Fern Posted November 25, 2008 Share Posted November 25, 2008 So I was changing the water&anti-freeze. I suppose I was doing everything correct according to the book. But now I have air in the upper pipes which go to heater. When the engine is hot they look like pretty and nice sausages because of the inner air pressure. And one of that had cracked already. I think it's the upper point of coolant system, and I do not know how the air is going to get out of there. Is there any standard procedure that I should take to get rid of air? One told me that on some cars there is some kind of "valve" or "tap" for easing out the air from the upper point. Quote Link to comment Share on other sites More sharing options...
LRDISCOVERY Posted November 25, 2008 Share Posted November 25, 2008 So I was changing the water&anti-freeze. I suppose I was doing everything correct according to the book. But now I have air in the upper pipes which go to heater. When the engine is hot they look like pretty and nice sausages because of the inner air pressure. And one of that had cracked already.I think it's the upper point of coolant system, and I do not know how the air is going to get out of there. Is there any standard procedure that I should take to get rid of air? One told me that on some cars there is some kind of "valve" or "tap" for easing out the air from the upper point. Hi remove the plug on top of thermostat housing and top the water up through there this should get rid of any air in system.It; a black pastic plug use a socket to remove it and do not over tighten when refitting as it will snap. Quote Link to comment Share on other sites More sharing options...
First_Fleet Posted November 25, 2008 Share Posted November 25, 2008 Hi Fern. I don't know what engine you are referring to, but on a V8i I always make sure the radiator fill plug is at the highest point both side & length ways/wise. When I fitted a low coolant alarm I could not stop the buzzer operating which meant it had air in the system. What to do? What to do? Well, what I did was cut the bottom out of a 2 or 3 litre Coke bottle. Into the neck I fitted a 1/2" bsp nipple & clamped it in. (I think the correct thread is actually 22mm P ) I then screwed the coke bottle into the Rad tank. & with the Discov. on the cross slopes, I ran the engine until hot & with the overflow bottle cap on tight, the coolant expanded into the coke bottle. With me so far? Being a green colour (Castrol AB/AF) it was easy to see, & as the engine ran, a lot of air bubbles came out, big ones & small ones. The engine could be revved if necessary as the coolant expanded into the Coke bottle. When I was satisfied that most air was out, I let the engine idle & the level stabilise. I then slightly loosened the LR overflow bottle cap & the level in my Coke bottle dropped. When it got down to about an inch or so I unscrewed the Coke bottle & with coolant still purging slightly, I whipped the plug back into the radiator. I eventually did this operation one more time after a couple of weeks & it's been fine since then. **** NB Without the buzzer warning I could not know there was air in the system. Make sure you wear some decent waterproof gloves & if you don't have a brass rad. filler plug I suggest you get one before doing this, rather than leave the plastic one in place. Heath Robinson ain't in it. Hope this helps. I'm trying to post an image from my ISP Server but it's not working. Try this link instead. Seems that works ok. Visit My Website Quote Link to comment Share on other sites More sharing options...
Fern Posted November 25, 2008 Author Share Posted November 25, 2008 Oh, sure, I forgot, the engine is V8. But as far as I see on the pictures it's like on TDI (pretty the same). What you did is interesting, as far as I understand you got rid of air just in radiator. I also noticed that there is air if unscrew the plug on radiator. Then if you loosen the plug on tank then the level will raise and you just place the plug back in radiator. That's what I did. Quote Link to comment Share on other sites More sharing options...
First_Fleet Posted November 25, 2008 Share Posted November 25, 2008 As the rad. was at the highest point, all air was trapped or circulated to there & allowed to escape. It was the actual visual aspect that I needed to ensure it was all out because of the buzzer sounding. Quote Link to comment Share on other sites More sharing options...
Fern Posted November 25, 2008 Author Share Posted November 25, 2008 That's what I do not understand, if I have air in heater, thermostat etc how will it flow to radiator? And why it did not in my case? Quote Link to comment Share on other sites More sharing options...
Milemarker Type S Posted November 26, 2008 Share Posted November 26, 2008 I bled the air out of my heater by running the engine and loosening the heater pipes where they join the matrix... air and water bubbled out and when there was only water I tightened the hoses back up- job done. Quote Link to comment Share on other sites More sharing options...
Fern Posted November 26, 2008 Author Share Posted November 26, 2008 Good. Will follow all recommendations given. Thank you. Quote Link to comment Share on other sites More sharing options...
First_Fleet Posted November 26, 2008 Share Posted November 26, 2008 Following on from what Milemarker said, I have read where people have had a good result by reversing the heater hoses. Whether they were fitted incorrectly by the PO I don't know. Worth a look I suppose. Quote Link to comment Share on other sites More sharing options...
Fern Posted November 26, 2008 Author Share Posted November 26, 2008 Following on from what Milemarker said, I have read where people have had a good result by reversing the heater hoses. Whether they were fitted incorrectly by the PO I don't know. Worth a look I suppose. Can not believe that there is any difference how do the hoses go in or out the heater. It's just a loop of pipe in simple words. Or maybe there is some valve inside a heater which prevents air to get out? Don't think so. Quote Link to comment Share on other sites More sharing options...
First_Fleet Posted November 26, 2008 Share Posted November 26, 2008 Maybe the routing & levels are such that they can air lock ie. riser direction I've never seen one out so can't comment further. As I said, I have only read about it. Quote Link to comment Share on other sites More sharing options...
ThreeSheds Posted November 26, 2008 Share Posted November 26, 2008 Another vote for loosening the pipes - worked for me Can not believe that there is any difference how do the hoses go in or out the heater. It's just a loop of pipe in simple words. Or maybe there is some valve inside a heater which prevents air to get out? Don't think so. I agree that a valve of some sort in the matrix is 'unlikely'. There is certainly no valve that I could detect - blowing through the matrix from either end produced same results and I can think of no logical reason for one. It may be that when people reverse their pipes (as mentioned above) they are just allowing out the air in a similar way to loosening the pipes? With regard to the heater pipes becoming like sausages - if you mean that they are expanding under pressure then there is surely something wrong since the pressure in those pipes should be the same whether there is air or water in them. If they are ballooning (expanding) then (i) are they still serviceable? and (ii) was the level correct in the expansion tank? (If the expansion tank is filled to the top whith the cap screwed on, then the extra volume of expanded coolant has to go somewhere) Hope this helps. Roger Quote Link to comment Share on other sites More sharing options...
TheRecklessEngineer Posted November 26, 2008 Share Posted November 26, 2008 Are you sure there is air in the system? "Ballooning" heater pipes do not necessarily mean that there is air in the system, merely that there is pressure. Air in a TDi will work its way to the rad and the top of the thermostat housing - if there is no air at these points then you are fine. How badly do the heater pipes balloon? I've never heard of heater pipes doing this before, It may be worth replacing them. Quote Link to comment Share on other sites More sharing options...
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