75 Overlander Improvements Journal

[Atomic_13]

Looking forward to following along during your refurb! Really nice trailer.

[4RXLA]

That's too bad that water got in the rear and rusted it out. I've been lucky that mine has stayed dry.

[TouringDan]

Originally Posted by dbj216

The steel angle iron, the steel U channel that supports the body "c channel", and the rear 2" of subfloor are all rusted, rotted toast. Gonners.

I will figure out a solid repair using information on these forums. The key is a strong "bridge" from street frame rail to curbe frame rail for a solid body attachment. The key is a design that won't let rain water to migrate between seams. The key is to use materials that resist oxidation and corrosion if wet.

David

David

My 66 Tradewind steel U channel had surface rust only yet the last 12" of my floor was rotted. The attached photo shows the repaired area with the black painted U channel and the front bumper cover that sits between the U channel and the floor. I believe the most important action we can take is to caulk the joint between the front bumper cover and the rear exterior shell using Trempro 635. This can be seen in the second photo. If this joint is sealed then the water can not get to the U channel and the floor.

Dan

[dbj216]

My Trade Wind was the same way. Floor was rotted but the rear cross member was good. My Overlander is a different story. Some previous owner used two tubes of Tempro back there and it was caulked real good, but too late. Caulk won't hold the frame rails up on a bouncy highway.

David

[dbj216]

Well, it's time to get serious about renovating this old Overlander. I've got the thing cleaned and inspected, the fridge out, the water heater out, and the toilet out. My mission is rear end separation repair and new waste water tanks.

Surprising to me the belly pan is actually attached to the "skid channels" at the rear of the frame. The existing tanks use this 7" high space for tanks and plumbing (5" frame channel, 2" skid channel). The belly aluminum covers the tanks. The belly aluminum is attached to the bottom of the bumper too forming the floor of the rear bumper "storage" compartment, except my trailer is full of holding tank drain plumbing.

This portion of the belly pan came down easily. There were no critter corpses found, except for a small mud dauber nest. But there was a lot of rust debris. Dust to dust as they say.

The waste water tanks are mounted next to each other at the very rear of the trailer. Both are in rusty pans. Both have rusty angle iron frames around the pans. And both angle iron frames are hinged in front, bolted in back. It appears I can remove the bolts and the angle iron frames will swing down the tanks fall out. We shall see.

Here is a photo of the waste water tank assemblies from the service manual to give you a feel for how it is built. I think it is pretty neat. Nothing cheap about this design.

Next job, remove the waste water tanks and see how easy they come out. Then I can inspect the frame rails for cracks and buckles. I'm nervous about that inspection.

David

[TouringDan]

Originally Posted by nickclifford

Or go with an on-demand .. $$$ but super nice. you must be from the old country ..?

I see no reason to go with an on-demand water heater unless you in a campground with full hook-ups. Even so, you need to pay much more money and have to deal with some of the operational,problems and it is not as reliable. Since we never camp with full hookups there is absolutely no reason to even consider an on-demand water heater. To each his own.

Dan

[dbj216]

I disconnected the vent lines and drain lines from both tanks. I removed the bolts holding the "swing down" tank frames and by golly, the tanks came down with the frames. Easy. I removed the fluid level wire harness and removed both tanks from the trailer.

I was not impressed with the U shaped black tank. I don't see how it could drain and flush completely. The grey tank is a 10 gallon tank. These were the very early years of holding grey water. Modern grey tanks are considerably bigger, and that's my plan.

I found it interesting both of these holding tanks were molded by Inca Plastics in California. They have been in business for a long time.

I found the black tank 3" female pipe spinweld plastic fitting broken when I removed the Thetford toilet. Someone tried to patch it to no avail.

With the tanks down and removed, I have a much better view of the rear cross member. The whole rear end attachment mechanism from the c channel on down needs replaced. There is also subfloor rot along the rear of the trailer. Not surpirsed.

Here are a few photos.

David

[dbj216]

The tanks are out of the trailer along with the rusted pans and frames. I have also removed the rusted rear cross member. I am currently shopping for nice sized black and grey tanks that will work in the spaces I have.

I have decided the bath has to come out to gain access to the rear body to frame bolts as well as a new plumbing routing to the new tanks.

The bath has a lot of plastic pieces, but it comes out okay. I was careful not to break anything. If a piece won't lift out, then there is still a rivet somewhere. I have yet to remove the tub, but it will come out as there are drain and vent lines underneath it.

I can see where I can reinforce some of the bath pieces for a little more stability back there.

David

[dbj216]

My Overlander had a "fire safe" lock box under the street side twin bed. I'm planning on using this space for the water heater in an effort to move some weight forward.

So I removed the lock box which was mounted on a piece of aluminum sheeting. I wanted to get that aluminum up so I could inspect the subfloor under it.

I uncovered a big old hole. Moisture is the bane of Airstream subfloors. This hole will be a straight forward repair. It may have been caused by a leaky window frame, or may have been caused by a poor seal between the wheel well and the outrigger. See photo below.

Interestingly, the back side of the aluminum sheet under this lock box was a "Do Not Enter" road sign. The "Enter" has been cut off to get it to fit in this space. I'll keep it in my shop. There are many things I can put under the "Do Not" portion of this sign.

What might you suggest?

David

[TouringDan]

David

Looks like your wheel wells are in very good shape. Some of mine had some very small rust holes. I thought about repairing them with fiberglass except that I had already painted them. In the end I just caulked over the holes and caulked the joint between the wheel well and the frame with Trempro 635.

I have part of an old highway “yield” sign that I can use if I need some heavy aluminum material to make stuff from. Must be a shortage of suppliers for this material. Somebody is missing an opportunity to make a bunch of money.

Dan

[dbj216]

The wheel well parts are in pretty good shape for the age of the trailer. The outriggers seem solid. But it does not appear the seam between the outrigger and the wheel well housing was sealed on either street or curb side. Towing at 60 mph in a North Carolina downpour sprays that seam like a power washer might. I wonder if that contributed to the floor rot.

Like you, I will caulk this seam. I will also plug any mouse holes between body and wheel well, both sides.

David

[dbj216]

This is the last piece of "furniture" in the rear bath. I decided I had to remove the bath tub to gain access to plumbing and body bolts.

The removal job isn't too bad. The rear bath furniture in my trailer is really quite well designed, and fits together nicely. I removed the tub P-trap from underneath the trailer (the belly pan is down giving good access) and then it is just a matter of finding all the pop rivets. The metal drain piece was rusted and broke while loosening it. I had to destroy it getting it apart. I will replace it with a new one, $10.

I do not know if Airstream or some previous owner sprayed expanding foam all over under the tub. It stuck to the tub support and made removal a bit harder than expected. There was no damage to the plastic tub when I yanked it up.

So now I have access to the drain and vent plumbing. There are fully three 1 1/2" ABS pipes running to two roof vents curb side for the galley drain line and the shower drain line. I am unsure why? My 86 Limited has just one vent line out of the gray tank. I plan to vent the galley drain and the shower drain with just one pipe each.

David

[dbj216]

I have removed all the old copper fresh water plumbing lines. I blew out the plumbing lines and opened the low point drains before I started. I was quite surprised at how much water was still in the lines as I began taking them apart. Blowing out the lines until there is no more water out of the faucets is not an effective winterizing technique. Low point drains are only partially effective in removing water. I will always pump in RV antifreeze until I get red at each faucet. That technique works for me.

There were three spots where some previous owner had to repair the copper due to freeze bursts. A lot of the plumbing runs are not very accessible if a leak does develop.

I have all the plumbing out from the fresh tank pump inlet to the city water inlet. I will install a modern pressure comp water pump, a modern 6 gallon electronic ignition water heater with bypass, a modern city water inlet, new faucets and new toilet. The fresh water plumbing system in this trailer will be all new. I'm doing this as the water heater was full of crud, the faucets ran slow, the toilet wouldn't hold water. I might as well replace it all "while I'm at it."

By the way, taking the fresh water plumbing system out of the trailer is easy. Re-plumbing in PEX will take considerably more time. This will be my third Airstream re-plumbing job. I much prefer PEX over copper.

David

[chrisetmike]

It is your 6th plumbing job! Now I know who to ask for help if I need it We are going to start with that soon too.

[Atomic_13]

Makes perfect sense. Steps like these will save you work/headaches later.

[dbj216]

My goal is to make this our "family" Airstream. I kinda, sorta wish it was a Trade Wind 25' as it would be a bit lighter and easier to maneuver for the sons. We have a heavy duty pickup in the garage that will pull it safely. The sons will learn to like pull through spots, not tight back in spots.

The extra room in the front living area will be a bit nicer I supose. And this trailer does have considerably more storage room inside, but not outside.

The rear end separation repair, the increased capacity holding tanks, the plumbing upgrade, the new axles, and the new appliances will make a week long vacation more enjoyable. Have a good time hiking instead of troubleshooting the water heater.

I might even enjoy a vintage Airstream rally now and then. : )

David

[Jim & Susan]

Ditto on the PEX. I will be interested to see what you do with the city water inlet. Hope you can post a couple pics.

Jim

[dbj216]

The 75 Overlander has the city water inlet mounted to the frame rail between the body and the bumper. It is 6" from the sewer connection, not good. And it is in the second dirtiest location on the trailer. I don't remember the dirtiest.

I just standard RV part for the city water inlet. It is a chromed plastic affair with a built in regulator and check valve. Good enough for me. I will mount it on the street side rear of the body where it is away from the sewer connection and out of the dirt.

Here is the one mounted on a previous trailer I had. It is below the electrical shore power connection.

David

https://www.vintagetrailersupply.com...-p/vts-621.htm

[nickclifford]

my '72 Landyacht "city" water connection is next to the black/gray dump valve.. never considered it a problem. Are you thinking contaminated waste could splash onto the valve inlet or something ? and contaminate the fresh water tank ? Don't see how that could happen?

[dbj216]

Hi nickclifford: Very likely not a problem. I do sometimes rinse the sewer connection at the dump station. The city water inlet was just located in a dirty, unhandy place on my Overlander in my view. I will move it because I prefer to move it. It is not a compelling reason.

You can see how low and close the city water connection is to the sewer connection in the photo below.

David