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Coolant recovery tanks mounting height

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bobct

Advanced Contributor
"On my Trojan 10m, the recover

"On my Trojan 10m, the recovery tanks were mounted by brackets using one of the elbow bolts as the connection point.

I can't find the same style tank or bracket so I got two new tanks which mount differently.

Originally, the tanks hung on the inboard side of each engine and it was easy to get your feet tangled up in them if you were doing work in the area.

I would like to mount them behind the H/E (will need to fabricate something) so they're out of the way. In this case, they would be a little higher than the heat exhangers by 8-10".

I assume the pressurized coolant coming FROM the h/e will flow upward w/o a problem but wanted to check with you guys.

In the original setup, the tanks were lower than the h/e....


Bob"
 
"Bob; I think having the tank

"Bob; I think having the tanks higher than the HE will cause overflow at the HE when/if the cap is removed. BUT, I don't think in operation, it otherwise will matter.
Have you run these engines without recover tanks? I have never used tanks, and rather wonder the advantages. I can't visually inspect the coolant level thru a clear tank, and I need to leave an inch or two of air space in the HE. Not a big deal, though."
 
"Dave is correct...... a reco

"Dave is correct...... a recovery tank being at a higher elevation will/may cause an issue when opening up the pressure cap on the H/E when the engines are cold!
Best, IMO, to keep level or below!

Also, the pressure cap must be the correct style for recovery to occur!
Vacuum from cooling draws any expanded coolant back into the H/E..... Hence "Recovery"!
If an incorrect cap is used, you may not get a seal in order to create the vacuum.... and the cap must allow for reverse flow."
 
"Bob:

Dave's observatio

"Bob:

Dave's observations are spot on. They make a set of "hose clamping pliers" that are ideal for pinching the interconnect hose if you need to remove the cap. The coolant flowing into the bottle has very little pressure behind it, normally, and will "go uphill" w/o any issue.

Dave:

I ran for years w/o them and never had an issue then. The HX kits came with them so they were installed. Biggest benefit is "faster" maintenance time. A quick lift of the little hatch and an eyeball on two tanks vs moving the engine boxes and removing the pressure cap. If you are diligent, you can detect those little drips before they become bigger leaks, by monitoring the tank."
 
I did not know there was a spe

I did not know there was a special tool to use for that tiny clamp on the filler neck of the EX. If you knew how many times I have sliced my pinky on that tail of the clamp!

I have one for the 1960's Harleys where it is an over sized ring that gets crimpled so the final result is a circle with a t-handle looking shape to it.

Dumb ! Should have use it BUT...there is also NO space above the EX on out boat
 
"[b]The coolant flowing into t

"The coolant flowing into the bottle has very little pressure behind it, normally, <u>and will "go uphill" w/o any issue.</u>

Agreed! It certainly will!
However, the elevation is actually best if kept at/near the top level of the Heat Exchanger.
It's the siphon that would cause the coolant to flow from an open H/E pressure cap port when a recover tank elevation is higher than the H/E.
The coolant would puke when the cap is removed.

Too low, and the siphon can cause the recovery line to become partially void of coolant when the pressure cap is removed.

To me, it would appear that there is a little bit of science to this if we want the system to work as designed!
I.E., take care of coolant expansion, yet close to full recovery when cold! "
 
"If the degas bottle is above

"If the degas bottle is above the HX and the HX cap is removed, its not a syphon pushing it out the HX neck...more like atmospheric pressure.

Concur with your recommendation with this clarifier - most manufacturer's recommend the filler opening of the bottle and the HX filler neck be at the same elevation.

Al: I was referring to a set of clamping pliers designed just for pinching off hoses, not the clamps. see here:
http://www.kd-tools.com/145.htm
I removed those finger cutting clamps and replaced them with tie-wraps - much more compatible with my hands."
 
"Boy you guys really know how

"Boy you guys really know how kill my good ideas


So, it sounds like it would be ok so long as I used hose pliers (which I own and have an extra I can leave on the boat) whenever I remove the cap.

If I move them behind the HX's, I think I can get them close to level, maybe slightly higher.

In the factory setup, they were quite a bit lower, maybe 10" or so. As I mentioned, they're constantly getting kicked in this location.

Plus, I can't find the original bottles or brackets so that kind of forced my hand to do something else.

Dave, if I hadn't already bought them I probably would consider running without any.

Bob"
 
"Bob:

The good part is if t

"Bob:

The good part is if the bottle is full, there's little reason to have to remove the cap.

the fill caps on bottles are at least 12" under the HX filler neck. no problems over the years. only caveat to add is they are the Merc retrofit kits that I bought when I had one OEM HX fail."
 
"Mark, I think I see how you a

"Mark, I think I see how you are looking at this.
If the recovery bottle is set up w/ a bottom feed only, this would be the atmospheric pressure you mention.
If top feed w/ a dip tube, then it would be a siphon back to the H/E fill neck and over-spill! (the latter being what I was refering to!)

Either way, I'm still thinking that the coolant levels should be close to one another.


"The good part is if the bottle is full, there's little reason to have to remove the cap."

Yes! Agreed!"
 
"Mark, Regarding clamps....Hav

"Mark, Regarding clamps....Have you seen the CLAMPTITE tool...It uses stainless wire to wrap around hoses and then you use the tool to twist the wire into (what looks like ) a GM wire hose clamp? Saw on on ShipShape last week...3 different sizes available...Any thoughts?"
 
"No, Al, haven't seen it.

"No, Al, haven't seen it. Will search when time permits. Initial thought is NOT to use it on fuel lines, other apps may be ok."
 
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