Jump to content

How difficult is it to remove a gas tank from one Sunrader and install it as a second gas tank in another Sunrader?


Stevo

Recommended Posts

Where on earth would you put it. Only place it could possibly fit is if you remove the grey holding tank in the back and mount it sideways. That 83 still has value. why make it worthless with no fuel tank and the 82 has less value without a working water system. .

Linda S

Link to comment
Share on other sites

How difficult is it to remove the gas tank from a 1983 21' Sunrader and install it in a 1982 18' Sunrader as a second tank?

Thanks

It would fit when mounted parallel to the original tank. But to do so, you'd have to re-route the exhaust sytstem which is not easy to do. Marine-grade stainless-steel flex pipe works well but it turns into a mess. Much easier to mount an square aux 15 gallon tank where the spare tire is now.

Link to comment
Share on other sites

What size tank do you currently have, 13 or 17.

I have a 17, it shows empty at around 14. I've run it all the way to empty, so I know its a 17.

I get a nice 3 hour drive time between gas stops, 55-60 mph, burning 4-5 gallons per hour, thats between 12 and 15 mpg. . I always carry a 2 1/2 gallon can of gas, The only time I've ever used it was when I intentially ran my tank empty so I knew exactly how the gas gauge behaved. (worst case, 2 1/2 gallons will buy me about 30 miles)

I've looked into adding a second tank where the spare used to be, either plumb it into the main tank, or just use a small electric pump to pump it into the main tank when the main starts getting low.. The more I drive mine, the less I get enthused about it.

( If your driving to Alaska, you'll need an extra 10 gallons)

JOhn Mc

Link to comment
Share on other sites

( If your driving to Alaska, you'll need an extra 10 gallons)

JOhn Mc

Depends on a person's lifestyle and travel habits. On many trips I like the ability of not being forced to buy overpriced gas on Interstates. Having an aux allows us to do that. We still stop along the way but are not forced to buy gas at an extra 20 or 30 cents per gallon. Same when we camp somewhere for a week or two and no gas is available locally. I've camped in areas for a week and no gas was available for 50 miles (one way, i.e. 100 miles round-trip). Having an aux allowed us to stay, camp, travel the area locally and not worry about running out. Also there have been many times when my tank was low and I was in an area I did NOT want to stop and get out. Having an aux used to let me drive from the NY, all the way through Canada and into Michigan without paying high Canadian gas prices. That is no longer an issue since their gas is sometimes cheaper than ours and I'm not allowed in Canada anymore, anyway. I still drive from NY to MI via the USA route 3-4 times a year and the last 5-6 hours of the trip are late at night and often with no open gas stations to be found. If someone has an RV with diesel - finding fuel in rural areas is even more difficult. Two years ago we travelled to an area to camp for two weeks in the eastern UP of Michigan. We got there with a 1/4 tank of fuel and found out the only fuel station in the area has closed up. We had to either park for two weeks - or just turn back. We turned back and camped closer to civilization. Now my diesel RV has two tanks and holds 80 gallons of fuel.

Your idea of having an aux tank to feed the main tank works well. It makes things much simpler on newer fuel injected vehicles. Once we wanted to take a trip from NY up and all over northern Canada. I had a 1983 diesel Chevy Blazer and pulled a 20 foot camper behind it. I got a 55 gallon sidetank from a big-rig. I put it on wood skids and stuck it in the back of the Blazer. I put a quick-disconnect hydraulic fitting on it. When the built-in main 45 gallon tank got low, I hooked up the aux and filled the main tank via gravity. Just had to be careful not to overfill. This gave us 100 gallons of fuel and we averaged 13.2 MPG for the entire trip. We made the entire trip without ever buying fuel. Note that when the Blazer pulled that camper without the 55 gallon tank sitting in back it still got 13 MPG. There was no measurable change in fuel mileage.

Link to comment
Share on other sites

It would fit when mounted parallel to the original tank. But to do so, you'd have to re-route the exhaust sytstem which is not easy to do. Marine-grade stainless-steel flex pipe works well but it turns into a mess. Much easier to mount an square aux 15 gallon tank where the spare tire is now.

I want to qualify my own statement. I assume not all Toyota RVs have a spare underneath. My statement is only meant to apply to those that do.

Link to comment
Share on other sites

I want to qualify my own statement. I assume not all Toyota RVs have a spare underneath. My statement is only meant to apply to those that do.

Both of my 18ft Sunraders do have a spare underneath. I don't think extra tanks will pass the smog inspections in California though and that is where Stevo is. Pretty strict out here.

Linda S

Link to comment
Share on other sites

I know CA is bad. Even more regs then NY. I wonder though if there are exemptions for aux tanks installed as "storage" tanks instead of aux tanks. ( I don't pretend to know). I assume the fear about aux tanks is changing emissions equipment. If a tank was installed in a way that it was only for "storage" and not plumbed into the fuel system - I wonder if it would be exempted (like Waiter mentioned earlier). That's kind of good way to do it anyway IF the rig has electronic fuel injection. Otherwise you'd need a 2nd high-pressure EFI pump, a selector valve, etc. What happens in CA when you have a 5 gallon gas can strapped to the back of the RV? I'm almost afraid to ask since California caused the good-old vented 5 gallon portable gas cans to pretty much disappear. Now we have to spill more gas then ever before using these insipid "California" cans. I finally punched holes in all mine and installed my own "illegal" vents. I spill a lot LESS fuel that way.

Link to comment
Share on other sites

I've done the aux tank before. also on airplanes when we do ferry tanks.

Plumb the aux tank in with its own filler neck and vent, then use a small electric pump to pull it out of the aux, install a "T" in the main tanks vent line as close as you can to the main tank. Connect the pumps output to the "T". When you see the main running low, turn on the pump. Just don't forget to turn it off or you overfill the main and dump your fuel overboard.

If the pump has a backflow valve (most do) the main tank will still pass smog pressure test for all you Calif people.

Ferried many planes like this..

John Mc

88 Dolphin 4 Auto

Link to comment
Share on other sites

I'm not sure where I would put it yet but will have more ideas for possibly doing it after I've spent more time underneath while doing the axle swap. The 83's value for me now is that it is a donor vehicle for my 82. Why should I spend hundreds more on stuff like the axle, hood, front bumper, side mirrors and possibly a gas tank when I can take it off the 83? Besides, the 83 will still have value for someone that can do the work on it themselves or has a friend or family member that will do it for them for free or cheap...and as long as it can roll, the Sunraders fiberglass house will always be of value to someone too. As far as the existing water tank, well, since the interior is going to be radically different than it is now, that might get moved or changed out for something else as I move along with this project...

Where on earth would you put it. Only place it could possibly fit is if you remove the grey holding tank in the back and mount it sideways. That 83 still has value. why make it worthless with no fuel tank and the 82 has less value without a working water system. .

Linda S

My 82 might require a new exhaust system anyway as it looks pretty funky right now. What is it about marine grade stainless steel flex pipe that turns into a mess? If I put it where the spare tire is now do you have any suggestion where I could hang the spare tire?

It would fit when mounted parallel to the original tank. But to do so, you'd have to re-route the exhaust sytstem which is not easy to do. Marine-grade stainless-steel flex pipe works well but it turns into a mess. Much easier to mount an square aux 15 gallon tank where the spare tire is now.

I'm not sure what size the tanks are yet.

What size tank do you currently have, 13 or 17.

JOhn Mc

I will be titling and registering this vehicle in South Dakota so CA's smog stuff won't apply here.

Both of my 18ft Sunraders do have a spare underneath. I don't think extra tanks will pass the smog inspections in California though and that is where Stevo is. Pretty strict out here.

Linda S

Link to comment
Share on other sites

Is there any reason I couldn't connect the aux tank to the main fuel tank with a hose between the two of them located at the bottom of each tank? Any disadvantages to doing that?

Link to comment
Share on other sites

My 82 might require a new exhaust system anyway as it looks pretty funky right now. What is it about marine grade stainless steel flex pipe that turns into a mess? If I put it where the spare tire is now do you have any suggestion where I could hang the spare tire?

All I meant by that is it is not an easy thing to do for someone without the proper tools and know-how. I have no idea what your skill level is, if you own a set of torches, etc. No insult intented but not every on these forums has high mechanical skills and a well equipped shop. I can't imagine doing any sort of exhaust work without a set of torches since exhaust hardward tends to get very stuck.

I had considered putting a 2nd OEM Toyota tank in mine - in place of where the muffler is now. It was doable but I decided to use the spare-tire location instead since I want my spare mounted in front anyway (where it's easy to get at and check pressure).

If you get some 1 3/4" ID marine-grade SS (the high-grade SS for salt-water use) - and remove the muffler - you can swing the exhaust outside the frame rail and run it to anywhere you've got room for a muffler. The marine-grade SS pipe for some reason is gettting harder and harder to find. I used to buy it from J.C. Whitney and they offered it in two types of SS grades. I've got it on a truck exhaust system I built 20 years ago and plow snow every winter with it. The flex-pipe still looks like new. So do my SS mufflers that were $150 apiece 20 years ago (Dynomax Ultraflo SS). If you buy galvanized steel flex pipe like most auto-parts sell - it will rot out in one year.

This place has the SS flex pipe in 1 1/2", 2", 2 1/2", etc. but no 1 3/4" listed. J.C. Whitney used to have the 1 3/4", but seems no more. I've been buying from them for over 50 years - but it seems they are going in a different direction and more "upscale" in my scale of relativity.

http://industrial-rubber-hose.abbottrubber.com/viewitems/hose-exhaust-ventilation-hose/flexible-metal-exhaust-stainless

Link to comment
Share on other sites

As long as the bottom of the aux tank is higher than the bottom of the main tank. AND it has a separate filler it should work. Don't forget to connect the vent lines to each other too.

Fill main tank first, then aux, then top off main. A remote fuel solenoid would eliminate the juggling.

WME

Is there any reason I couldn't connect the aux tank to the main fuel tank with a hose between the two of them located at the bottom of each tank? Any disadvantages to doing that?

Link to comment
Share on other sites

Is there any reason I couldn't connect the aux tank to the main fuel tank with a hose between the two of them located at the bottom of each tank? Any disadvantages to doing that?

I can't think of a reason why not. My 1964 Sunbeam Tiger came new that way. It had two peanut-sized gas tanks in the trunk. One on each side and connected by a "equalizer" cross-pipe. Just one tank had a fuel sender in it.

Oddly my 1995 Subaru has what in effect is two small tanks with a joining tube but the Subaru has two sending units. I guess it reads both and presents an average reading on the dash. Not something I ever gave much thought to since it works.

You might find filling the tanks a little slow-going with vapor backup and shut-offs while trying to fill unless you take your time.

Link to comment
Share on other sites

Is there any reason I couldn't connect the aux tank to the main fuel tank with a hose between the two of them located at the bottom of each tank? Any disadvantages to doing that?

No, shouldn't be. but you should connect the vents together also.

Maybe use a 3/4 ID hose as close to the bottom as you can get, and a 1/4 or 1/2 hose at the top for the vent. A large diameter hose at the bottom should allow the fuel to flow to the aux tank fast enough to keep up with the gas station pump.

JOhn Mc

88 Dolphin 4 Auto

Link to comment
Share on other sites

Hah hah, no offense taken - and I am one of those with zero experience dealing with exhaust stuff. I'll know more about the exhaust as I progress with the axle swap but I can see already that it was a very half-behind job.

If you were going to be driving in the tropics or anywhere else that gets really hot, wouldn't you be concerned about blocking air flow to the radiator if you mounted the spare tire on the front bumper?

All I meant by that is it is not an easy thing to do for someone without the proper tools and know-how. I have no idea what your skill level is, if you own a set of torches, etc. No insult intented but not every on these forums has high mechanical skills and a well equipped shop. I can't imagine doing any sort of exhaust work without a set of torches since exhaust hardward tends to get very stuck.

I had considered putting a 2nd OEM Toyota tank in mine - in place of where the muffler is now. It was doable but I decided to use the spare-tire location instead since I want my spare mounted in front anyway (where it's easy to get at and check pressure).

If you get some 1 3/4" ID marine-grade SS (the high-grade SS for salt-water use) - and remove the muffler - you can swing the exhaust outside the frame rail and run it to anywhere you've got room for a muffler. The marine-grade SS pipe for some reason is gettting harder and harder to find. I used to buy it from J.C. Whitney and they offered it in two types of SS grades. I've got it on a truck exhaust system I built 20 years ago and plow snow every winter with it. The flex-pipe still looks like new. So do my SS mufflers that were $150 apiece 20 years ago (Dynomax Ultraflo SS). If you buy galvanized steel flex pipe like most auto-parts sell - it will rot out in one year.

This place has the SS flex pipe in 1 1/2", 2", 2 1/2", etc. but no 1 3/4" listed. J.C. Whitney used to have the 1 3/4", but seems no more. I've been buying from them for over 50 years - but it seems they are going in a different direction and more "upscale" in my scale of relativity.

http://industrial-rubber-hose.abbottrubber.com/viewitems/hose-exhaust-ventilation-hose/flexible-metal-exhaust-stainless

I don't think it would be possible to mount the aux any higher than the main gas tank if I install it under the vehicle. To avoid the expense and hassles, I'm hoping I wouldn't have to install a separate filler.

As long as the bottom of the aux tank is higher than the bottom of the main tank. AND it has a separate filler it should work. Don't forget to connect the vent lines to each other too.

Fill main tank first, then aux, then top off main. A remote fuel solenoid would eliminate the juggling.

WME

Don't you think the line connecting the aux to the main fuel tank should be substantially larger than only 3/4" ID? I was thinking of something more like 1 1/2" ID so there wouldn't be that bottleneck there when filling up. What do you think?

No, shouldn't be. but you should connect the vents together also.


Maybe use a 3/4 ID hose as close to the bottom as you can get, and a 1/4 or 1/2 hose at the top for the vent. A large diameter hose at the bottom should allow the fuel to flow to the aux tank fast enough to keep up with the gas station pump.

JOhn Mc

88 Dolphin 4 Auto

Link to comment
Share on other sites

Obviously, larger would be better, but remember, for every gallon your pumping into the main, about 1/2 of that will flow into the aux. Get the biggest you can get, but I think you want at least 3/4 ID. To give you an idea of how fast gas would flow thru the 3/4 hose. think about how fast gas flows out of a gas can filler spout. (And Not one of those crappy EPA approved filler spouts)

John Mc

88 Dolphin 4 Auto

Link to comment
Share on other sites

  • 4 weeks later...

Have you thought about having a tank custom built? It can get pricy though.

Sell the one you were going to pull the tank from and use that money for the new tank. This way the tank wil custom fit the location. Just a thought. Sometimes all the work it takes to pull the tank, fit it and install it doesn't add up.

Link to comment
Share on other sites

  • 3 months later...

I have an 86 Sunrader with a 27 gal tank. Just 4 bolts. This past spring I took it to Tank-Renew. (a franchise chain) I old rusted tank look brand new. This tank was a Sunrader upgrade. The used the toyota factory pump and sending unit. Still working on the guage reading.

post-6742-0-40839700-1361357932_thumb.jp
Link to comment
Share on other sites

New 26 gallon tanks are available for about the same price as you paid to have yours restored.

http://www.nwmp.com/index.php?option=com_content&view=article&id=110:lwb-pick-up-2-a-4-w-drturbo-injection-1985-1987&catid=11:toyota&Itemid=23

The only thing is you can't tell them it's for a motorhome. For some reason these guys think a motorhome puts more stress on a tank than an off road 4x4. I think that is silly but what do I know

Linda

Link to comment
Share on other sites

Nice find Linda. I was quoted $1,500 plus shipping to have a new tank made by Transfer Flow, the original manufacturer. It's not a Toyota Tank. Gardner-Pacific clearly modified the under body to make this fit. With the help of a transmission stand, it's easy off and easy on. Sorry to go off subject, My big issuse now is the guage reading. On the first full tank of gas, after a 5 min delay at 1/2, the new sending unit worked and the guage read full. It seemed to read properly as the tank emptied. On the second tank, it took about 20 mins for the guage to read full. About 1/2 through that tank, the guage dropped to E. I refilled the tank and it stayed at E. Took it back to the shop, removed the brand new sending unit, manually operated it and it worked. There are no obstructions like the baffle. It's reading 1/2 now but I think the tank is full.

Crazy. The old sending unit float arm was modified by someone. The new stock toyota unit seemed to be nearly identical to the old modified one, and it worked on the 1st tank. Any suggestions? Here's the New and the Old.


post-6742-0-70134800-1371538661_thumb.jppost-6742-0-74251100-1371538800_thumb.jp

Link to comment
Share on other sites

  • 2 weeks later...

I'm not sure where I would put it yet but will have more ideas for possibly doing it after I've spent more time underneath while doing the axle swap. The 83's value for me now is that it is a donor vehicle for my 82. Why should I spend hundreds more on stuff like the axle, hood, front bumper, side mirrors and possibly a gas tank when I can take it off the 83? Besides, the 83 will still have value for someone that can do the work on it themselves or has a friend or family member that will do it for them for free or cheap...and as long as it can roll, the Sunraders fiberglass house will always be of value to someone too. As far as the existing water tank, well, since the interior is going to be radically different than it is now, that might get moved or changed out for something else as I move along with this project...

My 82 might require a new exhaust system anyway as it looks pretty funky right now. What is it about marine grade stainless steel flex pipe that turns into a mess? If I put it where the spare tire is now do you have any suggestion where I could hang the spare tire?

I'm not sure what size the tanks are yet.

I will be titling and registering this vehicle in South Dakota so CA's smog stuff won't apply here.

Hi all,

Here is an alternate idea, that has a lot of advantages; flexible tanks (sewage water or gas) - they were originally designed for sail boats but have been approved in some cases to be installed in vehicles. The advantage is that you can drop them into an interior space (say after removing your original fuel tank) and because they expand to fill the void can fit where metal tanks are too bulky, they are easier to install. Here is a link to a site that offers a number of companies that offer one or more types of tanks - http://www.ahoycaptain.com/flexiblefueltanks.html - look up flexible tanks on the internet - there are lots of them offered for sale.

Boots

Link to comment
Share on other sites

I pulled out that other gas tank last week (finally). I'm not sure yet how I will install it (if I do) but the only place I can see to put it is where the spare tire is (18' Sunrader). If I put it there do you have any suggestions for where the spare tire could go?

Link to comment
Share on other sites

This locks on to your 4 inch sewer hoser carrier bumper. Sunrader frame extensions are very strong. I wouldn't worry about the weight of just one tire and wheel

http://www.campingworld.com/shopping/item/Universal-RV-Tire-Carrier/64844/&?&affiliateid=3274&cvsfa=2734&cvsfe=2&cvsfhu=3634383434&gclid=CN_G3efXibgCFSU6Qgod9noAZA

Buy a nice cover to put over it and it could look pretty nice

Linda S

Link to comment
Share on other sites

My big issuse now is the guage reading. ... Any suggestions?

I took a careful measurement of the tank depth. Clamped the sending unit to my bench and adjusted the arm angles until it measured exactly the tank depth. Small changes in angle made big changes in depth.

I also turned the fuel pump around so it points foreward to the low end of the tank, and drilled new holes to drop the pickup as low as possible.

My guage now reads at F when full, and I have about a gallon reserve left when it drops off the Low mark. Bottom edge of E mark to bottom edge of F mark takes 21.5 gallons. 22.5 gallons when it was cutting out on corners or on the uphill of the overpass. Haven't run it to dry yet.

The re-do item on my list: When I replaced the filler hose, I messed up the angle of the hose. The nozzles no longer shut off in time, and unless I am Real careful I get spillage. The Oregon gas jockeys do not like it. I have to get it pointed downward more, I think.

Link to comment
Share on other sites

Good idea. Thank you Linda.

This locks on to your 4 inch sewer hoser carrier bumper. Sunrader frame extensions are very strong. I wouldn't worry about the weight of just one tire and wheel

http://www.campingworld.com/shopping/item/Universal-RV-Tire-Carrier/64844/&?&affiliateid=3274&cvsfa=2734&cvsfe=2&cvsfhu=3634383434&gclid=CN_G3efXibgCFSU6Qgod9noAZA

Buy a nice cover to put over it and it could look pretty nice

Linda S

Link to comment
Share on other sites

Did you add a second tank or just replace the existing with a larger tank?

I took a careful measurement of the tank depth. Clamped the sending unit to my bench and adjusted the arm angles until it measured exactly the tank depth. Small changes in angle made big changes in depth.

I also turned the fuel pump around so it points foreward to the low end of the tank, and drilled new holes to drop the pickup as low as possible.

My guage now reads at F when full, and I have about a gallon reserve left when it drops off the Low mark. Bottom edge of E mark to bottom edge of F mark takes 21.5 gallons. 22.5 gallons when it was cutting out on corners or on the uphill of the overpass. Haven't run it to dry yet.

The re-do item on my list: When I replaced the filler hose, I messed up the angle of the hose. The nozzles no longer shut off in time, and unless I am Real careful I get spillage. The Oregon gas jockeys do not like it. I have to get it pointed downward more, I think.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...