Changing out the Alde fluid.

DanWeitzel · December 2023

I used the shop vac method with good results on our 2016 T@B. Sucked it all out thru the expansion tank than refilled the same. Ran the circ pump on high speed for about half an hour to get the air out. Reset the circ pump to #2 speed, all worked good. System was completely drained as I removed all convectors and metal connections to fix corrosion issues.

tombeaux · December 2023

Same. And if you want to check for corrosion, it’s SO much easier if the system is empty.

ReenieG · December 2023

ScottG said:

@ReenieG, have you seen this DIY Alde Glycol Exchange document? It contains more details about the parts and process for constructing the pump.
Also, if you have the patience to read through the entirety of this discussion, you will see that owners have come up with several other equally effective approaches to getting the glycol exchange job done. If you elect not to go the pump route, you may find an alternative you are more comfortable with.

@ScottG I hadn't seen that DIY before now so thank you for pointing that out. Thank you

ReenieG · December 2023

pthomas745 said:

@ReenieG I have a 2017 with the same setup on the expansion tank, which makes it practically impossible to use the basic pump setup included in the "DIY Glycol Exchange" that has been developed in this thread. Even if the pump setup was modified for more flexible hoses into the tank, it would still be difficult to see that the hoses were properly placed, etc. Even with the entire back cabinets removed, it still would not be an easy task.
But.....
There is one small section of this long thread which shows a much easier way to do the exchange. On page 15, Scott G points out that disconnecting the hose that comes off the Auto Air Bleed Valve essentially gives you control over the entire glycol loop (or at least most of it) and you can push the glycol out from that point, and refill from that point also. On page 19, owner @BrianZ accesses the glycol loop in about the same spot with a more elaborate exchange setup.
https://tab-rv.vanillacommunity.com/discussion/comment/165276/#Comment_165276
Several owners near page 15 successfully used that place on the Alde to do the exchange, and reported no issues. I plan on trying this method in the next few weeks.

@pthomas745 I definitely like your "but."

I will check that out for sure. I think I will still have to remove the cabinets to inspect what I'm feeling and seeing underneath there where the convectors are but that's a whole 'nother discussion, I'm (sort of) sad to say. :( Anyway... I checked out the link you shared and that is WAY more doable, imo. Thank you for sharing and @ScottG, thank you for posting.

I will however in all likelihood still need to remove my cabinets to inspect how much corrosion I have and if any leak repairs will be required after doing a field test of my Alde system.

I do have a question about my reservoir tank, if anyone knows... the cap on mine is cardboard in the center and it spins when you try to tighten it. It's always been that way. I bought my T@B used from a dealer so I'm wondering if that is not the right cap. Basically, it's almost like a loose lid that doesn't screw on right.

This is why I'm thinking the spillage and/or corrosion might/could be caused by my trailer jostling around on a bumpy dirt road causing some fluid to leak out since there were drips in the pic I took of my tank. Of course I could have dripped some while filling, but what if those streaks of dusty glycol down the back under the seat and what I see of some corrosion could be from glycol repeatedly spilling out and running down the rubber tubing. I think it's quite possible that's what it could be, and imho, just as likely as a leak. What do you all think? Any thoughts on this? TIA

manyman297 · December 2023

My lid is loose like that as well. I believe it may be a safety feature in case the system does get completely blocked up (including the overflow tube) so it can let off pressure from the system.

ReenieG · December 2023

@manyman297 ok, good to know! Thank you. I still think it odd my lid has cardboard in the center though, lol.

manyman297 · December 2023

I don’t remember if mine does or not. It definitely doesn’t screw on tight though.

ReenieG · December 2023

I'll take a pic of my cap and post it here when I go back out to the storage.

bergger · December 2023

Yeah my our cap is loose as you describe but no cardboard. From what I remember it is a solid plastic cap.

ReenieG · December 2023

@bergger, here's my cap. The black center is a piece of cardboard lol.

Image: https://us.v-cdn.net/5021717/uploads/editor/ec/0kfoi2i3pdhq.jpg

ScottG · December 2023

IIRC, mine (2015) looks like yours, @ReenieG, though I'm not sure if it's actually cardboard or something else (maybe a rubber disk?) in the center.

AnOldUR · December 2023

ScottG said:

... maybe a rubber disk ...

On our 2020 320S we had the same problem. As soon as I'd get the cap snug, the threads would disengage and it would be lose. It had the rubber gasket that @ScottG talks about. I removed the gasket and it allows for just enough more thread engagement that it can be tightened and doesn't leak.

bergger · December 2023

I'll have to look at mine again just to make sure. Pretty sure it's solid plastic but now you guys have me doubting that!

manyman297 · December 2023

@ReenieG
I have to wonder if you're not getting glycol splashing out of that cap and overflow tube? It's also interesting they didn't run the overflow tube out of the bottom of the camper (in the 400 they run it down through the floor out the bottom so it drains to the outside. And I've seen evidence of glycol making its way up/down that overflow tube to the outside (probably just the jostling of the camper on rough roads) so it does happen.

AnOldUR · December 2023

@manyman297 I'm not sure if they're all the same but mine has two tubes. One is a overflow tube and is a little lower on the tank. The tube in the picture posted above by @ReenieG would be where my the vent tube is located, not the overflow that runs out the bottom of the trailer.

edit to add that I routed the vent tube to a cup just in case any glycol made its way out.

Image: https://us.v-cdn.net/5021717/uploads/editor/yq/i1e8ygc7bunf.jpg

ScottG · December 2023

AnOldUR said:

ScottG said:

... maybe a rubber disk ...

On our 2020 320S we had the same problem. As soon as I'd get the cap snug, the threads would disengage and it would be lose. It had the rubber gasket that @ScottG talks about. I removed the gasket and it allows for just enough more thread engagement that it can be tightened and doesn't leak.

@AnOldUR, didn't removing the disk/gasket leave a big hole in your cap? Or do you have a solid cap like @bergger describes?

AnOldUR · December 2023

ScottG said:
@AnOldUR, didn't removing the disk/gasket leave a big hole in your cap? Or do you have a solid cap like @bergger describes?

Looks like there are different caps used by nuCamp. Mine was solid with a rubber gasket.

Image: https://us.v-cdn.net/5021717/uploads/editor/a2/6i9b2ikzbv3j.jpg

Image: https://us.v-cdn.net/5021717/uploads/editor/ne/srmu3o7mezxk.jpg

ReenieG · December 2023

@ScottG I'm pretty sure it's cardboard. I felt it many times. It's just weird imo.

ReenieG · December 2023

@manyman297 I believe there's another tube under the bench which runs down the bottom of the trailer. I'm in agreement with you on the jostling though. I'm gonna keep my eye on what's happening closer this next week of camping 🏕 so hopefully I'll have more information before I do a glycol flush.

manyman297 · December 2023

@AnOldUR @ReenieG
You’re probably right about the two tubes now that I think about it. One is a vent (and I think mine is racked to the sidewall pointing straight up) and the other is the overflow. I’d verify but it’s too d*mned cold to go outside and do it right now!

pthomas745 · December 2023

I have a 2017, with the tank in the "dead" corner on the driver's side. Just went out and looked, and my cap is snug as can be, but I didn't remove it.

As far as the glycol "overflow" tube: on my trailer, the overflow tube that runs down to the Alde compartment and out through the plug is behind the cap. I can't see mine, but if I put my hand back there, I can feel the tube coming out of the tank and down.

ReenieG · December 2023

@manyman297 I believe mine is the same.

pthomas745 · January 5

For the 11 millionth time, I've read over all the glycol/corrosion/Alde change threads, and I'm ready to drain the trailer in the next couple of days and have a look at the convector ends that I can inspect. I will be using the ScottG suggestion about accessing the glycol loop just past the auto air bleeder valve. I will decide on taking the back bench/cupboards out to look at the rear convectors when I see what the passenger side looks like.

I intend to use a small 12V "air pump" (used for blowing up small inflatables) in the hose to help push the glycol up and out. And then use the "ScottG DIY Pump" to run some distilled water through.

In the corrosion thread, there is much discussion about "coating" the aluminum convector ends. There were several suggestions: conformal coating, heat shrink, electrical or silicone repair tape, and one set of comments included "grease", but provided no examples. Are any of these "better" to avoid the "attacks" by the trapped glycol? Will improved "bolted" hose clamps prevent any glycol intrusion, so things like electrical tape or silicone tape should be reasonably secure?

For the 11millionth time, I'm still astonished at the skills and knowledge sets across this long thread and this entire Forum group.

Edit: see the "Corrosion of the Alde Convectors thread for answers about the type of "seal" ideas.

https://tab-rv.vanillacommunity.com/discussion/13226/corrosion-of-alde-convectors/p22

DanWeitzel · January 5

pthomas745 said:

For the 11 millionth time, I've read over all the glycol/corrosion/Alde change threads, and I'm ready to drain the trailer in the next couple of days and have a look at the convector ends that I can inspect. I will be using the ScottG suggestion about accessing the glycol loop just past the auto air bleeder valve. I will decide on taking the back bench/cupboards out to look at the rear convectors when I see what the passenger side looks like.
I intend to use a small 12V "air pump" (used for blowing up small inflatables) in the hose to help push the glycol up and out. And then use the "ScottG DIY Pump" to run some distilled water through.
In the corrosion thread, there is much discussion about "coating" the aluminum convector ends. There were several suggestions: conformal coating, heat shrink, electrical or silicone repair tape, and one set of comments included "grease", but provided no examples. Are any of these "better" to avoid the "attacks" by the trapped glycol? Will improved "bolted" hose clamps prevent any glycol intrusion, so things like electrical tape or silicone tape should be reasonably secure?
For the 11millionth time, I'm still astonished at the skills and knowledge sets across this long thread and this entire Forum group.
Edit: see the "Corrosion of the Alde Convectors thread for answers about the type of "seal" ideas.
https://tab-rv.vanillacommunity.com/discussion/13226/corrosion-of-alde-convectors/p22

I did mine last summer using the shop vac method to remove the glycol and after cutting off the bad ends of the convector & cleaning them with sandpaper I covered the ends with heat shrink tubing. Then double clamped them using screw type worm gear clamps closest to the convector tube end and than reusing the factory clamps nearest the finned end of the rubber tube. No issues so far but haven't used the Alde much. since the repairs.

Image: https://us.v-cdn.net/5021717/uploads/editor/pn/9x6jah767xza.jpg

AnOldUR · January 5

I've seen different arguments, but constant and even tension make spring clamps the easy choice over gear clamps for me. Rubber fatigue caused by the repeated heating and cooling (expansion and contraction) cycles could cause gear clamp tension to be less than what you originally tightened to. This could increase the chance of leakage especially when the system is just starting up.

Horigan · January 6

That's a good point, though I suspect it's not much of an issue with a low pressure system like the Alde glycol loop. That does highlight why auto manufacturers use spring clamps in the cooling system that sees higher pressures.

pthomas745 · February 1

Update to my snail's pace glycol swap. I commented in the last month about ScottG's idea of forcing the glycol out of the trailer by disconnecting the hose at the point of the air bleeder valve. This connector holds the non-return valve. I pulled the plug on the glycol drain under the trailer, let it drain for a minute or so, and then pulled the hose holding the air bleeder/non return valve. Mistake #1: I pulled the hose from the end of the non return valve, and wound up spilling some glycol out of that hose. (I was saved by shop towels). At this point, there wasn't much draining from the glycol drain under the trailer. I attempted using a small air blower (the type you might use to inflate a small camping mattress) but there was not enough pressure to move any glycol. I tried the pump with the plugs recommended in the DIY glycol exchange file, but the plugs were not a good fit inside the hose. So.... I wrapped a clean towel around the end of the hose, and with two or three strong breaths blew the rest of the glycol around the system to the expansion tank, and it simply dropped out of the drain. I got 2.5 gallons of glycol into my bucket under the trailer. When I disconnected hoses from the convectors to inspect them for cleaning, there were only a few dribbles of glycol left in the system.

So: removing the glycol from the system at the point of the non-return valve is a perfectly good method. I'm assuming with a better "stopper" into the Alde hose, using some sort of air pump would be a possible if you don't like the taste of rubber hose. If I was smart enough to have taken the correct hose end off of the non return valve, I would not have spilled any glycol at all. The "stopper" may fit better into the non-return valve that would enable the pump to drive the glycol out.

I am also assuming I can partially refill the system with distilled water/glycol from this point. But, probably not completely. I'm guessing that after the expansion tank starts to fill, the water or glycol will begin to make its way to the air bleeder valve. Unless that can be plugged, it may be better to reconnect things and add water/glycol through the expansion tank.

Except for something to get the hose clamps off the drain plug and that one hose: an owner can get practically all the glycol out of the trailer with no tools if you don't mind using your own lungs. Of course, a pump or some other device with the proper air pressure would be a good thing!

The whole operation took less time than writing this comment did this morning.

Maple_Geek · February 10

I called a dealer near me today to try and get Rhomar glycol to do the job myself in a couple of months and he recommended dropping by to have it tested (I'm assuming he meant testing the pH of the glycol) and based on their experience witht he new glycol, it doesn't need to get swapped every 2 years despite what ALDE says. They are seeing more like a 4 years glycol swap based on their experience. Take it for what it's worth but I'm leaning that way at the moment.

pthomas745 · February 10

@Maple_Geek if you wind back through this thread and the corrosion thread, there does not seem to be any correlation between PH and corrosion, etc. At least, the evidence either way is simply not there.

AnOldUR · February 10

Maple_Geek said:

I called a dealer near me today ... it doesn't need to get swapped every 2 years despite what ALDE says. They are seeing more like a 4 years glycol swap based on their experience.

I would question "their experience". In my opinion, there hasn't been enough years of the Rhomar fluid being in use by nuCamp to establish the history to make this claim. If a auto service station told me I could go twice as far between oil changes than both the oil and auto manufacture recommendation, I'd find another place to get my oil changed. But that's just my opinion.

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