Is it possible to add coolant enhancer

[apole]

Hi there,

Having a coolant pipe changed this week and whilst I'm at it a new thermostat put in, along with fresh coolant. No overheating issues but as it's being drained down for the new pipe I may as well get it all done at the same time.

I've found an additive that looks interesting. Trouble is I have a feeling it won't arrive in time for the work this week.

The enhancer is just under 1 litre, I could suck out this amount from the header tank and add the enhancer but my question is will this then circulate around the engine or just stay in the header tank.

If that is the case, what is the best and least disruptive way to add this, I'd prefer not to have to do a full bleed, I can do it and have done before but to do it properly takes an hour.

Any advise would be great, not worth risking an overheat by cutting corners though !!

Andy

[haydn callow]

What you suggest could work but sucking 1lt out may bring the coolant level down below the level of the "top" small pipe that enters the tank on the L/H side...doing this is a big No !!No !! as air will enter.
I would suck out as much as you can without exposing that pipe....then add your 1lt of gubbins...if this brings the level above the full line...run the engine untill warm then wait for it to cool and suck out any excess untill the corect level is obtained..(Full line when cold)
No ..it will not stay in the tank...the coolant circulates through..

[apole]

Thanks Haydn,

Appreciate your help.

Regards

Andy

[haydn callow]

read the bumph on this stuff..whilst I'm pretty sure it will do no harm...I don't think I would be tempted...not cheap either.

[stilldesperate]

Haydn,

Could you get away with someone undoing the radiator bleed valve, and a second person adding the fluid to the header tank at the same time?

SD

[haydn callow]

Haydn,

Could you get away with someone undoing the radiator bleed valve, and a second person adding the fluid to the header tank at the same time?

SD

If you mean the drain tap...I suppose so but there is a risk it will drain a bit from the engine.....wouldn't risk it myself....what I say above will work.

[mikeonb4c]

Haydn,

Could you get away with someone undoing the radiator bleed valve, and a second person adding the fluid to the header tank at the same time?

SD

I think that would work well - can't imagine the precious fluid being added to the header tank barging ahead that much that it got wasted in the first issuings from the bleed valve. If it were me, I would (working on a cold engine):

1) Take level down as Haydn suggests.
2) add precious liquid to header tank, to the brim if need be.
3) Use bleed valve to lower header tank level so Full mark not exceeded when cold and before engine is run up to temp

But I would think any of the above methods should get a good result - I just hate to think of header level rising and dumping any precious liquid through overflow before its got mixed in (but not being a hardened cooling system expert I don't know if that could happen...)

[haydn callow]

The danger with allowing coolant to escape via the radiator Drain tap (no bleed valve on a Bongo Rad) would be that coolant could also drain back from the bottom hose leaving said hose full of air...I would not risk this as the first time the stat opened any air left in there would rise to the cylinder head.

[mikeonb4c]

The danger with allowing coolant to escape via the radiator Drain tap (no bleed valve on a Bongo Rad) would be that coolant could also drain back from the bottom hose leaving said hose full of air...I would not risk this as the first time the stat opened any air left in there would rise to the cylinder head.

Yup, I appreciate there is no bleed valve, just a drain tap - for simplicity of reference I repeated the term that SD used. Its because it is a drain tap at the lowest point in the system (I suspect) and operating on gravity feed in a hydraulic system that I'm tring to understand how any air could get introduced into the bottom hose - sounds odd to me. Can you shed some light?

[haydn callow]

As the Expansion cap would have to be off during this operation (no longer a sealed system), I would guess that coolant could drain back from the bottom of the rad and also the Bottom Hose.. Why risk it when there is no need.??

[rita]

Hi,if you set your bleed pipe at the same level of the coolant in you header tank,then pour in the additive this will displace the exact amount of coolant.

[mikeonb4c]

As the Expansion cap would have to be off during this operation (no longer a sealed system), I would guess that coolant could drain back from the bottom of the rad and also the Bottom Hose.. Why risk it when there is no need.??

I think that is unlikely. Its much the same as a bucket with a hole (drain tap) and no lid (expansion cap). Air don't enter via the leak. UNLESS of course it has a sealed lid (expansion cap left on). Then air will try to get in to replace what would otherwise be a vacuum at the top of the sealed bucket. Whethere it manages it depends on size of drain hole, viscosity of coolant, and any mechanical agitation that dynamically increases the vacuum and induces air entry. But as the expansion cap has to be off in order to pour the stuff in, then its academic.

So no risk, but possible need IF expansion causes precious fluid to be pushed out the overflow before it has got mixed into the system...which is what we were pondering on initially

[mikeonb4c]

Hi,if you set your bleed pipe at the same level of the coolant in you header tank,then pour in the additive this will displace the exact amount of coolant.

That ought to work. A new application/variation for the Allans/Haydn principle for bleeding

[haydn callow]

Mike..I'm not suggesting that air will get in via the leak (drain tap) what I am suggesting is that whilst coolant is draining from the expansion tank via the radiator it will also "possibly" drain some coolant from the bottom hose via the bottom radiator tank.......All I am trying to put across is that this is a possibility.....and is there any point in risking it ???? on the other hand.....dropping some out of the expansion tank by , 1..sucking some out...or 2...releasing the radiator cap (not removing it) and allowing just enough coolant to escape so the small tank pipes are not exposed is a safer way of approaching the problem.....That is what I would do if I was trying to add some enhancer or antifreeze.
Using the bleed tube may well work...but why go to that trouble and ..again why risk dropping the bleed tube or whatever....(only one pair of hands)....


If that is the case, what is the best and least disruptive way to add this, I'd prefer not to have to do a full bleed,

That is my advice to the original question.......nuff said by me....!!!!

[mikeonb4c]

Mike..I'm not suggesting that air will get in via the leak (drain tap) what I am suggesting is that whilst coolant is draining from the expansion tank via the radiator it will also "possibly" drain some coolant from the bottom hose via the bottom radiator tank.......All I am trying to put across is that this is a possibility.....and is there any point in risking it ???? on the other hand.....dropping some out of the expansion tank by , 1..sucking some out...or 2...releasing the radiator cap (not removing it) and allowing just enough coolant to escape so the small tank pipes are not exposed is a safer way of approaching the problem.....That is what I would do if I was trying to add some enhancer or antifreeze.
Using the bleed tube may well work...but why go to that trouble and ..again why risk dropping the bleed tube or whatever....(only one pair of hands)....


If that is the case, what is the best and least disruptive way to add this, I'd prefer not to have to do a full bleed,

That is my advice to the original question.......nuff said by me....!!!!

Gotcha

Well I guess he's not spoiled for options on this one

I'll be v. interested to hear if the precious liquid makes a noticeable difference - might try some myself (for the Bongo ) if so