Just Commodores Forum Community

It takes just a moment to join our fantastic community

Register

How To Flush A V6 Cooling System

Discussion in 'Holden Commodore How-To's' started by ChRiDDa, Mar 17, 2006.

  1. ChRiDDa

    ChRiDDa Active Member

    Messages:
    704
    Likes Received:
    104
    Trophy Points:
    43
    Joined:
    Jan 25, 2004
    Location:
    N/A
    Members Ride:
    VE SS-Z Sportwagon
    This is a step by step guide provided to assist those who are wishing to change the coolant in their V6.
    This was performed by myself on a 1997 VS V6 for those of you wanting to know. I am not a mechanic, and I will not be responsible for anything that happens if you decide to perform this task yourself. If your in doubt, have it completed by a professional. I will be happy to answer any queries any of you may have

    Products for the Job
    Above is a picture of the parts needed to complete the job. They include 5L of Castrol 350 Anti-Freeze, Anti-Boil Coolant, Nulon Radiator Flush & Clean, a Tridon thermostat gasket, a Dayco 91c Thermostat and a CPC 135kPa radiator cap.

    Tools for the Job

    Basic hand tools are nescessary to complete this job successfuly. Above is a picture of the tools that I have for the job. They include a set of screwdrivers, both flat bladed and phillips head. I also have a radiator clamp removal tool, which is ideal for those hard to reach clamps, attatched on the end, a 7mm 1/4" socket. A good quality socket set is also ideal. Pictured below is a Kincrome 1/4" and 3/8" socket set.

    Step 0 - Remove the engine cover

    Step 0 - Add Flush & Clean to radiator

    Remove the engine cover. This is secured by 4x10mm bolts.
    First of all, Undo the top radiator hose clamp, gently twisting the hose and remove it from the top radiator snout. Hold the hose upright and pour the entire contents of the radiator flush & clean in.
    The level in the hose will drop, so just be patient and slowly pour the contents of the bottle in. Once the contents have been poured in, place the top hose back onto the radiator and securely tighten the clamp. This should be performed when the car is cold to prevent burning yourself. Set the heater control to the HOT position and leave them there for the duration of the time it takes you to finish the task. Start and run the engine for around 20 minutes to allow the flush and clean to fully circulate through your cooling system, including your heater core.
    This product is designed to remove the rust, scale and sludge from your cooling system. I am using this product, as I know how the car has been looked after in the past. Sometimes it can be a double edged sword,
    as it can remove build-up that has actually been blocking small leaks within the cooling system. This is your choice, whether you decide to use this product or not.

    Once the product has been circulating through your engine for no less than 20 minutes, park the car and let it cool down for around 45-60 minutes. This prevents damaging the engine from putting cool water through the system and also minimises the chance of burning yourself! There are a number of ways to flush the engine.. I chose the most involved way, as I like to do the job properly the first time.

    Step 1 - Undo radiator cap

    Step 1 - Undo bottom radiator hose clamp
    Remove the radiator cap. Remove the clamp securing the bottom radiator hose, enough so that you can slide the clamp down the hose without damaging it. Now the hose will have bonded to the radiator snout, so grab it and gently twist it from side to side to break the seal. When this is done, pull the hose back towards the engine. The coolant will flow, so make sure you dont have your feet in the way!!!

    Step 2 - Undo top radiator hose clamp
    Step 2 - Reverse flush radiator

    Remove the clamp securing the top radiator hose. Remove the top radiator hose from the snout, exactly how was done when pouring the flush & clean in. Leave the hose hanging out of the way. Replace the radiator cap securely. Grab a garden hose *making sure its clean* and turn it on. Place it in the bottom outlet and block it off with your hand as best you can. Water will start to flow from the top hose outlet, continue to this process until the water flowing from the top radiator outlet is nice and clean. This process is known as reverse flushing the radiator

    Step 3 - Undo heater hose clamp
    Step 3 - Flush heater core

    Step 3 - Desired result

    Remove the bigger of the 2 heater hoses on the RHS of the engine (sitting from drivers seat). Replace the bottom and the top radiator hoses, but don't worry about securing them. Remove the radiator cap, and once again, place the garden hose in the filler neck. The radiator will fill up, then begin to circulate through the heater core. The heater controls MUST be set to HOT in order for this to work correctly! You will see all of the sludge come out of the side of the engine. Continue with this until the water flowing from the block is clear. Cover the block outlet with your hand. This will start water flowing from the hose you disconnected. Continue this procedure until the water starts to flow clear! You can do these steps as many times as you like, or untill your happy with the clarity of the water flowing out

    Step 4 - Remove engine belt

    Step 4 - Remove top clamp and hose
    Step 4 - Remove thermostat housing

    Step 4 - Thermostat housing removed

    Undo the engine belt using a 15mm spanner. Press down hard on the spanner until you can easily remove the belt
    Undo the hose clamp securing the top radiator hose to the thermostat housing. There are 2x13mm bolts that secure the thermostat housing to the inlet manifold. Remove these and then remove the housing from the engine. You now have a clear view of the thermostat. Remove this, noting the position it was installed. As you can see from the picture, the gasket is well and truely bonded to the housing. You will need a razor blade and some sand paper (used 150 wet and dry) to remove this. I also used a small amount of throttle body cleaner on a rag to get it looking nice and spiffy! This also needs to be done to the inlet manifold. ALL TRACES OF THE OLD GASKET MUST BE REMOVED!!! I placed an old hanky in the entrance to prevent the entry of old gasket/metal filings.

    Thermostat housing with old gasket

    Clean thermostat housing

    Old thermostat and housing

    Cleaning Thermostat housing - wire brush

    Cleaning Thermostat housing - razor blade

    Cleaning Thermostat housing - wet/dry sand paper


    Step 5
    Place the thermostat housing back, securing it with the 2 bolts. No need to worry about installing the thermostat or tightening the bolts properly for the time being, as this will be done later! Place the top radiator hose back over the housing, and remove the bottom radiator hose from the radiator snout. Turn the garden hose on and place it in the top hose. I started the engine to allow the water pump to circulate the water. This is your choice as to whether or not you decide to do this. I only had the motor running for a minute. The water will begin to flow out from the bottom hose.

    Step 6

    Remove the overflow bottle from the vehicle. It is only held in by 2 phillips head screws. Fill this 3/4 with water and shake violently to dislodge all the sludge contained within. Continue this process until your happy with the cleanliness of the bottle. Once complete, replace back into vehicle.

    Step 7

    Now that all is clean, you can begin to replace everything. Place the thermostat gasket on the housing (one side of the gasket will be adhesive)
    Place the thermostat into the inlet manifold, ensuring that it is installed the correct way. Replace the housing, place the bolts back in and tighten to specific torque. I don't have access to a torque wrench, so I just ensured they were "tight"

    Step 8

    Replace the heater hose and secure it with the clamp. If the clamp is dodgy, replace it. Replace the bottom hose and secure it, once again, same procedure applies. Replace the top hose onto the radiator snout. Leave the top hose disconnected from the thermostat housing, as this will allow the trapped air to be bled out.

    Step 9

    Pour the entire contents of the 5L of coolant into the radiator, taking care not to spill any! If you do, wash it off immediately!

    Step 10

    Fill the radiator overflow bottle 25mm over Max, with a little coolant and water. Leave the radiator cap off and start the engine, as the coolant level drops, continue to top it up. Once the level will not go down anymore, replace the cap and observe the thermostat housing. Once coolant starts to flow from the housing, turn the car off and replace the top hose and secure it with the clamp. Start the car once more and observe the temperate gauge. Once it begins to rise, feel the top radiator hose and make sure its getting hot and building up pressure.

    Step 11

    Wash down the area where you have been working to remove all traces of coolant to ensure your paint doesn't get damaged!

    Step 12

    Take it for a test drive, ensure the temperature rises and falls on the gauge. Stop about 10 minutes after driving, pop the bonnet and ensure there is no leaks!

    Step 13

    Done, stop and admire the fruits of your labour!
     
    Last edited: Jun 17, 2006
    pow3rslave, 90VN55 and sixshooter like this.
  2. ssute57l

    ssute57l New Member

    Messages:
    223
    Likes Received:
    3
    Trophy Points:
    0
    Joined:
    Feb 11, 2006
    Members Ride:
    VYII SS UTE
    you should also bleed this system!
     
  3. ChRiDDa

    ChRiDDa Active Member

    Messages:
    704
    Likes Received:
    104
    Trophy Points:
    43
    Joined:
    Jan 25, 2004
    Location:
    N/A
    Members Ride:
    VE SS-Z Sportwagon
    "Leave the top hose disconnected from the thermostat housing, as this will allow the trapped air to be bleed out"

    Might wanna pay closer attention next time...
     
  4. steen

    steen New Member

    Messages:
    18
    Likes Received:
    0
    Trophy Points:
    0
    Joined:
    Dec 7, 2005
    Members Ride:
    VZ
    This is a damn timely guide & pics, ChRiDDa. I want to do this with my old VR Acclaim. I was told the adjustment screw on top of the thermostat housing is for bleeding air out. Not required?
     
  5. ChRiDDa

    ChRiDDa Active Member

    Messages:
    704
    Likes Received:
    104
    Trophy Points:
    43
    Joined:
    Jan 25, 2004
    Location:
    N/A
    Members Ride:
    VE SS-Z Sportwagon
    thats definately what its there for, but i chose not to remove it.. left the top hose off insted, but its up to you which way you do it, really doesnt matter :)
     
  6. ssute57l

    ssute57l New Member

    Messages:
    223
    Likes Received:
    3
    Trophy Points:
    0
    Joined:
    Feb 11, 2006
    Members Ride:
    VYII SS UTE

    Why would you disconnect top hose, you probably would only let more air in there, the whole idea of having a bleed screw is to avoid this. This bleed screew is located on the highest point of the system , let the pressure build up and bleed a few times to make sure as when your system may need to blow air out of heater core etc.
     
  7. deserthead

    deserthead Well-Known Member

    Messages:
    1,068
    Likes Received:
    65
    Trophy Points:
    48
    Joined:
    Oct 20, 2004
    Location:
    Cairns QLD
    Members Ride:
    VS III l67 Column Shift Ute
    What about the knock sensors? You need to remove these to completely drain the block of all old fluid.
     
  8. wal

    wal New Member

    Messages:
    39
    Likes Received:
    0
    Trophy Points:
    0
    Joined:
    Jun 9, 2005
    Location:
    liverpool sydney
    Members Ride:
    vt executive v6/vc commodores
    what about the 2 or 3 pills your supposed to put in the top radiator hose the supposed to seal the water pump or somthing of the sort .....are they nessecary...wal
     
  9. Shounak

    Shounak The Kicking Horse

    Messages:
    2,499
    Likes Received:
    60
    Trophy Points:
    0
    Joined:
    Apr 20, 2005
    Location:
    Vic
    Members Ride:
    VX Executive S2 + XF Panel Van Project
    It certainly wouldn't hurt. A lot of people don't use them, but they'll only do good..

    For $5 from the Holden dealer, why wouldn't you?
     
  10. ChRiDDa

    ChRiDDa Active Member

    Messages:
    704
    Likes Received:
    104
    Trophy Points:
    43
    Joined:
    Jan 25, 2004
    Location:
    N/A
    Members Ride:
    VE SS-Z Sportwagon
    you dont need to remove the knock sensors for this process, as removing the heater hose on the RHS flushes through the block also... group this together with removing the thermostat and flushing through the top housing, only clean water will remain in the block
     
  11. ChRiDDa

    ChRiDDa Active Member

    Messages:
    704
    Likes Received:
    104
    Trophy Points:
    43
    Joined:
    Jan 25, 2004
    Location:
    N/A
    Members Ride:
    VE SS-Z Sportwagon
    i dont bother with these coolant tablets to be honest.. as they are not to protect the waterpump.. when the VS commodore came out, holden offered it with a 3 year extended warranty.. now the purpose of the coolant tablets was to seal any minute holes in the radiator/cooling system that would see the car come back under warranty for repairs...
    if the seal in the water pump is going to perish, its going to perish whether the tablets are in the system or not
     
  12. ChRiDDa

    ChRiDDa Active Member

    Messages:
    704
    Likes Received:
    104
    Trophy Points:
    43
    Joined:
    Jan 25, 2004
    Location:
    N/A
    Members Ride:
    VE SS-Z Sportwagon
    how would you be letting more air in, when the thermostat is closed? the air is exiting via the little valve in the thermostat
    as ive said before, this is the way i do it and always have.. it was the way i was also taught (i was a mechanic)
    if you want to do it your way, thats fine, im just providing advice as to which way i think its done. its up to you whether you chose to follow it or not
     
    commylad likes this.
  13. ssute57l

    ssute57l New Member

    Messages:
    223
    Likes Received:
    3
    Trophy Points:
    0
    Joined:
    Feb 11, 2006
    Members Ride:
    VYII SS UTE

    Thats fine, but im giving advise to you as a 21yrs old former mech the correct procedure to bleeding air out of a V6 holden motor, i will do it my way as this is the recomended procedure.

    If air is comming out of the thermostate, fluid is replacing it from the top hose so now there is a air gap, if however you open a bleed valve and the air travells to the highest point and bleeds out under pressure then there is no chance of air replacing it, only coolant from your resevior.

    I don't know everything but i try to give the right advise, just couse you were taught a certain way doesn't mean it is correct, listen and learn, nobody is shooting you down!!!
     
    Last edited: May 25, 2006
  14. Shounak

    Shounak The Kicking Horse

    Messages:
    2,499
    Likes Received:
    60
    Trophy Points:
    0
    Joined:
    Apr 20, 2005
    Location:
    Vic
    Members Ride:
    VX Executive S2 + XF Panel Van Project
    Chridda.. The images are gone..

    If you want me to host them for you, I'd very happily do it for you..
     
  15. ChRiDDa

    ChRiDDa Active Member

    Messages:
    704
    Likes Received:
    104
    Trophy Points:
    43
    Joined:
    Jan 25, 2004
    Location:
    N/A
    Members Ride:
    VE SS-Z Sportwagon
    ahh yes.. whoopsies! sorry bout that lads, changed to another website but i forgot to update the links!
    Thanks heaps for the offer Shounak
    got a few more FAQ's coming up, might need some assistance in storing some images, as i think im just about at the limit with my optusnet account
    Cheers!
     
  16. Shounak

    Shounak The Kicking Horse

    Messages:
    2,499
    Likes Received:
    60
    Trophy Points:
    0
    Joined:
    Apr 20, 2005
    Location:
    Vic
    Members Ride:
    VX Executive S2 + XF Panel Van Project
    No worries mate.. I've got 10-20mb of bandwidth (possibly more) just gathering dust with my ISP..

    You could also use image shack, it's free..
     
  17. groucho

    groucho New Member

    Messages:
    28
    Likes Received:
    0
    Trophy Points:
    0
    Joined:
    Mar 27, 2006
    Time warp

    Bloody hell free advice is great we can either accept or refuse it but....... at the top of the page you made a disclaimer that you WERE'NT a mechanic several entries later you are. I want this light speed apprenticeship please. Details of course?:my:
     
  18. ChRiDDa

    ChRiDDa Active Member

    Messages:
    704
    Likes Received:
    104
    Trophy Points:
    43
    Joined:
    Jan 25, 2004
    Location:
    N/A
    Members Ride:
    VE SS-Z Sportwagon
    i WAS a mechanic, for around 9 months or so, until i decided it wasnt for time and that i wanted to head back to uni!
    did a certificate II in automotive - light vehicle at swinburne!
    that was it :yeah:
     
  19. 90VN55

    90VN55 New Member

    Messages:
    801
    Likes Received:
    4
    Trophy Points:
    0
    Joined:
    Jan 1, 2006
    Location:
    stanthorpe, qld
    Members Ride:
    90 VN SS 5speed, '90 VN Calais 5speed
    does anyone know how to bleed the air out on a series 1 vn?
    cause the thermostat is at the back of the engine and you cant get to it.
     
  20. Shortstuff

    Shortstuff Random

    Messages:
    692
    Likes Received:
    6
    Trophy Points:
    0
    Joined:
    May 22, 2006
    Location:
    Melbourne
    Members Ride:
    2016 Golf GTI PP
    Leave the pressure cap off the surge tank and run the car with the heater on full hot setting until the radiator fan cuts in. You will have to watch the tank carefully though, and be ready to put the pressure cap back on fast as it can rapidly overflow once the engine is at the temp where the fan cuts in.

    That's how i've done it in the past and not had trouble with airlocks or anything.
     
    90VN55 likes this.

Share This Page