
In the above image, the tyre pressures are quoted as single (front) 70 psi and dual (rear) 65 psi. This plate relates to a motorhome built in 1996.
When the motorhome came from the factory, it would have been supplied with Michelin tyres. The maximum tyre pressure for a Michelin tyre size 8R195 would have been 80 psi; however, this Michelin tyre changed around 2000 to a maximum of 90 psi.
As things progressed, owners began to fit 225 x 70 x 19.5 tyres to the exact rims of their vehicles. This now makes the vehicle’s data plate incorrect. To make things worse, the Michelin tyre, being perfect, became very expensive. Let’s face it, you don’t need to spend a fortune on a tyre to watch it degrade the same as a tyre half the price.
A replacement for a premium Michelin is a budget tyre, unless you are covering 20,000 miles or more per year. I would stick with a premium brand tyre. Budget tyres will provide a slightly more challenging ride, with most having a maximum tyre pressure of 110–120 psi. The tyre pressure on the tyre has no relation to the data plate anymore. If owners are not aware of this, they could be running their tyre pressures far too low for safety. This is why on the tyre inspection sheet, previous and present tyre pressures are noted along with the tyre tread depth of the middle and two outer edges. These measurements are carried out with the wheels removed from the motorhome to enable easier inspection of the tyres, and then, if necessary, the wheels are rotated from front to back or left to right.
Checking the Chassis components
The AMS service includes a chassis and lighting inspection that exceeds MOT standards. An MOT inspection carried out at an MOT station provides a snapshot of the vehicle’s condition on the day of the test. Corrosion inspection is valid for a month.
At AMS, we are inspecting the vehicle to ensure it is safe until the following year. For instance, if a lower ball joint has lift in it, we will know what the maximum the manufacturer allows, and armed with this information, we can decide whether to leave it or replace it.
If you combine your MOT with your service, you will not need to undergo another inspection. The reason will not present a vehicle for an MOT test without first inspecting it is that, morally, we could charge you for the retest. So, who are the RV motorhome experts: AMS or the MOT station?
On the service, the steering ball joints, brake pipes, kingpins and suspension components are checked and all greased. All items inspected during an MOT inspection are also inspected during a service, including emissions.