Hi all,

Started the process of re-hauling the cooling system - tried to pull the radiator today and ran into a few surprises. While the shroud above was mostly fine to take apart, the radiator bleed pipe itself was another story. The nut would not budge, but moved the entire bleed pipe itself. Trying to turn it more just ended up bending the bleed pipe itself, so I stopped before it bent too much. My option at this point seems to be to just bend it to loosen the nut enough so that I can remove the shroud and then buy a replacement bleed pipe (unless an alternative part/solution exists). Has anyone else run into this before? All the videos I've seen that nut just takes a small twist,




Any advice would be appreciated,

Cheers,

 

That pipe is NLA, so be careful. The banjo bolt goes into the radiator, is it jammed to the banjo or jammed to the radiator? If jammed to the banjo, and it is slightly loose in the radiator, I would try some anti-seize for a few days and then, hold the banjo tight in a pair of Mole grips and turn the bolt to loosen it from the banjo.
The important bit of the bleed pipe is the other end which has the venturi-effect suction stuff in it. Diagramatically this is how it works:

 

Antisieze and thermal shock - you need a focussed heat source and it needs to be a good one as that spot is aimed at moving heat - soak as recommended - then get some heat focussed on the banjo bolt, then hit it with something cold.

I will however make an observation - if the pipe moved toward the front of the car as it appears in the image when you were undoing then you're going the wrong way - sorry if this seems obvious - you may actually have twisted the fitting in the top of the rad I doubt the pipe will move in isolation.

One other suggestion is a suitable socket on an impact driver - provides impact but isn't so brutal as a full fledged rattle gun.

 

So I left some anti seize on it over night and had another crack this morning, no luck. Tried the impact driver as well, and nothing. The pipe was indeed moving independently from the bolt (it would spin 360 if I didn't have the hood on), hence why it looks as if I tried to turn it the wrong way around, I was trying to get a bit of space so the pipe itself didnt bend on the shroud if I slipped

I think Gregs idea might work if I leave it for a few days and buy a better pair of grips, it seemed to work in terms of getting some resistance on the nut without bending the pipes, but the grips I was using kept slipping.

If not, there's always a blow torch purchase in my future I guess?

 

If the banjo is moving independently of the bolt, then the problem is that the bolt is seized into the radiator. SO Mole grips are not needed just keep on with the anti seize and then us an impact gun and hope for the best.

 

Don't think that you need to always rotate to undo. Back in my days in the trade the first thing we did with bolts that we knew would present trouble is to actually pinch them a little tighter but that option may not be open to you now. If this is galvanic / dissimilar metal based corrosion it is close to being wleded together, such things are a real challenge, once the threads start to gall the locallised heating literally helps weld things together - I had the same issue with 3 bolts in my cylinder head coolant rails.

What are you using as a freeing agent ? - if it is WD40 cease and desist immediately - WD40 is not a release agent. There are many on the market that claim all kinds of miracles, one that I use that doesn't get much of a look in is Arrow chemicals ZX54 - this is the penetrant of choice in the defence arena here in the UK - not sure how available it is in Oz. I use ZX54 or Bilt Hamber Ferrosol (ZX54 can be hard to get sometimes) - or I make my own with ATF and Acetone - and don't underrate the properties of Diesel fuel to release things. Mouse milk is another good one you don't hear a lot about.

Heat is your friend but may not be your solution - the rad is designed to get rid of heat as fast as possible so a blowtorch wasn't what I had in mind - you need something a little more serious but with that comes risk because you could release solder joints if you're too enthusiastic.

Try to tighten a little - I know this is counter intuitive - if you can't tighten or release I won't sugar coat - you're in trouble - but you should know that Rad's are replaceable, that bleed line on the other hand is not the part to sacrifice. Because you have the banjo bolt head exposed and it is flat it is a very simple matter to centre punch it, if the bonnet is out of the way it is a pretty easy place to drill square - with a small enough or right angled drill the bonnet can stay. Worst case I'd be looking to drill that bolt so the head comes off - the biggest drill is not the first you should use but I wouldn't go much bigger than 8.5mm assuming you keep it square to the bolt. If you can get down the centre you should be able to peel the threads out eventually with minimal damage to pipe and radiator.