wolfe10

There are three different "auxiliary" braking systems used on different diesel engines.: Exhaust Brakes, Engine Compression Brakes and Variable Geometry Turbo Brakes. Exhaust brake: literally a "flap" which closes off exhaust flow just downstream of the turbo in the exhaust system. This causes back pressure (55 PSI on ours) which generates braking power. With the Allison transmission, the exhaust brake is usually tied with downshifting of the transmission to the "pre-selected" gear (usually 2nd or 4th). Think of it as a potato stuffed in the tailpipe. Engine Compression Brake (aka Jake brake): The exhaust valves are opened as the pistons reach TDC (Top Dead Center) on the compression stroke after the engine has done the "work" of compressing about 18 volumes of intake air to 1 volume. If the exhaust were not let to escape by the compression brake's opening, the exhaust valves (i.e. coasting with brake off), the "compressed air" would mostly be returned as power to the engine, forcing the piston back down. With the Jake brake on, the engine works to compress air in the cylinder, and then the air is let out. This generates quite a lot more braking force than an exhaust brake. The smallest engines to offer an engine compression brake are the Caterpillar C9 and Cummins ISL. Variable Geometry Turbo: The vanes reverse or aperture closes (depends on engine manufacturer) to create back pressure with much the same effect as an exhaust brake. Brett Wolfe

Calibrating the engine oil dipstick We continue to see concerns about oil "consumption" and oil on radiators and toads on many RV Web sites. It seems to be universal across all brands of diesel engines. THE NUMBER ONE CAUSE IS AN OVERFILLED CRANKCASE. CALIBRATING THE ENGINE OIL DIPSTICK TO ACHIEVE THE CORRECT OIL LEVEL IN THE PAN "FIXES" OVER 90% OF THESE PROBLEMS. Step one if you "think" your DP has an oil consumption problem or you are seeing oil mist on your toad (or you just want to verify that yours is correct): CALIBRATE THE DIPSTICK. Since the same engines/dip sticks are used in many different applications with different angles of installation, do not ASSUME that the dip stick is correctly marked. This applies to all age (including brand new) motorhomes and boats with every brand of engine. Calibration costs $0. At the next oil change, drain oil, remove old filter (as usual). Then install the drain plug and new oil filter and add the engine's correct oil capacity LESS THE NUMBER OF QUARTS you want between the "add" and "full" marks (let's say 2 quarts). So, for example, for a Caterpillar C7 with 19 quart capacity you would add 17 quarts. Run the engine a few minutes, shut off and wait until oil has descended into the pan (at least 30 minutes and an hour is safer). Pull the dip stick and use a file or dremel tool to mark the oil level "add." Add the remaining two quarts, let the oil settle in the pan, pull the dipstick and mark this the "full" mark. In many/most cases, you will find that your engine "throws out" the access oil and then "consumption" settles down to next to nothing. Put in the correct amount and your "consumption" issues may go away. Also, when checking the oil level with the dipstick it is safest to do it in the morning after the oil has had all night to flow back to the pan. Brett Wolfe

Coach Ride Height Safety Caution: Never go under a coach without adequate safety stands. Importance of correct ride height: If ride height is too low, the suspension can bottom out on bumps, giving a harsh ride and shocks can be crushed on compression. If ride height is set too high shocks can pull apart on extension and the center of mass is raised. And either too high or too low can destroy the U joints and drive shaft, particularly on a Diesel Pusher. Even 1 inch out of spec on a DP driveshaft significantly alters driveline angles. It will also transfer a huge amount of weight from side to side. How many of your really strong friends would it take to lift the left rear corner of your coach! Ride height is critical to ride, handling and to component longevity. All chassis makers have specifications for the correct ride height, leaf spring, Torsilastic and air suspensions. A proper wheel alignment can not be done before correcting ride height. Ride height specs are generally from a given point on the axle to a given point on the chassis rail. Leaf Spring Suspension: Out-of-spec ride height on a leaf spring suspension can be caused by worn springs, shackles or out of spec weight on a corner. It can be corrected by replacing the springs, adding a spacer shim, adding a leaf or moving weight. Truck suspension shops make these repairs routinely. Torsilastic Suspension: On Torsilastic suspensions found on some Foretravel and some Safari products, ride height is raised by removing spacer shims. Each shim is ¼†thick and removing one from in front of and behind a wheel position raises that wheel position ¼â€. Loosen, but do NOT remove the long bolts securing the shims. The shims are slotted and are easily removed. Torque nuts on the long thru-shim bolts to 115 ft-lbs. Air suspension: Most coaches with air suspensions use 3 ride height valves: two on one axle and one on the other. These valves can leak and/or the light-duty rods used to attach them to the axle can be easily bent by road debris. Check and adjust ride height at least twice a year or anytime you run over road debris, notice a change in ride height, a change in ride quality, the coach is too low for the jacks to deploy properly, steps are closer to the ground, etc. According to Walter Cannon of RVSEF (Recreation Vehicle Safety Education Foundation) (http://www.rvsafety.org/), who performs all wheel position RV weighings around the country, incorrect ride height has led to some of the most severe wheel position overloading they have recorded. For the schedule and location of coach weighings in your area, go to RVSEF Schedule. Brett Wolfe

When an RV (absorption-type) refrigerator will not function on propane: 1. Verify that you do have 12+ VDC to the back of the refrigerator-- the PC board requires 12 VDC to operate on propane as well as on 120 VAC. 2. Turn on propane stove and verify normal, steady flame. 3. Do annual burner-area tune-up as described in your refrigerator's owners manual. It takes no parts and no special tools. Issues addressed are: cleaning propane jet, cleaning burner tube, cleaning and setting igniter gap, etc. 4. If still does not work, remove, clean (preferably with DeOxit--DeOxit) all electrical connections on the PC board and ground lug. Only after doing this should you suspect expensive parts such as PC board, gas valve, igniter, cooling unit, etc. Brett Wolfe

According to the 2002 FMCA Towing Guide (FMCA Towing Guide), the Taurus is not listed as towable 4 down without modification. A quick search of Remco's website (Remco Towing Guide) says this model is only towable on a dolly (they do not make drive shaft disconnects for it). Brett Wolfe

Ron, You don't say what size batteries you have. If group 24 or 27 that is on the high side unless you are in really hot conditions. If 8D's or other larger batteries, you are in the "normal" range. But, do yourself and your batteries a big favor and VERIFY voltage. If you have a smart converter, smart charger or smart inverter/charger, do this at least 24 hours after plugging into shore power to insure that it has gone into FLOAT MODE. Use a digital voltmeter (available at Radio Shack, Sears, etc starting under $25). In the summer, 13.0-13.2 VDC is ideal with 13.5 VDC being at the high end of acceptable. If you have a smart inverter/charger, be sure it is properly programmed for high temperatures. The charger's owners manual will cover this. Brett Wolfe

As Tom said, your solar panel output may not be enough to overcome "parasitic" loads. From your description, you are not storing the unit plugged into Shore power. Indeed, as kalynzoo said, once batteries are completely charged, have the batteries load tested-- if original they are likely at the end of their normal life. Batteries can NOT be tested until they are fully charged. If batteries test good, there are three options: 1. Store plugged into shore power and let your converter or charger maintain the battery charge. 2. Lessen the electrical draw by removing 12 VDC fuses from parasitic loads that you do not need. Brett Wolfe

Proper battery charging is important to battery life irrespective of what type of battery you have (wet-cell, AGM, gel). Proper FLOAT VOLTAGE (voltage AFTER batteries fully charged-- like more than 24 hours after plugging in) should be 13.0-13.5 VDC. In the summer, 13.0-13.2 VDC is ideal. Higher voltage WILL overcharge batteries, cause them to use water, etc. As suggested, not all devices used to charge batteries are equal. There are basically two levels of "quality" of chargers: "Stupid" converters-- those that charge at the same voltage whether the batteries are fully discharged or fully charged. "Smart" converters, "Smart" chargers or "Smart" inverter/chargers. Substantially better because they charge discharged batteries at a higher voltage (BULK MODE), then taper off in ABSORPTION MODE and after fully charging, maintain the batteries in FLOAT MODE. Please pull out the owners manual for your converter, charger or inverter/charger. If a "Smart" one, read the section on programming it. Make sure it is set on SUMMER/high temperatures. Unless it has a temperature probe found on real high-end units, YOU have to tell the charger whether the batteries are at freezing or 100 degrees F. And if set for winter temperatures, it will be overcharging the batteries when it is hot outside. If you have a "Stupid" converter or after programming your "Smart" charger, use a digital voltmeter (available at Radio Shack, Sears, etc starting under $25) to check voltage at the battery at least 24 hours after plugging it in (to insure you are measuring FLOAT voltage). Again 13.0 to 13.2 VDC is ideal in hot weather. Brett Wolfe

Actually, carrying spare belts is a great idea whether you can replace them or not. You will find those who can replace them virtually anywhere you travel, BUT finding the right belt in the middle of nowhere is a different matter. And if the present belts are over 3 years old, replace them and save the OLD ONES as spares. That does two things: 1. ABSOLUTELY assures you that you have the correct belt. 2. Lessens the likelihood of a belt breaking. Brett Wolfe

Frank has pointed out the basic flaw in this-- most CG 15/20 amp outlets are GFI protected (per current code). This device will NOT work with a GFI. And even if it is not GFI protected and the device works, remember, you are not getting the same amp service as 50 amp. With 50 amp, you have TWO 50 AMP HOTS= 100 amps available. With this device you have one 30 and one 15 or 20 amp hots= 45 to 50 amps available. Brett Wolfe

For CG boxes providing 50 amp service (perhaps along with 30 and 15/20 amp service), there are 4 wires from the CG main breaker box: 2 hots, a neutral and a ground. If you have 50 amp service to your coach, you are gaining nothing by taking part of the load on a separate 15/20 amp circuit. The 50 amp service provides 50 amps on EACH of the two hot legs. So you can use up to a total of 100 amps. It is very doubtful that you will use anywhere near 50 amps PER hot leg. If you have 30 amp service to your coach, you are limited to 30 amps ( a LOT less than 100 supplied with 50 amp RV service). So here, your extra 15/20 cord will allow you to run more "stuff" from the 30. Brett Wolfe

Let me add to Jim's post. If you do park with three wheel positions at about the same level and one wheel position 6" lower (your high-crowned street for instance with curb-side wheel up on the driveway) please use leveling boards under the low wheel position OR use your leveling jacks. You will put quite a bending torque on a chassis leaving it parked with three at one level and one at another. Brett Wolfe

I will repeat one more time-- a 5000 pound hitch does not necessarily mean that your coach was designed to tow 5000 pounds. THE authority on towing capacity is your coach manufacturer. Towing capacity is determined by the LEAST strong component. Much better to confirm before you spend your money than to find out you are operating dangerously/illegally. Brett Wolfe

There are several thing that you need to determine: Coach GCWR (Gross Combined Weight Rating) Towing capacity-- remember the LEAST strong element determines capacity, NOT hitch rating. It could be brakes, transmission, coach frame or indeed the hitch itself. Rear axle capacity-- the tongue weight will add well more than its actual weight to the rear axle because it is located so far behind the rear axle. Indeed, as Jim said, an equalizing hitch will help redistribute tongue weight. You need to weight your coach and verify that with the loaded coach, car and trailer you are considering that you will be under GCWR. And with a 33' gas chassis coach pulling a 24' trailer, handling WILL be affected. Brett Wolfe

Your coach house AND chassis electrical systems are 12 VDC, not 6,24,48, etc-- same 99% of all coaches out there . You can achieve that 12 VDC by wiring any number of 12 VDC batteries in PARALLEL, or by wiring PAIRS of 6 VDC wired in SERIES in PARALLEL. To make it easier to visualize, consider a "pair of 6 VDC batteries wired in seires" to be a "12 VDC battery"-- that is what they are. Tom is correct, you want DEEP CYCLE batteries. There ARE 12 VDC deep cycle batteries, but they are rare compared with 6 VDC/golf cart batteries. Go to the battery manufacturer's website and CONFIRM that the 12 VDC batteries you got are indeed deep cycle and not starting or marine batteries. And you could have done a LOT of damage to your 12 VDC system running it on 24 volts, which is what you would have if the wires were attached on the 12 VDC batteries as they were on your old 6 VDC batteries-- light bulbs, PC boards in refrigerator, furnaces, water heater, etc. This is something that anyone working on batteries/RV's (including all RV owners) should KNOW. TURN EVERYTHING OFF/DISCONNECT THE BATTERIES/TURN OFF CHARGER IMMEDIATELY. After re-wiring to 12 VDC, have a qualified RV tech check out ALL 12 VDC items-- I mean ALL. Brett Wolfe

Tom, An OPEN neutral is easy to diagnose-- voltage will be way off from 120 VAC plus/minus 10 VAC. What he found was not an open neutral, but a neutral connection with a lot of resistance (enough resistance to cause enough heat to melt insulation and discolor wires). There was enough conductivity to handle small amp loads, but not high-amp loads. I can no think of a way to detect this either except to have a digital voltmeter/polarity checker plugged in all the time (and monitored when larger loads applied). Both AEC and Good Governor made/make these. I have used one for the last decade on our coach. Have not yet run into a "partial neutral", but, a fair number of mis-wired outlets. This is particularly true in Mexico, where until recently no ground was required, so reverse polarity a frequent issue (frequent enough that I a made a reversible adapter to quickly and inexpensively "reverse it"). With one of these monitors (they plug into any standard house-type outlet in your coach) one can be careful without having to go overboard to paranoid. It becomes second nature to check the meter when adding heavy loads. Brett Wolfe

Tom, Indeed the most damage we have ever seen to coachs' 120 VAC systems was from an open neutral in a high-end CG in Vermont. AN EXCELLENT REASON FOR CHECKING VOLTAGE AND POLARITY BEFORE PLUGGING IN. As always, I checked the CG outlet before plugging in with my Fluke meter and read voltage varying from 145-177 VAC!. Sent Dianne up to the office for repair or other site. Checked voltage at second assigned site and read the same. Finally, (Dianne and CG owner not happy campers at this point) another site on the other side of the park where voltage was fine (118 VAC). Ya, you guessed it, "no one else has complained-- must be my problem". After setting up camp, went over to the "high voltage" area and asked several campers if they were experiencing high voltage. You guessed it, no one else had checked voltage, but ALL were running on 160+ VAC when I checked their sites. Several thousand dollars worth of A/C's, TV's and microwaves damaged. After two days of digging with a backhoe, the electric contractor found a break in the neutral wire under a culvert. Moral of the story-- always check voltage and polarity before plugging in (and check voltage again as you add high-amp loads). Brett Wolfe

Cathe, Indeed, you are shortening the life of your refrigerator. Can you not drive the right wheels up on leveling boards on the curb side to compensate for the crown? THAT is the right answer. Brett Wolfe

Richard. Welcome to the FMCA Forum. I would be VERY surprised in your coach is was not wired from the factory with the alternator charging BOTH battery banks. Is this "no charge" of house battery bank a recent development or has it always done that? Have you checked voltage with a digital voltmeter? With engines off and shore power off, check voltage at house and again at chassis batteries. Start engine and check again at both battery banks. WHAT ARE THE READINGS? And indeed, if you find that not only does yours not charge now, but that it was not designed to charge both banks, there are solution that are reasonably simple. Easiest (KISS): Buy a marine simple ON-OFF 360 amp continuous duty switch. Install alternator output and chassis battery to one side and house battery to the other side. Now, with switch off, you are charging only the chassis battery. With switch on, you charge both banks. This will also work to charge both banks from the charger/converter and service as an emergency start "combine" switch. Only issue is that you need to turn the switch OFF when dry camping so that you do not run down the chassis battery. You can also use a HD CONSTANT DUTY solenoid to combine the banks. Size (in amps) must be equal to total alternator output. Connect chassis battery to one large lug. House battery to the other large lug. Small signal wire to ignition source (if you want them both charged every time you run the engine) or to a 12 VDC switch that you can turn on as you want. Brett Wolfe

Linda, Belts break for a number of reasons: All rubber parts become more brittle with age. There could be a slight mis-alignment of the pulleys. The belt could have been over/under tensioned (always check automatic tensioner when replacing the belt. Stones or other debris could have been kicked up between the belt and a pulley, damaging the belt. One of the accessories can be seized up (usually alternator or A/C compressor). Always spin all pulleys when changing a belt. The belt could have been installed incorrectly-- with the grooves one tooth off (in or out) on a pulley. Brett Wolfe

Freightliner should be able to e-mail you or fax you a diagram. They are the ones who route the serpentine belt (as they spec the alternator and A/C compressor). While changing the serpentine belt, suggest you also replace the Caterpillar speced (get from Caterpillar dealer) water pump belt. If the old belts are still in place, you can always draw serpentine belt routing before removing the old belts. Brett Wolfe

Good post. There are many reasons we need to pay more attention to the quality of 120 VAC service in CG's than in stick homes. Many CG's electrical systems were designed decades ago when the largest electrical draw in an RV was maybe a TV and a fan. Certainly not a two A/C with microwave and 120 amp charger running at the same time. Much of the wiring/pedestals are out in the open and exposed to moisture, dirt and abuse. Many CG's are located outside municipalities with ENFORCED electrical codes. Many CG electrical outlets have been corroded, pitted and sprung by thousands of users/abusers. Many CG's electrical systems have been "fixed" by owners or RV'ers. Either buy an "automatic" 120 VAC system monitor/management system or (as I do) pay attention! I check polarity and voltage before I plug in and recheck voltage (large-display plug-in voltmeter) each time an additional high-amp load is added. Also, unplug anytime there is an electrical storm in the area. Contrary to ads, NO surge protector will protect from a direct/near-direct lightening strike. By properly monitoring the 120 VAC power, we have never had a problem with our rig caused by poor 120 VAC power, and that includes 5 winters spend in Mexico where power is even more questionable than north of the border. Brett Wolfe

CORRECT TIRE PRESSURE To determine the correct tire pressure for your coach, neither Michelin nor Goodyear recommend carrying the PSI imprinted on the tire sidewall UNLESS YOU ARE CARRYING THE MAXIMUM WEIGHT which is also imprinted in the sidewall. Go to Michelin or Goodyear's RV Tire Guide and you will see that the tire manufacturers do NOT have a single recommended tire pressure for each size tire, but always show a chart where correct PSI is based on actual weight. So how do you do this correctly: BEST way is to load the coach as you go down the road. Get all 4 (or 6) wheel positions weighted. RVSEF does this at all FMCA events and many other places. Of course you can just weight axles, but here you are ASSUMING perfect left to right weight distribution-- something that is NOT true on the majority of coaches. Taking the heavier wheel position on each axle, go to the tire manufacturer's weight/PSI chart for your tire and determine the correct MINIMUM pressure. All tires on an axle get the same pressure based on the heavier wheel position. Many add 5-10 PSI to that as a safety cushion (so you do not have to go and recheck when your wife stops at the outlet mall). Next best-- look at your GVWR plaque which by law will be in the driver's area. On it will be recommended PSI BASED ON MAXIMUM GAWR. Here you are assuming your weights are not higher or lower than maximum. You had better hope that this number is wrong, or you have no safety margin in tire carrying capacity. Further down still-- put in what is on the sidewall of the tire. ASSUMES you have NO LOAD INFORMATION ON WHAT THE TIRE WILL BE CARRYING. Could be right on (hopefully not) or could be off by 20 or more PSI. All tire manufacturers recommended tire pressure are based on COLD (have not been driven) AT THE AMBIENT TEMPERATURES YOU WILL BE EXPERIENCING ANYONE WHO TELLS YOU WHAT PSI TO CARRY WITHOUT WEIGHTING YOUR COACH DOES NOT KNOW WHAT THEY ARE DOING. Example, the "correct" minimum tire pressure from the Michelin book for a 275/80R22.5 is 75 pounds if the load is 4,500 pounds and 115 if the load is 6,175 pounds. BIG DIFFERENCE. Brett Wolfe

Welcome to the FMCA Forum. 1. Google "Honey Motorhome"-- lots of information there. 2. Information you seek can roughly be broken down into three sup-groups: Chassis, house and RV systems. What chassis to you have? The house (like construction, sidewalls, roof) will be unique to your coach manufacturer. The RV systems such as water heater, furnace, A/C, refrigerator will be standard brand RV components. You can get detailed information on them from each component manufacturer. Brett Wolfe

Is the thermal cut-off FIRMLY against the tank? Brett Wolfe