Technical Inquiries: January 2005

Beetle Mania

Q: I want to tow a new Volkswagen Beetle with a manual transmission four wheels down. Are there any speed restrictions? What fuses or wires can be disconnected to stop the odometer and headlights?

Ted Smook, F330084
Ruther Glen, Virginia

A: When we have compiled our annual towing surveys in recent years, Volkswagen has indicated that it does not recommend towing any of its vehicles. The company hasn’t given any indication as to why it has taken this stance. I know years back the old Beetle didn’t track well, and those who chose to tow it had to put a bungee cord around the steering wheel and attach it to the underside of the seat to prevent wandering problems. You might check with Remco (800-228-2481) or some of the tow bar manufacturers to see whether they know of anyone who is successfully towing a new Beetle with a manual transmission. The bottom line, though, is that Volkswagen does not endorse the practice of recreational towing.

Q: Thank you for addressing the auto-park brake problem with such a great write-up (“Auto-Park Brake Questions,” August 2004, page 24). I read the article with great interest since I am a past owner of a motorhome built on a P-Series chassis with the auto-park brake. I owned the motorhome for seven years without a problem with the brake. However, the motorhome did experience other problems. One was a front brake caliper lockup, which required the motorhome to be towed for service.

That brings me to the point of this letter. In the auto-park brake write-up, it was not mentioned what should be done if the motorhome needs to be towed. In our case, the tow truck operator hooked the motorhome up to the tow truck, picked up the front end, and moved the RV one to two feet forward so he could disconnect the driveshaft. When he loosened the last bolt, the driveshaft sprang out of the yoke (breaking it) and hit him in the chest hard. He may have suffered a cracked rib, but continued with the tow. I was told by another motorhomer that the same thing occurred to him.

For safety reasons, if you own a motorhome equipped with an auto-park brake and it needs to be towed, you should perform the following procedures. After the tow truck is hooked up, but before the motorhome is moved, turn the ignition on and move the shift lever out of “park” to disengage the auto-park brake. After the driveshaft has been removed, shift the motorhome back to “park” and turn off the ignition. This is very important information for anyone who owns a motorhome with the auto-park brake.

Doug & Judy Johnson, F287232
Seaford, Virginia

A: Thanks for the information.

Q: I have a 39-foot motorhome. I plan to use a dolly to tow my Pontiac Grand Am. What is the law as to brakes on the tow dolly? Second, if I tow the Grand Am four wheels down without the dolly, what is the law as to supplemental brakes?

Herbert F. Thompson, F342747
Chesterfield, Virginia

A: Unfortunately, we don’t have a simple answer for you. Up until this year, the Motorhome Regulations chart published in the January directory issue of Family Motor Coaching magazine listed weights at which the various states and provinces require supplemental braking. However, these regulations generally were written for “passenger car trailers,” and there is debate as to whether the laws apply to motorhomes. Even when asking the question of state agencies directly, it was difficult to obtain answers, because opinions varied. Because of this uncertainty, and comments from members about this, the weights were removed from the chart for 2004. We do know that British Columbia, Canada, has a law that pertains to motorhomes and is actively enforced. Their law requires that towed vehicles that weigh more than 2,000 kilograms (4,409 pounds), or vehicles weighing 40 percent or more of the motorhome’s gross vehicle weight rating (GVWR) be equipped with supplemental braking and a breakaway system. Information about weights related to passenger car trailers does appear in the Digest of Motor Laws that is available from AAA.

State and provincial laws aside, we remind motorhome owners that the laws of physics always apply and safety is an issue. In addition, as towing has become more popular in recent years, chassis and motorhome manufacturers have clarified their positions regarding supplemental braking. Here is what the Ford literature says about towing and braking: [The] “towing vehicle’s braking system is rated for operation at GVWR “” NOT GCWR. Separate functional brake systems should be used for safe control of towed vehicles weighing more than 1,500 pounds when loaded.” Other companies specify even lower weights at which point braking is required. The RV industry borrowed some of its weight terms from the trucking industry, and in that industry it is assumed that the trailers being towed have independent braking systems.

The July 2003 issue of Family Motor Coaching included an article that described the supplemental braking systems on the market today. In addition, we have published articles in the past about RV weights and tire safety (most recently in September 2003).

Both of these articles are available on FMCA.com/magazine (member log-in required). However, if you are interested in obtaining a photocopy of either of these articles, please feel free to send a self-addressed, stamped, business-size envelope to FMC, attention Editorial Assistant.

Q: We have a 2004 Winnebago Adventurer on a Workhorse chassis that is powered by an 8.1-liter Vortec engine with 8,000 miles on it. On a recent trip, our engine started missing. We took it to a Workhorse repair shop. The service writer said that the problem was likely caused by the number 5 spark plug wire becoming overheated and damaged. He also said this was common. The repair center replaced the wires and it’s been running okay so far. My question: Is this an ongoing problem? Will I have to replace the spark plug wires every 8,000 miles? Or is there a recall?

Raymond T. Myers, F267878
Belvidere, Illinois

A: According to a representative from Workhorse Custom Chassis, there have been some issues with spark plug wires becoming damaged by extreme heat in the engine compartment. The following information from the Workhorse representative summarizes the issue.

“In regards to overheated wires, we have checked with General Motors and they report that they do not have an issue on truck models using the same engine. This supports our conclusion that the heat is related to airflow in the engine compartment. We are working with the various body builders to better define airflow in the engine compartment.

“In regards to replacing damaged wires, the terminal snaps very securely to the spark plug. The wire must be removed by working it side to side to prevent the terminal from being pulled off the wire inside the boot. A damaged wire will arc internally, giving an impression that it was heat damaged. Most aftermarket wires without the metal heat shields will not provide adequate wire life.”

Q: While we were stuck in heavy traffic in our 1997 Coachmen Mirada, built on a Ford chassis, the steering wheel began to shake back and forth violently when the brakes were applied. Then the brakes failed completely. We were towed to a Ford dealership, but they could find nothing wrong and no service was performed. It has happened twice since: once in 90-degree weather and again with the temperature at 80 degrees. Mechanics can’t find anything wrong with the brakes. Do you have any suggestions?

Harry Green, F306091
Houma, Louisiana

A: Most likely, your problem is being caused by the brake fluid being contaminated with water. To explain how this happens and why it can cause brake failure, you must first understand a little bit about brake fluid.

Brake fluid is hygroscopic, meaning it attracts and retains moisture. It is designed to disperse any moisture that enters the brake system and hold the water in suspension. This is done so that the water, which is heavier than the fluid, doesn’t pool in the low points of the braking system, such as the wheel cylinders and disc brake calipers, where it can cause corrosion and oxidation to the various braking components.

This type of fluid solves one problem, but also can lead to another. During normal operating conditions the brake fluid temperature can rise well above the boiling point of water, 212 degrees Fahrenheit. Rarely would there be a circumstance during normal operation when the brakes were to develop enough heat to elevate pure brake fluid to the boiling point. However, the presence of water in the brake fluid drops the boiling point of the fluid. As the percentage of water in the fluid increases, the boiling temperature decreases.

When brake fluid boils and creates steam, it causes the system’s internal pressure to increase. This can cause the brakes to become activated, even though the driver never touches the brake pedal. Water vapor in the brake lines also can cause the brake fluid to be displaced from the lines and back into the master cylinder.

Unlike brake fluid and other liquids, water vapor can be compressed. With less fluid and more water vapor in the system, it’s quite possible that you could push the brake pedal to floor and still not activate the brakes.

Diagnosing this condition is tricky, because by the time your vehicle is examined, the brake fluid “” and water “” have cooled, and the cause of the problem has disappeared. It’s entirely possible that the service technician who checks the brakes may find nothing wrong, because, mechanically, there isn’t.

I recommend that you take your motorhome to a service center and have the fluid tested for water contamination. A reliable company that works on brakes should have test strips or equipment to determine whether the fluid is bad. If the fluid is contaminated, have the service center flush the brake system and add new brake fluid.

While researching this question I called Ford’s Motorhome Customer Assistance Center (800-444-3311). A representative there, reading from the latest Ford motorhome chassis guide, said that the brake system should be flushed and replaced with fresh DOT-3 brake fluid every 24 months. Other research indicated that brake fluid can and should be tested at least annually. Motorhome owners who tow another vehicle or trailer or those who live in areas with high humidity should have the fluid checked more often and replaced as necessary.
“” R.H.

Q: Having been a member of FMCA for several years, I have not read about a problem like ours. Last year my wife developed some problems walking. She now has to use a walker. She has been unable to climb the stairs in our motorhome. Do you have any information about a chair lift or some other device that we could have installed to overcome our problem? I am sure some of your readers have faced this before. We have a Silver Eagle bus conversion. We had it professionally converted in 1995 and haven’t been able to use it for more than a year due to her health problems.

Bill Bruce, F124643
Brownsburg, Indiana

A: We have featured such devices in the “RV Products” column in the magazine several times over the years. Following is contact information for companies that offer such products. One of these may have the lift product you are in need of: Bruno Independent Living Aids, (800) 882-8183, www.bruno.com; SFH Products, (888) 224-1425, www.lectraaid.com; Startracks Custom Lifts, (219) 464-1126, www.startrackslifts.com.