Whats this

[Garyowens]

Can anybody tell me what this bottle is for?,the fluid in mine is getting low is it for the a/c as it says refrigerent?

http://i287.photobucket.com/albums/l.../rb20det-1.jpg

thanks guys

Gary

[Trev]

That looks like the coolent bottle.

[Garyowens]

As in engine coolant?Is it a 50/50 mix or 100% coolant.Is the coolant not in the rad?

Gary

[Trev]

Yes, engine coolant, just top up if low.

Coolent is in the rad with water, can't remember the exact mix but it's not 100% coolent!

[iceager]

its an expansion tank... When the cooling system gets over the 0,9bar the radiator cap opens and shoots the overflow of coolant in that tank.

Coolant is diffrent, some are 50/50 others are pure coolant, like in Japan, but its a diffrent fluid as it dont protects for cold weather. depends on where you live i guess.

Castrol anti freeze fluid is 50/50 and then protects to -38 celcius and its anti corrosion too.

[Garyowens]

So i dont fill it up then,i'll leave it as is as it is nearly empty?

[Trev]

Originally Posted by Garyowens

So i dont fill it up then,i'll leave it as is as it is nearly empty?

It should be reading on/just under the FULL mark.

[Garyowens]

Sorry for all the questions but if the coolant is in the rad with the water then why do i need a seperate coolant?Is it not an expansion tanks as iceager says.

Thanks
Gary

[Gambit]

Coolant is in the rad, but as it heats up it expands. The expansion tank is where the expanded amount of fluid is forced into. Should be at the max mark when the engines up to running temp.

[beaumackenzie]

as above when the engine gets hot, the coolant expands, under pressure hot water will stay as HO2, however once the pressure of the hot water in the radiator rises above .9 bar (which the radiator cap is used for) it releases that excess pressure along the rubber hose from the neck of the radiator into the bottle with the yellow screw on lid, on the side of the bottle there is a low and high mark, the fluid in the bottle should be between these two lines all the time, but not below or above either of them ,

the purpose of this system is to stop the boiling water from converting into steam(when the oxegen particle seperates from the 2 hydrogen molecules)

if it wasnt under pressure the water would evaporate and the coolant level in the engines system would slow decrease to the point it would air lock the head cracking it.

the purpose of the coolant in the bottle is similar to an airlock, it works to trap the escaping steam from the radiator and cools it back down as it passes through the water in the bottle, condensing it back into water.

when you stop driving the car and the engine cools down the water in the engine and radiator contracts as the exited particles of water stop moving so fast and stay closer together. as it contracts it sucks water back into the radiator maintaining the level of the water coolant without sucking in air.

similar to boiling water freezing water has similar issues, as water freezes it expands as it traps the oxegen molecules in the hydrogen(hydrogen will not contract(cant compress water) so the oxgen molecules expand as it freezes making ice 10% lighter then liquid water, (this is the bouyancey that makes icebergs float with 90 % of there mass still submerged)

obviously ice cant float in the engine block as it is surounded by steel and aluminium and this is why engine blocks have frost plugs, when the water freezes it expands pressurizing the system and pops the frost plugs to release the pressure(otherwise it would crack the water jacket of the engine)

the purpose of the coolant mixed in the water is to lower the freezing tempurature of the water(as above down to 30 degrees below o'Celcius.)

it is also the purpose of the coolant to raise the boiling point of the water (upto 130 degress celcius) to stop the water evaporating when the engine is hot.....

essentialy the purpose of the coolant is to expand the range of temperature of the water before it's start's altering its molecular structure.

im no einstien but thats basic chemistry that ya learn at school.