OK, as we continue to work through a list of items for our mechanic to checkout, one item on the list has been the ability to get heat, and more importantly defrost, working up front.
Some background,
The floor in this bus had been lowered quite some time ago.
In order to accomplish this, several lines were cut and/or rerouted.
In discussing the heater with the previous owners, they believed that the loop going to the heater core was still intact and that I could just open the valve in the engine bay to allow coolant to pass to the front.
After checking out all of the cut lines, I saw coming out of the engine bay and into the backbay, I was really hesitant to open that valve for fear of making a huge mess if the lines were indeed left cut; so I left it closed until I could get someone with a better understanding (and a pit) to look at it with me.
Fast forward to today,
The lines were indeed cut, but were rerun.
Here's where it gets... Interesting.
Instead of running the makeup lines (the area that undoubtedly needed removal to accommodate the floor lowering) in new copper, whoever did the floor lowering used 1/2" (possibly 3/4") PEX instead. And this is old-school gen1-ish type pex, not the fancy sometimes color-coded, with higher tolerances, type pex.
Where it gets even more... Interesting, is the connection from the cut original copper to the new pex. It goes like this: Original Copper, to Rubber hose piece with hose clamp, to a grey PVC?? threaded fitting, to a threaded steel pipe piece, to a (quite rusty) threaded steel pipe reducer, to a threaded pex fitting, to PEX pipe. The other end comes out as pex back to the original copper (but not in the same as the former). It just seems to come out of there directly into the copper.
Ok, so now I'm a bit concerned.
What do you guys think? I realize this is "out of the box" types design so there's probably no set answer.
I think the pex will be able to handle the temps and certainly the pressure. From my research pex easily handles 180 degrees with tolerances (albeit non published) in the 200s.
I'm not certain what that grey threaded piece is. If it's pvc, then I think it's a problem since pvc is only rated to something like 140 degrees. If it's cpvc, then it's a bit better since that's rated to about 170-180 degrees.
That rusted steel piece is also concerning. Not sure if it's also rusting on the inside and could push rust into the coolant. Not to mention the possibility of it corroding to the point of failure (considering it's just attached to plastic).
I believe a lot of this can be decluttered if I could go more directly from the old copper to pex. The old copper looks like 1" (or more?) and I'm not sure such an animal exists (copper to pex fitting).
Since this whole assembly will be under 190-200 degrees, constantly, but under fairly low-ish pressure, what do you guys think?
I definitely think defrost is important, but so is not dumping 12 gallons of coolant into my bays, not to mention the rapid loss of coolant to the engine.
Your thoughts are greatly appreciated as always.
Thanks
George
Gray PVC is sch 80 it can handle a lot fwiw
Sounds like an area of future failure to me. Copper reducers are available so you should be able to find a 1" to 3/4" copper reducer to the 3/4 pex fitting. I would never leave something like that.
JMO I would not plumb any Pex into the engine system that would be asking for problems
Quote from: scanzel on March 10, 2016, 07:08:56 AMSounds like an area of future failure to me. Copper reducers are available so you should be able to find a 1" to 3/4" copper reducer to the 3/4 pex fitting. I would never leave something like that.
I agree with Clifford and Steve. PEX isn't good for coolant, heat, pressure, vibration in motor vehicle us. If you're going to join a replacement line to copper, make it the simplest and sturdiest connection possible (not the mess you have on there now). Something like that always fails at the worst possible time (rainy weather, in the dark, when you're in a hurry, miles from service assistance and spare parts/supplies ...). Don't take any unnecessary chances.
I would think about this for a while, and not leap to any conclusions. I have had copper lines fail on a vehicle due to vibration stress, I've never had Pex fail in the tube for any reason. I probably would not use Sharkbite type fittings - but then again DOT air lines use push to connect fittings... I have a nagging feeling that Pex is actually a really good choice for this, in contiguous runs well supported with good fittings and adaptors, if protected from cuts and abrasion (which you need to do for copper anyway, it is really quite susceptible to physical damage). I would redo the funky adaptor.
Brian
I tried Pex on my engine pre heat from the Webasto, maybe because of the heat in the engine compartment but it didn't work out for me cost me 200 bucks worth of antifreeze ???
I used PEX between my engine and AquaHot. Short lengths on either end. 12 years or more and no problems.
Something to consider regarding questions about any lines to and from your Aqua-Hot, Hydro-Hot or Webasto heating systems; you may want to call Lloyd DeGerald. He has been servicing these units for years and has fixed problems caused by folks who had made bad choices in plumbing and other things regarding these products. He can be reached at 501-258-8426 or lloyd.degerald@gmail.com.
He has seen it all so a call or email to him may save you a lot of money and headaches down the road. He services my Aqua-Hot system every year in Quartzsite and he has been a huge help in getting my system back in service after sitting unused for three years, which of course is the worst thing you can do for not only your Aqua-Hot but your bus in general. Lloyd says you should run your Aqua-Hot system at least once a month whether you use it or not. He sent us an article about servicing your unit which will run in an upcoming issue of BCM soon.
Check him out at http://lloyddegerald.com/locate-me-calendar. (http://lloyddegerald.com/locate-me-calendar.) Who knows, he may be coming to an event near you soon where he can look over your system and do a yearly tune-up on it so it will continue running for years.
George,
I don't think I would use PEX, but at this point I think it would be a major rebuild for you to replace it, especially if it is in the tunnel under the floor and the bus is finished. I would think changing out all the PEX connections to brass, using the solid crimp rings would be a start, and using flexible copper for all the easily accessible places.
I am more curious about which part of the floor is lowered? I have a 4905, and can't imagine the work to lower the rear part, unless the 4107 is substantially different than my 4905?
Steve Toomey
If all else fails, how about this? The defrost blower works. Why not remove the heater core and install a 12 volt electric heater in there and use that for the defrost?
Our Eagle has little electric heaters on the dash for defrost. They may not be pretty, but they aren't ugly and work great.
Don and Cary
Quote from: Cary and Don on March 10, 2016, 02:19:53 PM
If all else fails, how about this? The defrost blower works. Why not remove the heater core and install a 12 volt electric heater in there and use that for the defrost?
Our Eagle has little electric heaters on the dash for defrost. They may not be pretty, but they aren't ugly and work great.
Don and Cary
I'm glad you posted that Don, earlier today I was wondering what I was going to do about my defroster and you may have solved my problem. Thanks
Wes
FWIW; I believe schedule 40 PVC is grey, also. PVC is tough stuff. but I don't know about using it in this application.
There's a lot of room for improvement in many of the house systems, but I would have to look long and hard at re-engineering the vehicle systems. True, its only coolant; it won't make the wheels fall off; but it will shut you down! In your case, I would probably remove the improvisations and replace to OEM standards.
HTH
Ted.
Don't worry about the pex. It can handle the heat & pressure & vibration. I have pex from the engine compartment to the front. No problems in 15 years. The gray PVC is another story. It WILL fail. PVC will not hold up to that temp. Happy plumbing :)
I have infloor heat in my coach and it is pex . works great and is rated for 200 f . no problems at all and I installed it in 2005 . I used regular green auto anti freeze in the system to keep it simple . I have used the same pex in water solar systems and the temperature can get very hot ( above 300 f ) and have not had any problems .
I like pex and use it all the time on any plumbing projects
dave
I don't know where you guys live but Pex is failing here in Az in the attics of houses,then it could be from the great water we have in AZ it eats anything.I use it because it is cheap and easy to use with crimp clamps and brass fittings
George there is a fitting that will go from Copper pipe to Pex check H-Depot. Sharkbite I think has one also.
Remember when you open those valves if they have been closed for awhile you will mix new coolant with old that has been sitting for a long time or worse if there isn't any in the loop it will fill it and you will be about 7 Gallons short!...
Dave5Cs
Thanks for the info guys!
Yeah it's a real mess under there :)
I'm not really worried about the PEX. I've seen it deployed in radiant heating floor installation and those are usually hooked to a boiler installation and many use some form of anti freeze. Interesting about using it for solar heating as well!
As far as pressure and vibration, we have pex for our drinking water plumbing and absolutely love it. It's very tolerant of vibration (I often just bend/move it out of my way to work on stuff) and it's rated to 120psi. It's even taken being frozen more than once. No way copper would do that ;D. Plus as others have stated, rerunning that now would be a major undertaking.
That pvc has definitely got to go, along with all of those additional pieces.
I'm thinking of using a copper/pex reducer that would go directly into the pex. I really don't want to sweat copper to get this accomplished. The location is really difficult to get to and it's just under the wood sub floor. So I may retain the hose and hose clamp portion, attach a street (via hose and clamp) to pex fitting/reducer, and just get rid of the steel and pvc pieces.
I've seen a couple of votes for sharkbite fittings. I wonder if they'd hold up as well as the pex itself, hmm... Will have to check those out.
For now I think I'll close the valve in the engine compartment. Although the line is already full of fluid, if I'm not passing heated engine coolant through it, it should be ok, till I make the changes.
Don and Cary,
That's a really good idea. And I may give that some more cycles. From what I'm finding on line right now, however, the 12v heaters get terrible reviews and appear to be junk. I may fashion my own 12v heater coil core. I've got some kenthal wire and should be able to rig up a 7-10 amp heater that could ride up next to the existing core.
Steve,
The bus was lowered long before we got it. The bus lowering job looks like it was indeed quite a chore. And it was actually done quite well, from what I can tell. Everything is braced and supported well (I've spent much time with a flashlight walking around the area to make sure it's all holding as it should :) ). And it makes a huge difference in terms of precieved room in here. It was lowered about 4-5" starting from the back wall of the back bay, forward to the middle steps by the cockpit. It's all braced up on steel beams running down the side. I must admit, I don't really know what all is original and what is add-on. Someday I might see a "normal" 4107/4905 to compare :))
fwiw the weird joint may be connecting very old pex to more modern pex. Some of the very early pex type tubing did not work with regular fittings (compression or crimp) I have come across it a few times and had to save old adapters to connect it to more modern pex. Kind I came across was blue with a thin metal wall inside, but there may have been others, huge PITA to connect to.
I used Qest (gray PVC) on my bus from 1994. I've had one valve fail and one fitting crack. Otherwise it has been trouble free.
Now going to use Pex on the truck-mainly since Qest isn't made anymore. Pex is carried by Home Depot and Loews-so easy repair. Pex is used as plumbing on many houses since it is so easy to work with and is much cheaper than copper. There are very nice premade manifolds for Pex also. Good Luck, TomC
I would use a shark bite type fitting as temporary emergency repair only if the proper fitting is unavailable.
For permanent connection, use a proper crimp ring or quality ferrule & nut fitting. It is more work up front, but less chance of water leaks. Every water leak I have had was a sneaky one that wet more than I thought possible - took way more effort to repair the collateral damage than would have been required to use a better fitting the first time.
Best of luck with your project!
I found this document online a while back. It is a nice list of different chemicals and PEX's tolerance of them at different pressures and temps. I'm posting it here in case someone finds it handy. This primarily applies to this specific vendor's "PEX" but I believe it's likely applicable to all PEX in general (at least current generation).
https://www.mrpexsystems.com/pdf/technical_documents/MrPEX_Chemical%20Resistance%20Chart.pdf (https://www.mrpexsystems.com/pdf/technical_documents/MrPEX_Chemical%20Resistance%20Chart.pdf)
We have a Coachmen the wife purchased new in 1985 that has the grey poly pipe that stuff has never been a problem,I still see it new RV's of today.Pex needs better fitting the brass one are so thin some water like here in AZ eats the fitting up and the cheaper plastic fitting break you have to deal with problems on about anything you use IMO except the Stainless.Pex is cheap and easy to use but I would recommend buying sticks I redone a rental and Pex in roll is a bitch to work with I spent most of my time trying to uncoil the stuff the sticks worked so much better for me. lol I still have the coils I tied one end to the bus the other to my tractor and stretched it this July heat in AZ all was good I thought the next morning that stuff had coiled back to the original shape that is when I bought the sticks
You're cracking me up. Wife is wondering what's wrong with me. I completely understand the coiled pex drama haha! Same here. Stuff stays curved a long time lol
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I used the shark bite white pipe and Pex fittings and rings. Work well and no problems in 5 years. I had the grey PB and it would leak at the fittings. So replaced with the white pipe as the would go.
Dave
hi All, one of the best things I did with installation of my pex was eliminate 3/4s of the fittings, by using the newer corner slip on 90 degree bend external corner fittings, for every corner, less cuts, fittings and 2 less clamps, lvmci...
Tom, are you talking about the wall sweeps that nail to the studs
hi Clifford, these are 90degree corner bends, made out of steel or plastic, available at HD next to pex stuff, they fit over the pex, and then you snap in the other side making a 90 degree turn, as opposed to cutting the pex, inserting a elbow and clamping both sides, the pex tubing stays whole and still makes the corner, reducing the number of chances for a leak. I hope you and Sonja are well, tom...
These?
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fuploads.tapatalk-cdn.com%2F20160315%2F9cc69d3d6ad75a7b708cf2f7513c1e39.jpg&hash=1ae4622dc9ae2f8b7c5684718a0a7064d35f06ad)
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Those things are great and significantly reduce cuts/splices, assuming your're not turning a tight 90 degrees. They have quite a long bend radius to them. I'd also recommend the plastic ones over the metal. The metal ones seem to corrode/rust as the pipes condensate due to differing air and water temps/humidity (at least mine have).
That corner former is a neat idea!
Yea I been using the sweeps for several years around the house,but for me they take up to much area for the bus so I use the old 90's to make it more compact
Hu Scott, that's it, as Clifford said, it does use up more area, but I think the reduced splices is the benefit, LV doesn't really have issues with condensation, the plastic version also has a mounting hole, lvmci...