richard5933

Since most of us are concerned about storing our vehicles through the cold winter months, I'm wondering how the temperature affect the different migration processes being discussed. If my high school science class learning still holds, chemical reactions and physical transitions all happen in slow motion in freezing temps. We plan on parking our coach on gravel this winter. Not by choice - our driveway and parking area is gravel. My concern has always been more about the moisture (and varmints) migrating from the ground to the belly of the coach. That's why we won't be parking on the grass area, even though it would have been more convenient. I will cover the tires to avoid UV damage and make sure that the tires are fully inflated. During those few warm days each month that seem to sneak their way in, we will move the coach around our property a little to keep the fluids distributed and to avoid having the tires with the same side down all winter. Other than that, I won't be taking any special preservation steps I might be poking the hornets nest here, but it strikes me as odd how much worry the RV community has over tires. I've lived in Wisconsin for a few decades, and we have many businesses here that have idle vehicles at times (especially through the winter). Some of them are idle through an entire season. I've yet to see one that jacked up their vehicles or parked on Teflon sheets. In my thinking, our tires are going to need to be replaced based on age long before mileage or any other type of issue takes them down if we follow a few very simple precautions - key among them is proper inflation when we're on the road. If I get seven years from my tires I'll consider it a good deal. As my mother would have said about this, why waste a good worry?

What is your heat source? A lot of people have problems with condensation when they heat with unvented propane heaters. I've read that for every hour you run an unvented propane heater between a quart and gallon of water is released into the air. Propane heaters that vent the combustion gases outside are a better choice if you have a choice. Electric heat tends to make air dryer.

Update on this... Project is now complete other than reinstalling the furnace in the coach. I'll do that as soon as it warms up a bit or gets sunny enough to warm the inside of the coach. Ironic, eh? Fixed the furnace but now it's too cold to work outside. The motor came in and was an exact fit for the original. The only problem was that the new motor had three mounting tabs spot welded onto the motor case. The original mounted with a wrap-around clamp. A little time with the Dremel took care of that. The original rubber crossover tube was replaced with a high-temp silicone tube which is sold as an intake tube for guys that hot rod cars. It's four-ply reinforced and was sized nearly exactly to the original. It holds in snugly and I think is going to do the job just fine. Here are a few photos of the work: Cutting off the mounting tabs Motor back in the original mount Motor with blower Old (right) and new (left) crossover tube Crossover tube in place

Rich - I hadn't thought about just replacing the rubber crossover with something similar but better. I'm guessing that silicone tube like this didn't exist or wasn't widely available in the 70s -80s when the recall was going on. I found an appropriately-sized high-temp silicone tube on Amazon and it will be here tomorrow. Seems like it will fit, and if so it will greatly simplify putting things back together. I'm not recommending that anyone else try doing this, but I'll report back to let others know how things work. I will be coupling the repairs to the furnace with a brand new carbon monoxide monitor. Belt & suspenders.

Here are two photos. One shows the flange on the side of the burner housing. There is a corresponding flange on the blower housing which sits at the other end of of the tube. The rubber crossover tube is simply a press fit onto these two flanges and is held in place by being sandwiched between them. The second shows the crossover tube in place. The recall part consisted of replacing the rubber tube with a metal one. I've got a piece of exhaust pipe which is a very snug fit over the existing rubber crossover tube. I'm hoping that I can cut off two rings from the existing tube, each about 1/2" wide, and use them as a gasket between the new metal tube and the flange. That and a bit of high-temp silicon gasket sealant to ensure that there is no movement of the rubber gasket inside the tubes.

Started working on the furnace today. Here are a couple of photos of what I found. Basically, this is what a 43-year-old unused heat exchange unit and burner look like. The heat exchange unit looks brand new. The burner has some surface rust but no corrosion or any problems with the slots. It really looks like the furnace was only used once or twice. The condition of the furnace is why I was willing to attempt the blower motor swap. The motor should be here tomorrow and I expect it to go in easily. The only thing I have not figured out yet is what to do with the crossover tube that was the subject of the recall years ago. Apparently the rubber tube became dry, developed cracks, and then leaked CO. Mine is still soft and pliable but I really don't want to wait until there's a problem to fix it, especially when I've got it apart right now. The recall fix was to replace the rubber tube with a metal one, but the recall replacement part is apparently NLA. I've got a piece of 3" muffler pipe which I think will work to make a metal replacement for the rubber tube, but I have to figure out how to best gasket it on the ends. The rubber was just press fit onto the flanges at either end. The muffler pipe I have is a very snug fit over the existing rubber tube, so I'm contemplating cutting off about 1/2" wide rings from the rubber tube and using them as gaskets on either end of the metal tube. That combined with some 400-degree RTV silicon for good measure. Any thoughts or suggestions would be most welcome.

That was my plan, but after doing some research it seemed that oiling the bearings would be a short-term solution. When I found that the motor was still available I decided to just order one and try for a longer-term solution. Once I know that the new motor is in place and working, I'll probably try to open the original and see what could be done to repair it.

Pest control companies all discourage the use of mothballs for pest control. It's apparently an off-label use and not permitted by the EPA. No one is probably going to get dinged for this, but a heads up is in order. I just looked up mothballs, and apparently the older formulation (naphthalene) is quite flammable. The newer one (paradichlorobenzene) is less flammable but more toxic. My main approach is going to remain exclusion. Beyond that and the various traps and bait stations, it seems like frequent inspections for signs of activity is going to be the best bet so that steps can be taken before any serious damage is done.

I was actually able to get the furnace pulled without too much trouble or too many scraped knuckles. Luckily the floor of the wardrobe above the furnace was screwed in and acted as an access panel. The carpet in the wardrobe will need to be replaced, but otherwise things went well. The inside of the furnace is actually pretty clean - looks like it was only used a time or two. All the paint is still on the heat exchange unit and other than a very stiff motor I can't really find a problem. On 120v it fired up and ran okay once the blower got to speed. It ran on 12v, but the motor really pulled hard on the batteries so I only did that for a brief time. On a whim I called Suburban to see if they had a cross reference for a current motor which would fit our furnace. Believe it or not, they did. One is on order and will be here in a couple of days. Hopefully things will go together well and I'll be able to make this thing last at least another season or two. I'll try and post some photos as I do the motor replacement. The attached photo is of the empty cabinet where the furnace goes. Really glad I found the removable panel under the carpet.

Wow, all this talk about solenoids and remote switches makes me glad that our system is so simple. Rotate the switch next to the chassis batteries from on to off and the battery is disconnected. Same for the switch next to the house batteries. Even if our coach was born in this century, one of the first things I'd install would be a truly mechanical battery disconnect switch. I'd use it every time I parked for more than a day or two. A really nice Blue Sea switch can be ordered for less than $100 and will outlast my bus. I would avoid anything generic or made overseas unless it was a known high-quality item. The automated systems can be left in place - the manual switch is my mind is in place to act as a fail-safe to avoid any unknown phantom loads draining batteries.Best placed as close to the batteries as possible.

The bait is designed for any that get inside despite all efforts to keep them out. The theory is that when they eat the bait it causes extreme thirst. Since the bait is basically a blood thinner that seems like a likely result. If things work out the way they're planned, the mice will seek out water after consuming the bait. Not finding any inside, they will go back out the way they came in and have the decency to die outside. Unfortunately, it doesn't always work out that way. I've had more than a couple die inside - not very pleasant. However, I'll take a couple of stinky dead mice over a live one eating away at my wiring any day. Dead mice do little damage other than causing a stink. Live mice cost me a 12.5kw generator.

I've been using the Garmin 760 with pretty good success. The biggest issue for us has been when I don't have it plot the route and try to wing it on my own. Inevitably I'll end up with the thing screaming at me about a weight limit. Now I try to use the Garmin for everything unless I know the route to be safe. The Garmin does consider vehicle height, length, width, and weight. It won't create a route that would be a problem unless there are no other options, and then it warns you at the outset that there will be issues.

This is a big issue for us. On our first coach we lost a nice generator to mice when they ate the insulation on the wiring in the control box. We have a company that does pest control for us at home. Just had a talk with the guy when he was here this week. Biggest suggestion is to be sure to minimize access as much as possible. A mouse only needs a 1/4" wide opening to squeeze through. My plan is to check every corner of all the basement bays and fill every crack or space with caulking. For areas that I don't want a permanent seal I'll use what our pest guy does - a very coarse steel wool. That should work in places like the space around the generator exhaust pipe where it exits the bay. Any places that might get damp or wet I'm planning to use stainless steel wool (like they make pot scrubbers out of). Check around anywhere that wires, cables, plumbing, or other bits and pieces enter the coach and pierce the outer shell. It's surprising how many places like this there are in a coach. I'm going to make a list of any places I close up that will need to be re-opened in spring - with my memory I wouldn't be surprised if I forgot half of them otherwise. I'm also going to place bait stations throughout the inside of the coach as well as in the bays. If any mice make their way inside, I want their days to be limited. I'm also planning to strategically place a few sticky traps in places where it's not possible to make a totally tight seal. On our coach the bottom of the entry door doesn't seal 100%, so I will place a sticky just inside the door. Of course I'll have to remember it's there so I don't stick to it myself. Of course, removing anything that a mouse could possibly interpret to be food is important - this includes any cardboard or paper products that they might see as useful in building a nest. One last thing that I learned years ago trying to keep mice out of our house is to be sure that the area around whatever you're trying to protect is clear of tall grass, piles of leaves, or other hiding places. This just makes it easier for rodents to stake out the building or vehicle they are trying to enter and gives them cover as they come and go. These are my plans. I'd also love to hear from others what they've found works for them. Good luck.

Definitely a 70's era unit. I believe that everything in our coach is as it was when it left Custom Coach in 1974. Only 40k miles on the coach, and only 900 hours on the generator. The generator has the two 30-amp breakers and feeds the main panel through a manual transfer switch. I actually prefer the manual switch. After reading the comments, I am pretty set on just going with the Echo Charger for the 8D battery. At least until I have reason to abandon that method. I can always replace it with a constant duty solenoid if I find that the 15 amps is not enough. I do like the fact that the Echo Charger will not allow the house batteries to ever pull from the 8D so I shouldn't have issues with a dead battery due to something in the house system draining it. Thanks for all the suggestions.

A little more information: 1. The 24v coach system is totally separate and not what we're talking about here. There are no connections between the coach 24v system and the house 12v system. The generator has its own 12-volt 8D starting battery. 2. All the batteries under discussion are flooded cell. 3. The setup as I got it was what was done in the original conversion in 1974 by Custom Coach. They used the 8D as both the generator start battery AND the house battery. Not a great setup since the battery is not a deep cycle and of only limited usefulness when not running the generator. This is why I'm installing a new house battery bank made of four Trojan 6-volt L16 batteries. They will be set up to run as a 12v house battery bank by being connected series/parallel. 4. The new 120v charger is being connected to the house bank to provide charge whenever we're on shore power or generator. It puts out 70 amps. This is the level of charge recommended by Trojan (approx 10% of battery bank capacity). 5. The generator is a 70s-era Kohler 12.5kw powered by a Perkins diesel. Generator model is 12.5RCOP67. Only 900 hours on the generator, and other than a few minor oil leaks which I'm fixing it runs ok. There is a battery charging circuit in the Kohler, but according to the manual it is an on/off system and will keep charging even when the battery doesn't need a charge. Sounds like a setup to boil a battery, and I won't be using this. Hence the need to come up with some way to charge the generator start battery. There are two options I see as most viable. The first is to install a solenoid to bridge the 8D generator start battery to the house bank whenever the generator is running. This would charge the 8D along with the house batteries from the 120v charger. My concern here is that the house batteries are deep cycle and the 8D is not, and also that the house batteries and the 8D have different capacities. I didn't know if I'd end up with a situation where one set would be overcharged and one would be undercharged. Or, if this would create a situation in which my house batteries did not ever fully charge. The second option is to use something like the Xantrex Echo Charger. It would siphon up to 15 amps off the house batteries whenever they are being charged and send it to the generator start battery. My concern here is if 15 amps would be enough to keep the need of the generator for 12v while running and still be able to top off the battery. The generator needs a few amps to run it's electric fuel pump and a few to keep the fuel solenoid open. This is probably my preferred option. Thanks again for any advice on making this decision.

I have been using one of these for the tires on our coach: PORTER-CABLE CMB15 150 PSI 1.5 Gallon Oil-Free Fully Shrouded Compressor With the higher 150 psi cut off it seems to have no problem adding a few pounds of air to top off the tires. I don't think it would be much good to fill a tire if it was 'really low', but then again if one of my tires is 'really low' I'm going to have the spare put on before going anywhere anyhow. Got it on Amazon for around $100. I also have an outlet on the on-board air system I could have used, but I found it much easier to maneuver an extension cord than an air hose. It was really getting to be a PITA to drag out 50 feet of air hose and try and maneuver it to all four corners. This compressor is light enough that I can easily move it about, and the extension cord is something that we use often so it's always at hand. Of course, this method requires that the coach is either on generator or plugged into shore power.

I've got a 12v house battery bank made of four Trojan L16 batteries. They are being charged by a Progressive Dynamics 9270 charger which puts out 70 amps. The generator has its own start battery, which is currently an 12-volt 8D Deka start battery. (I know, it's overkill for the generator, but it came with and is nearly new). The question is this... The charging circuit in the generator is very old-school and will probably boil the battery if used for too long. There is no alternator on the gennie, and no place to easily install one. Would it be acceptable as an alternative to use an automatic solenoid to bridge the 8D starting battery to the house battery bank? The thought is that whenever the generator is running it will be connected parallel to the house battery bank and receive a charge from the Progressive Dynamics 9270. After the generator was shut down, the solenoid would disconnect the starting battery from the battery bank, and there would be no chance of waking up in the morning with a generator start battery too weak to restart the generator. My only real concern is adding a battery of a different type and size to the house battery bank while charging. I didn't want to create a situation where either the house or start batteries would over/under charge. My gut feeling tells me that this is just going to end up being similar to bridging house and chassis batteries together for the purpose of charging off the engine alternator while driving. Interested in seeing other's thoughts on this. Thanks for your help.

Trying to get our 1974 GMC Coach up and running. Got the LP system tested for leaks and safety issues, then tried to fire up our Suburban furnace. Things overall went okay, but it seems like the motor/blower is in need of help. The blower starts really slow, squeaks a bit, then eventually starts to blow air. On 120v it's okay once it gets going, but on 12v has trouble getting up to speed. Anyone have experience either rehabbing the motor or replacing them? I assume that I'll have to pull the furnace to get to the blower & motor, but first I want to know if it's worth trying. Thanks.

There's a Motor Home Hall of Fame? Is that the same as the museum in Elkhart of something else?

This is actually our second coach. We had a 1964 GM 4106 until recently. It was converted in 1990 (we think) by Custom Coach. This new coach is a 1974 GM 4108a, and it was converted in 1974 by Custom Coach. With only 40k miles, the whole thing is like a time capsule. Condition is great, but since the conversion was done 43 years ago we'll end up replacing most of the electric/electronic components to bring it up to modern standards. I'll post a few interior photos soon.

Our previous coach, a GM 4106 averaged about 7 mpg. Mostly kept to 62 mph. That coach had Detroit Diesel 8V71 with Allison 730 automatic. Our current coach, a 1974 GMC 4108a averages about 8.5. Same speed, but the 8V71 on this one is mated to a 4-speed manual transmission.

He she is! Drove it home to Wisconsin from NJ this past week. Only 40K original miles. Interior is like 1974 all over.

Long time reader - first time posting... We just brought home our 'new' 1974 GMC 4108a conversion, and when going through the drawers we found something interesting enough that I thought it worth posting here. A little piece of FMCA history. Hope it brings back good memories. Richard