First a cracked gray tank, now a cracked black tank...

[JDBrown]

I'm new to this, but learning fast (unfortunately, not all of the lessons are pleasant). After years of idly dreaming of having a Class B, I bought a 1999 Roadtrek Versatile 190 a few weeks ago. Now I'm working my way through the effects of the previous owner's neglect.

My question is, are the holding tanks on these vans prone to frequent cracking?

My van arrived with a small crack (looked more like a cut, really) near the top of the gray tank. I pulled the gray tank off (not an easy task), patched it, and put it back on. Then I filled both holding tanks, didn't see any leaks, and figured I was good. Took the van out for a weekend trip, and was met with the nice surprise of a leaking black tank when I went to dump it.

I was adding water through the toilet before dumping and the tank seemed to be taking forever to fill. Then I looked under the van and saw water and toilet paper pouring down from the tank (crack must be big). So, I'm going to have to pull the gray tank off again just to get to the black tank. Then I may have to drop the black tank as well, depending on where the crack is.

Is this normal/to be expected? I realize it's 20 year old plastic, but there seem to be plenty of people driving older RT's so I can't imagine they're all that brittle. And as far as I know the tanks were custom made by RT, so I can't just go buy a replacement. Did I abuse it by driving on a couple of dirt roads?

[hbn7hj]

I would say no. Mine are 17 years old with no failures. I even hit one once. Over time it straightened back out and all was well.

Previous owner could have had them full of water in the winter. As you have found out it is no small task to remove them. The tank hangars don’t take any twisting. Cut the nuts off.

[GallenH]

My 1997 is older than yours and I haven't noticed any problems. I've driven for miles (sadly!) on very rough roads. Just to be clear, did you say that you filled both holding tanks and did you mean grey and black? Or grey and fresh?

[JDBrown]

Originally Posted by hbn7hj

I would say no. Mine are 17 years old with no failures. I even hit one once. Over time it straightened back out and all was well.

Previous owner could have had them full of water in the winter. As you have found out it is no small task to remove them. The tank hangars don’t take any twisting. Cut the nuts off.

Thank you for the reply and the reassurance. Hopefully this is the last time I'll have to pull the tanks off.

I've taken the nuts off the tank hangers within the last 2 weeks and only had to cut one off (lots of WD-40 plus some ATF), so I'm pretty confident they won't be a problem now.

[JDBrown]

Originally Posted by GallenH

My 1997 is older than yours and I haven't noticed any problems. I've driven for miles (sadly!) on very rough roads. Just to be clear, did you say that you filled both holding tanks and did you mean grey and black? Or grey and fresh?

Gray and black. For the record, I've filled the fresh tank too with no leaks.

Thanks for the reassurance, it gives me hope that I won't have to do this again any time soon.

[GallenH]

Yeah, I would guess that if you pull the tanks and repair or replace them, you'll never have to do it again.

Incidentally, my father in law who owned the RV before us put a fiberglass patch on the fresh water tank. It's held for probably 10 years or more. He was the master of fiberglass repairs........mostly of his boats that would occasionally bounce down the road when he failed to completely secure them.

Good guy. May he RIP.

[rowiebowie]

Yes, 20 yrs can take its' toll on man & machine.

I'd hit the character limit of a post if I listed all the repairs I've done to my "b" which is a little less than half the age of yours. The good news is I'm now intimately familiar with my van and so far the same things haven't broke twice.

I'll venture a guess that the toilet line detached from the top of the black tank.

[JDBrown]

Well, after struggling with it for most of the night, I finally managed to get the black tank off. And... it's MELTED!

https://ibb.co/GtmNHD7

I don't know how this happened -- my engine temp has been fine, although I don't know if that really correlates with muffler/exhaust temp. In this photo the black tank is on top, muffler on bottom. I assume the piece of sheet metal between them is a heart shield intended to prevent this sort of thing from happening.

https://ibb.co/rF83Q0v

Any ideas on how to approach fixing this mess? Suggestions for how to prevent it from happening again?

[rowiebowie]

Yes, heat shields should keep such damage from occurring.

[JDBrown]

If the heat shield was touching the tank, could that cause this?

[rowiebowie]

Originally Posted by JDBrown

If the heat shield was touching the tank, could that cause this?

I'll have to let someone with your model answer that one. You're correct, the heat shield should not touch the tank. But in the picture is certainly looks close. But how did it last this long if that was the problem?

It looks to have gotten crazy hot, like parked over a fire hot. Finding a replacement is the biggest problem. But you're certainly demonstating you have the skill to work on it. Good luck.

[hbn7hj]

heat shield, fiberfrax, and high temp tape. I have the fiberfrax.

I melted all my plumbing but didn't damage the tanks.

fiberfrax is a high temp ceramic insulation

[hbn7hj]

You need heat shields, an air gap, and insulation. Roadtrek only provided the heat shield and the air gap.

[booster]

You may want to check a couple of things on the van that might do something like that, beyond the good suggestions that have already been made.


Take a look at the pipe and muffler in that area to make sure there isn't a leak in that area that would put hot exhaust on the area. You probably would see some soot if it did do that.


Take a look at exhaust pipe for signs of a rich mixture, which could be intermittent, right after the catalytic converter to see signs of heat. Rich mixtures, especially at idle can cause some very severe heat issues around the converter and after it.



As far as I recall, we haven't heard of the Dodges having heat and melting issues. The pipes on some of the early Chevies, yes.

[JDBrown]

Originally Posted by hbn7hj

heat shield, fiberfrax, and high temp tape. I have the fiberfrax.

I melted all my plumbing but didn't damage the tanks.

fiberfrax is a high temp ceramic insulation

Is fiberfrax a fiberglass blanket insulation? How do you attach it?

Should I be trying to glue insulation to the sheet metal heat shield (maybe with RTV silicone)? Or should I just focus on insulating the muffler and exhaust pipe (maybe with some of that 2" wide fiberglass that you wrap around the pipe)?

Originally Posted by booster

Take a look at the pipe and muffler in that area to make sure there isn't a leak in that area that would put hot exhaust on the area. You probably would see some soot if it did do that.

Take a look at exhaust pipe for signs of a rich mixture, which could be intermittent, right after the catalytic converter to see signs of heat. Rich mixtures, especially at idle can cause some very severe heat issues around the converter and after it.

I'll check for holes and soot when I crawl back under the van after work this evening.

I'm afraid I don't know what signs of heat I should be looking for after the catalytic converter. Discoloration? Can you elaborate? Also, shouldn't I be getting a check engine light if the engine is running rich enough to cause this much heat? Or is the idea that if the computer screws up and dumps in too much fuel, it's not going to realize its own mistake?

On the trip this last weekend I drove up some long, steep hills that had me going 15 mph in 1st gear with OD off and the gas pedal at or near the floor. Could that have something to do with this? Is it possible I just pushed the van too hard? I was keeping a close eye on engine temp and it was totally fine the entire time, but I never even considered that the exhaust temp might be a problem.

[booster]

Originally Posted by JDBrown

Is fiberfrax a fiberglass blanket insulation? How do you attach it?

Should I be trying to glue insulation to the sheet metal heat shield (maybe with RTV silicone)? Or should I just focus on insulating the muffler and exhaust pipe (maybe with some of that 2" wide fiberglass that you wrap around the pipe)?



I'll check for holes and soot when I crawl back under the van after work this evening.

I'm afraid I don't know what signs of heat I should be looking for after the catalytic converter. Discoloration? Can you elaborate? Also, shouldn't I be getting a check engine light if the engine is running rich enough to cause this much heat? Or is the idea that if the computer screws up and dumps in too much fuel, it's not going to realize its own mistake?

On the trip this last weekend I drove up some long, steep hills that had me going 15 mph in 1st gear with OD off and the gas pedal at or near the floor. Could that have something to do with this? Is it possible I just pushed the van too hard? I was keeping a close eye on engine temp and it was totally fine the entire time, but I never even considered that the exhaust temp might be a problem.

On rusty stuff it is often hard to see the telltale bluish tint from heat, but sometimes the rust or corrosion will have shocked off from it. Converters are stainless steel so more likely to show it, plus distortion sometimes.


These days that converter overheat usually would be a computer or sensor failure, so it thinks all is good when it isn't, and you will get high exhaust temps going up under those conditions as you are generating a lot of heat and have less speed to cool the things under the van.


It is quite easy to make new or more heat shields yourself and only takes a decent tinsnip or aviation snip set. Use the light gauge galvanized sheet you can get at the hardware store and a couple of the right size muffler clamps to fit the exhaust. Cut a rectangle of the sheet to the size you want, then cut about a 1/2" wide strip about 2" in, dead centered from each end, still attached by the 1/2" at the end of the strip. Bend the strips down at near 90 degrees and then halfway out them up to make parallel to main part. You can use those two strips to mount the shield to the pipe with the clamps, adjusting the heights to what you need to clear by how the strips are bent. It usually is better if you put a bit of a bend or two the length of the shield to "wrap around" the pipe a small amount. I have done lots of them that way and they have worked well.


Exhaust pipes get hot on vehicles, I have seen lots of melted mud flaps on vehicles, where they wound up hitting the pipe where it comes out be the rear wheel like on the Chevy vans.

[rowiebowie]

Originally Posted by JDBrown

On the trip this last weekend I drove up some long, steep hills that had me going 15 mph in 1st gear with OD off and the gas pedal at or near the floor. Could that have something to do with this? Is it possible I just pushed the van too hard? I was keeping a close eye on engine temp and it was totally fine the entire time, but I never even considered that the exhaust temp might be a problem.

Definitely doesn't sound right. Maybe a clogged catalytic converter. If so, it would have been glowing red-hot. Don't know if the catalytic converter is near enough to the tank or not. I'm surprised the engine temperature stayed good, but tell a mechanic and get this problem checked out.

[hbn7hj]

Originally Posted by JDBrown

Is fiberfrax a fiberglass blanket insulation? How do you attach it?

Should I be trying to glue insulation to the sheet metal heat shield (maybe with RTV silicone)? Or should I just focus on insulating the muffler and exhaust pipe (maybe with some of that 2" wide fiberglass that you wrap around the pipe)?

Fiberfrax is a ceramic that looks like cotton. It is fragile and has to be covered.

I would send you some but I'm not home. I used it in homebuilt aircraft as a firewall insulator, 1/16” with aluminum sheet. Lighter than stainless steel.
I have a large quantity of 1/2” stuff left over from my debacle.

I used 1/2” stuff around RV plumbing wrapped in hi temp tape. Air space between heat shields is the most important item. You could put fiberfrax between two steel sheets to make a heat shield. You would have to tape the edges because if it absorbed oil it could be a fire starter.

Fiberglass is not a high temp insulator. Better to have an air gap.

Do not insulate an exhaust pipe without an air gap. The pipe will disintegrate. There is a product for that. I'll look for a link. It comes in 3ft. lengths with stainless steel hose clamps for the standoff.

https://www.google.com/shopping/prod...93406672&psb=1

Again, a steel heat shield with an air gap is where you start. After that you can wrap your tank with the Fiberfrax if you must but even then you need the air gap to the heat shield to carry off the heat.

Do not glue insulation to anything. It may burn. You could wrap it with high temp tape. The Fiberfrax vendors have it.

[booster]

I used hot rod style header insulating wrap our exhaust pipe where it goes past the rear hung batteries, plus a couple of home made sheet metal shields and it seems to be working well so far. If you are worried about moisture in the header wrap issues, you should be able to find some special paint to water proof it that works pretty well. If the exhaust is stainless, no issue, that is what we have on the Chevy.

[InterBlog]

I'm late to this party, but the OP is talking about the tank itself cracking? Not the joinery?

Different model I know, but first generation Airstream Interstates are notorious for piping splits. They were plumbed without any way of allowing for flexure during rough rides. The very first big DIY job that my husband and I did was to re-plumb most of our system because most of the connections had been sheared apart.

If the OP replaces one or more tanks, I would recommend a similar provision be evaluated, and also maybe add a relief valve to any tank that could disgorge an overflow into the van itself, if that is a possibility in his/her model.

It might not have been plumbed that way to start with, but if you are in for a penny, you might as well go in for a pound, so that it could never morph into a new problem down the road.

You can read about our plumbing retrofits here.