Coolant System Green Goo

[travelite]

Seems I have a green film inside my coolant system. Three years ago I had Prevost replace the coolant with ELC. I also had them renew the filter. Just to make sure I'm running as close to pure ELC as is reasonable this weekend I flushed many gallons of DD PowerCool ELC thru the system. The last thing I did was replace the coolant filter. When I took the old filter off and held it upside down some deposit fell out. When I cut the old filter apart I found a significant coating of green goo on the paper element to the point where the filter was clogged. I removed the sight glass from the deaeration tank and ran my finger along the inside of the tank, a green film transfered. I have a multi-thousand mile trip planned for this summer and I'm reluctant to run a caustic alkaline cleaner such as Fleetguard Restore through the system. I'm worried that this type of cleaner may cause problems during the trip; i.e., from loosening debris to eating away at seals and hoses. The manual has a lengthy description on what to do if coolant system contamination occurs resulting in engine overheating. Their remedy includes a fairly involved process of backflushing the radiators and the engine. In fact, any coolant system flush includes the recommendation of removing the transmission cooler for inspection, which I didn't do, and which I may do before the trip. My engine doesn't overheat. It runs beautifully just the way I would expect. On a 90 deg F day the coolant temperature runs around 190 to 195 deg F as does the oil temperature. The transmission temperature settles in around 205 to 210 degrees with occasional retarder use. Heavy retarder use on 6% grades sees transmission temps climb steadily to 230 where it stays for a duration as the fan kicks in full speed - the rate of temp climb from that point on is slower. Pulling long 6% grades out west in the summer sees the water temps climb to 200 to 205 deg F. I don't see any evidence of overheating, so according to the manual there are no grounds for backflushing. Any thoughts on what you would do knowing that a trip is planned in the near future?

[Gil_J]

I hope the filter was a blank and not the standard SCA charged filter. If it was I'm pretty sure your ELC no longer ELC.

[travelite]

The filter I just put on is a blank: Wix 24070. When Prevost (Nashville) changed the fluid 3 years ago I asked for a blank filter. They said the didn't have any. I thought that meant they wouldn't change it. Checking my receipt I see they charged me for a NalCool 3000 filter. Goes to show you need to verify everything they do. If I had seen it at the time I would have isolated the filter and had them reverse the charge. This was three years and 14,000 miles ago. All the above led me to my adventure thus weekend of pumping 45 gallons if fresh diluted DD PowerCool ELC through the system. I now have pure ELC and a blank filter, but definitely a film in the system. I'm going to pull the transmission cooler but I may wait till after the trip.

[Gil_J]

Oh no! Given most Prevost service centers have all but eliminated the old non ELC coolant from their parts department I'm surprised they had the charged filter.

[travelite]

We know that OAT coolants can be mixed with standard coolants but we lose the benefits that OATs provide. What we don't want to use or mix in a heavy duty diesel is an automotive style coolant because of their high silicate and phosphate content. I'm looking for pics but I think my coolant issues existed when I bought the bus. IIRC, my site glass on the overflow tank always had a film on it. It was always a little dirty. The silica gelation (green goo) can be caused by a ton of things from mixing with automotive coolants, to running at high temps, to adding too much SCA's, to not having enough SCA, to simply being plane old and used up conventional coolant. This is why conventional coolants are such a pain in the ass! This weekend I flushed my system with DD PowerCool ELC which is Old World Industries Final Charge. I installed a new blank filter and I drove my normal 60 mile warm up trip. I then removed the filter and cut it apart. It was spotlessly clean. So at least I know I don't have any chunks of green goo floating around and I know I don't have any other types of precipitate floating around. Judging by how it runs I think I'm fine, but I may do a little disassembly to verify. When I return from our trip I'm going to remove the transmission cooler and take it apart. Turns out it has an outer shell and an inner removable tube assembly. There's a handful of o-rings that seal one fluid from the other. These seals should be replaced anyway. (Remember what I said about Fleetguard Restore attacking seals)? The manual says to replace these seals whenever the coolant is drained, which would be every two years if you're using conventional coolant. Those of us with retarders are all overdue for seal replacement inside our transmission coolers. That's one part, among many, of the "Zeroing-Out" philosophy that everyone misses. :)

Has anyone here ever taken a Prevost transmission cooler apart?

[Joe Camper]

Yes I pulled a cooler on a 96 Marathon that was in a flood and underwater and the level was above that cooler for x amount of time. Prevo changed them over the years. This was located down low between the rad and the engine, a cylinder about a 18in long 5 or 6in in diamiter with end caps that unbolted. It had corroded to the point it was dripping and apon inspection on the bus I was able to poke a screwdriver right throught the rusty bit. We replaced it. I took it apart to see inside. The bottom half was plugged solid with rust.

[travelite]

Thanks Joe,

I was wondering how easily they go back together. The maintenance manual says it's best to use a press when seating the tube assembly into the outer housing. It's only pushing against seals but they're concerned about the entire assembly remaining square during the process. All in all, the whole disassembly/assembly process with new seals looks pretty simple. The only special tool is a press.

[Joe Camper]

By the way Dave. On Sept 24 and 25 there is vintage auto racing at Virginia international Raceway. That's very close to u.

I'll be in Thomasville with Mr Jack for a good week beforehand maybe longer messing with his camper and mine. Then I get to be part of the pit crew at the track.

Your kids would love the race weekend. It would be a great weekend for everybody for that matter. Camping spots abound. Very cool event.

It has become an annual event on my schedule.

This would be a great mini rally too.

[travelite]

Very cool Joe. I'll put it on my calendar. We used to attend all the vintage events at Laguna Seca when we lived in California. We started having kids and I kind of fell out of it. I have an old Triumph in my garage I restored, a TR250. I've owned it for 30 years. I'm the second owner. Years ago I thought about racing it but I bought a 911 and tore up the track with it instead. Wish I still had the 911.

[Joe Camper]

The track uses a Paul Newman quote in their stuff.

He said, If God had a road course it would be VIR.
14441

14442

The only thing I did not see there was brass cars, but everything else under the sun and I'm talking EVERYTHING.

Sorry for the thread creep.

It will be interesting to see if u have any sediment in your cooler.

If that superviser guy Gill was more proactive with the threads he could organize all our creep for us.

[travelite]

Yum, yum. :) I'm embarrassed to say I've never been to VIR. Looks like I'll have to fix that! :)

I need to apologize to Prevost (Nashville). I think they did the right thing by screwing on a NalCool 3000 needs release filter. The attached Detroit Diesel document says:

From the attached DD document: "Cooling Requirements for Engine Cooling Systems":

"These types of coolants (OATs) should not be mixed with Standard Life Coolants. If an ELC antifreeze coolant and SLC antifreeze coolants are mixed, damage may not result, but the long-life advantages of the ELC antifreeze coolant will be lost. In this event, the coolant should be re-inhibited with OAT inhibitors and confirmed by analysis or else it must be maintained as an SLC antifreeze coolant."

So Prevost did the right thing by screwing on a NalCool 3000 needs release filter after partially filling my system with ELC (OAT). If you have a mixture then one option, as the above spells out, is to treat and maintain the fluid as a standard non-organic ethylene glycol fluid. The other is to retreat with new OAT inhibitors but who can do that and how is it done?

[Donnie Myers]

Very cool Joe. I'll put it on my calendar. We used to attend all the vintage events at Laguna Seca when we lived in California. We started having kids and I kind of fell out of it. I have an old Triumph in my garage I restored, a TR250. I've owned it for 30 years. I'm the second owner. Years ago I thought about racing it but I bought a 911 and tore up the track with it instead. Wish I still had the 911.
My 911 might be for sale as I never get to drive now that I have custody of my Grandkids:(

[Gil_J]

Donnie, I have a great solution for your Porsche. Hire me and make that my company car.

[Joe Camper]

Not a bad daily driver.

14447

Look at that Dave there it is. And if u get it u can put it on the track against the likes of this!!

Too much fun.

Do u really want to sell that Donny?

[travelite]

It's beautiful Donnie! Trouble is, I got kids too. Four of 'em and I already have too many two seaters that I don't drive! (Even though the Porsche has somewhat of an excuse for a back seat)! GLWTS.

Obligatory on-topic content: Right now I'm wishing my bus was air cooled! :)

[Donnie Myers]

Not a bad daily driver.

14447

Look at that Dave there it is. And if u get it u can put it on the track against the likes of this!!

Too much fun.

Do u really want to sell that Donny? Not really, but it sits in an air conditioned car hauler and I rarely drive it. I spent tons of money on her! K-16 billet turbos, 4.5" coolers, injectors, built tranny to hold 1000 HP, full new factory Savanah Beige interior with Recaro Sportster racing seats, custom steering wheel, Billstein PSS10 coil overs, my front differential works and works well! It is very fast! I have pulled off several New C7 Zo6's as well as cocky Hellcats! People give me hell because it's automatic and they don't like 996 headlights! But I like it..A LOT..lol

Sorry about hijacking your thread David! At least I gave you some info over the phone lol

[Gil_J]

David,

This is probably as close as you'll get to air cooled in a Prevost.

https://www.prevostcar.com/news-and-media/media-center/news/electrifying-future-prevost

[Donnie Myers]

Not a bad daily driver.

14447

Look at that Dave there it is. And if u get it u can put it on the track against the likes of this!!

Too much fun.

Do u really want to sell that Donny? I forgot to mention...I'll play lol

[travelite]

I had a coolant analysis done on the coolant I dumped from my system. This is the coolant that's been in there for 3 years and 15000 miles. If I was smart I would have done a Level_2 analysis. What I got is a Level_1 which doesn't provide much, but what it does provide is very encouraging. Of what they checked, everything looks great. It's a little hard to read; zoom way in. In short, there are no precipitates, the pH is spot on, the conductivity is correct indicating no abnormal corrosion, and the nitrites are perfect. The analysis came back perfectly normal which is reassuring and enforces my decision not to do a caustic alkaline rinse.