Want to practise : How to: Cooling system flush

[Max]

I WRITE MY QUESTIONS BELOW EACH QUESTION. ACTUALLY , I WANT TO SERVICE MY COOLANT SYSTEM TO CHANGE MY OLD COOLANT .THANKS VERY VERY MUCH!!!


1- Place a pan below the vehicle to catch the draining coolant.

2- Remove the reservoir cap.

ÞDOES THE RESERVOIR KEEP OPENING DURING THE FLASH?.

3- Run the engine until the thermostat opens. You can tell the thermostat is open when both radiator hoses are hot to the touch.

Þ CAN I CHANGE THE COOLANT WITH A COLD ENGINE ? I WILL FLUSH IT ANYWAY.

4- Turn off the engine.

5- Take off the little hose going from the top of the top of the radiator to the reservoir... take off the reservoir end only.
6- open the dran plug on the radiator to drain the coolant in it then put the plug back on

7- Turn on the engine and keep it revving at 2,000 RPM.

ÞCAN I USE NEUTRAL FOR MY AUTOMATIC TRANS .

8- Old coolant will come out of the little hose; replace draining coolant by pouring fresh water into the reservoir. Note that the water level in the reservoir should not go lower than the MIN mark.
9- Keep on doing this till the coolant coming out of the hose is perfectly clean.

10- Now replace fresh water with new coolant until the cooling system is filled with new coolant. You will now that the system is full with coolant when the hose drips clean coolant rather than fresh water (watch for the color of the fluid coming out of the hose).

ÞCAN I CANCEL THIS STEP ? (I JUST BROUGHT 3.5 LITRE CASTROL EXACTLY) IT MAY WASTE SOME COOLANT

11- Let the engine rev at the normal idling speed.

12- Put the hose back on the reservoir.

ÞSHOULD I STOP THE ENGINE ,THEN PUT THE HOSE BACK?.


13- Fill with coolant to the MAX mark.

ÞTHERE SHOULD BE ABOUT 3 LITRES WATER IN THE ENGINE .SO I CAN PUT 3.5 COOLANT CONCENTRATE INTO RESERVOIR NOW , THEN WAITING FOR PUT OTHER 0.5 WATER LATER . TO REACH 50:50 OF COOLANT AND WATER .


14- Put the reservoir cap back on.

ÞDOES THE RESERVOIR KEEP OPENING DURING THE FLASH?.


15- Keep the engine running till the cooling fans kick on then back off again.

16- Very carfully and i repeat very carfully open the reservoir cap to let out the air accumilated on top of the coolant. that air was traped in the system during the flush and was bled out buy the normal cooling system operation, you will notice that the more you open the cap the higher the coolan goes so you don't need to take off the cap, just unscrew it a little and keep an eye on the coolant level so that it doesn't spill then tighten it back on.

NOT SURE WHAT IT MEANS.

17- Repeat step 16 again after the cooling fans kick on then back off to conclud the bleeding process.

18- Fill with coolant if needed and check for leaks.

SO WITH HOT ENGINE ,THE LEVEL SHOULD NOT EXCEED THE "MAXIMUM "?

[MMamdouh]

I WRITE MY QUESTIONS BELOW EACH QUESTION. ACTUALLY , I WANT TO SERVICE MY COOLANT SYSTEM TO CHANGE MY OLD COOLANT .THANKS VERY VERY MUCH!!!

no problewms... maybe i will add this to the How to article as a FAQ or so

ÞDOES THE RESERVOIR KEEP OPENING DURING THE FLASH?.

yes... it is always open as you are going to be adding fresh water to the system to compansate for the water you are flushing through the return hose, remember this is an open loop circulation so you got to have a continous supply of water.

Þ CAN I CHANGE THE COOLANT WITH A COLD ENGINE ? I WILL FLUSH IT ANYWAY.

with the cold engine the termostate will be closed so most of the coolant will be traped in the engine block... you will only be able to flush very little portion of your coolant so it is an uneffective way to do the job.

ÞCAN I USE NEUTRAL FOR MY AUTOMATIC TRANS .

not really sure wht is the difference between using neutral or park in this setuation... the only reason for revving up the engine is to speed up the coolant flow and create enough flow to remove all the dirt or deposits in your cooling system, achive that on whatever tranny position you like as long as it doesn't hurt the tranny.

ÞCAN I CANCEL THIS STEP ? (I JUST BROUGHT 3.5 LITRE CASTROL EXACTLY) IT MAY WASTE SOME COOLANT

coolant waist is minimal here but if you still wanna save it all you can turn off the engine at this point and drain the radiator and put back the return hose you took off to flush the system and get an air compressor and pump air in the reservoir so that the air pushes the water out od the cooling system through the drain plug... you will still have some 2 liters of water at this point.

now turn on the engine and start filling all the coolant you got... according to my calculations (2L water + 3.5L coolant) you will have to add 1.5 liter of water to top your coolant... doing this step as per the how to article will put you at the same end result - you will end up with 3 liters of water traped in the system and you will add 3.5L of coolant then 0.5 L of water to top it off - but with much less hassle as you can see so i recommend that you do at as the article said unless you want to have a more concentrated coolant/water mix.

ÞSHOULD I STOP THE ENGINE ,THEN PUT THE HOSE BACK?.

you don't need to turn off the engine... the coolant is not that hot at this point and their is no high pressure flow to make the job a nightmare or so... it is very easy indeed.

ÞTHERE SHOULD BE ABOUT 3 LITRES WATER IN THE ENGINE .SO I CAN PUT 3.5 COOLANT CONCENTRATE INTO RESERVOIR NOW , THEN WAITING FOR PUT OTHER 0.5 WATER LATER . TO REACH 50:50 OF COOLANT AND WATER .

yes... according to both our calculations you will end up with a 50:50 mix.

ÞDOES THE RESERVOIR KEEP OPENING DURING THE FLASH?.

you already finished the "flush" part of the job so the reservoir cap is to be placed back on at this step.

NOT SURE WHAT IT MEANS.

some air found its way to the system during the flush... fortunatly the cooling system on our cars is self bleeding system so all you have to do is let the engine rev at idle till the cooling fans kick on then turn off... at this point all the draind air is accumilated at the reservoir. you CAREFULLY open the cap to let that air vent away from the reservoir an then repeat this cycle - idle till fans on then off ---> undo cap - once more to make sure their is no more air in the system.

SO WITH HOT ENGINE ,THE LEVEL SHOULD NOT EXCEED THE "MAXIMUM "?

yes, not sure how damaging it is to have the coolant system over filled but my coolant is some 1cm over filled just to make sure i got no leaks after the water pump and thermostate gasket job that i did... i recomment you stick with the MAX mark on the reservoir.

MMamdouh