cooling system bleeding

[jatsvl]

will a decent sized funnel with about six inches of hose (radiator hose that will match the size of the filler ) fitted so the water level (when filling) is above the highest point of the head/plenium chamber, bleed all the air from the system without opening the bleeder valves on the plenium chamber and the top hose fitting? I have been using this method when flushing my system and have had no problems. I would like to know if anyone else uses this method and what your results are.(I should post a photo of the funnel but don't have one handy I will try to post it cos' I think it is a great idea).

[bangers]

you have to open the hose so the air has someway of getting out. i don't recommend the bleeder bolt cos they are usually corroded in and snap when you try to undo it. my mechanic taught me to take the hose off with the bottle and hose method.

[harry3]

some say the hose on the intake manifold can be removed if the bleeder bolts are corroded in place

I think you risk a steamtrap and cracked head unless you let the air out someway
some suggest forcing water in by squeezing a large plastic soft drink bottle

I undo both bleeded bolts then force water in with a garden hose into the radiator filler, with rag wrapped around it for a seal
obviously not suitable for a roadside cooling system repair

[Dose Pipe]

you could always make up a old radiator cap with a peice of pipe on top, and then just fill that to the top, then you can be 100% sure its got no air in the system

[harry3]

there must be some way for the air in there to get out or the water you need to be in there cant get in

the bleeder bolt threads should be coated in grease when ever removed

[jatsvl]

so long as the water level is above the highest point the air would be pushed out through the radiator filler/funnel, physics!

[Heefers]

Sorry Jats but not entirely correct. It won't matter how high the water level is where your are filling from (radiator cap) if there is a cavity (water jackets) above the entry point (top radiator hose) with air in it and nowhere for the air to escape to. Even if you found some way to force water into the radiator all you would succeed in doing is compressing the air in that cavity. That is why manufacturers place bleeder valves in the top most point of their cooling system to allow the air to escape and be replaced by water. Cheers, Heefers

[Dose Pipe]

I'm prity sure he has the right idea, hes just writen it so it doesnt make much sence.

[Heefers]

To show in effect what I have tried to explain, do a little bit of experimenting with a couple of coke bottles and a small length of garden hose. A little bit of bong making experience is a plus here so if you've got a hippy cousin it's a good time to give him a call.

1. Make a hole half way up the side of one bottle and insert small length of hose.

2. Make a hole at bottom of second bottle and join hose. Make sure you have a good seal where the hoses join the bottles, a bit of blue tack may be needed. This will also leave the second bottle higher than the first.

3. Screw the lid on the first bottle tight. This bottle represents your engine cooling system with the hose being your top radiator hose. The second bottle is your radiator.

4. Start filling the second bottle until it can't be filled anymore, you'll notice that the first bottle will only have filled up to the level of the hose. This simulates air being trapped inside the water jackets that are higher than your top radiator hose.

5. Slowly unscrew the cap on the first bottle, this allows the air to escape and be replaced with water from the second bottle, simulating the effects of unscrewing your bleeder valve.

You can try doing a few different things while the air is trapped inside the first bottle like putting the lid on the second bottle and squeezing (simulating the theory that if water is forced into the radiator it will push out the air from the engine, note this will fail, all you may do is compress the air a little) or any other tricks that you have been told about. Have a bit of a play but i guarantee you won't beat physics.

I hope that this drives home the importance of releasing your bleeder valves when filling your cooling systems.

Cheers, heefers

P.S. When changing the cooling fluids I use de-mineralised water from Coles or Woolies as this helps prevent mineral deposits forming in your cooling system. At a around $2.30 for 2 litres it's not bad insurance.

[sponge]

Chuck some pictures on

[gungazza]

remove hose from waterbottle, insert small funnel into hose, hold hose up high and tape it to bonnet stay ,then undo lower bleed bolt ,pore water in funnel till water comes out of bleedhole ,replace nut then do the same to top bleeder easy

[Heefers]

Chuck some pictures on

I'll see how I go, not really sure how to post pics so have to wait for the missus to get up.

[Heefers]

Here goes, first time posting pics anywhere so sorry if it doesn't work!

Ah beauty, the pictures worked. As you can see in the first picture, the air in the water jackets above the level of the top radiator hose will prevent the water from the radiator filling these cavities. Once the bleeder valve was cracked open (pictures 2 &3) it allowed the air to escape from the cavity and the water levels to equalise between the radiator and water jackets filling them completely.

[harry3]

sorry but I cant understand

I think the only way you can get the air out is to force water in and that needs the bleeder valves both open

[Heefers]

You don't need to force water in (gravity will take care of that for you) but you're right, the bleeder valves definetely need to be opened in order to allow the air to escape and the water to enter. Cheers, Heefers

[jatsvl]

the two bottle experiment makes sense, clearly. however since you should fill the cooling system whilst the engine is running how would a water pump between the two bottles effect the experiment also shouldn't both bottles have an inlet and outlet so the water circulates and maybe under pressure force any air pocket back out of the radiator filler???

[Dose Pipe]

the water level needs to be the highest point

that is all

if you cant understand it yet pay a mechanic lol

[thug]

where abouts are the bleeder valves? and what do they look like?

[thug]

I found the valve right on the outlet. I was at the library looking at one of the manuals and they said with regards to refilling the radiator to just reomove the engine end of the outlet hose and hold it up high and fill the radiator until it comes out the engine refasten and bleed.

[Heefers]

I found the valve right on the outlet. I was at the library looking at one of the manuals and they said with regards to refilling the radiator to just reomove the engine end of the outlet hose and hold it up high and fill the radiator until it comes out the engine refasten and bleed.

Are you talking about the VL 3.0 engine or the VN 3.8 because the previously described procedure by gungazza is the correct procedure for the VL 3.0. Just looking at your ride details and thought you might've been thinking about the wrong engine.

[thug]

im changin the radiator on my vp v6 3.8( but also have a 2ltr berlina straight 4 (yeah)!)
Although starting to wonder which way is best ??

[thug]

yeah sorry i didnt realise i was in the wrong model forum, was just doing a general search