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1.9 Watercooled petrol coolant leak
Posted: 18 Feb 2008, 11:08
by mal0r
All, on the way back from the Dubfreeze, I noticed my temp gauge wouldn't stop flashing. Cold I thought, but no. Stayed on all the way home. At first, thought it was just low-coolant. I topped it up, only to find a leak from somewhere under the engine block.
The main expansion tank stays full for a good while, but the expansion/top-up tank does empty after a few miles. I can see air bubbling into the main tank, but no crack or loose hose connections.
The coolant seems to be dripping off the bottom strut of the engine block, and not from any entry/exit points on the engine itself. Temperature stays fine until obviously the coolant level gets too low.
Is there a hose that I just haven't seen anywhere in that location?
Posted: 18 Feb 2008, 11:18
by Ian Hulley
Is it running out from the gland in the bottom of the waterpump ? This can run down and appear to be coming from the injun itself (bu&&ered water swatter

) .... OR the 'J' tube to the left side of the engine as you look from behind, these rot out oalong the bottom despite looking like new on the top

.
Ian.
Posted: 18 Feb 2008, 11:37
by mal0r
I'll double check everything with a torch I think. Sun was a bit in my eyes when looking from above. Just hope there's no bl00min' crack in the engine case. Cheers Mr H.
Posted: 18 Feb 2008, 11:43
by Ian Hulley
mal0r wrote: Just hope there's no bl00min' crack in the engine case. Cheers Mr H.
If it's none of those I mentioned it COULD be a waterjacket seal
Ian
Posted: 19 Feb 2008, 12:40
by Nicola&Tony
Ian Hulley wrote:Is it running out from the gland in the bottom of the waterpump ? This can run down and appear to be coming from the injun itself . . .
Rings a bell with me! Release the tension on the vee belt, then remove the belt and try to wiggle the pulley wheel that's attached to the water pump. If there's movement around the pump spindle / bearing then it's time to fit a new one.
Sounds like it was cold at Dubfreeze, do you know how much anti-freeze you had in your cooling system?
Tony
Posted: 19 Feb 2008, 12:53
by mal0r
Looks like it'll be a weekend job so I've got some daylight to check things over. Nicola and Tony, there should have been a fairly healthy mix of anti-freeze in there, but I'd also topped up neat at a service station on the way home. I know it's leaking because I needed another top-up when I'd got back and the gauge was creeping towards the hotter end of the scale when I wasn't getting enough wind on the radiator (i.e. town driving). I'd guess also the temp light continues flashing as a drop in pressure occurs?
Posted: 19 Feb 2008, 13:06
by toomanytoys
RED lights mean STOP... not keep going "coz its only 1 hour from home" etc etc...
So far you have been very lucky not to blow it up..
Have you bled the air out of the system at the rad too?
If you cannot see any leaks from hose joints etc, then you need to have a look behind the pushrod tube protectors, the main water jacket tends to leak if it isnt easy to see from any where else..
If it is the jacket seal then its really an engine out job.. and you have to consider if the studs are in good enough condition to withstand undoing...
Identify where the leak is coming from first..
Oh and dont be tempted to start adding "radweld", it rarely works and usually ends up blocking heaters and rads up...
Posted: 19 Feb 2008, 13:50
by mal0r
I consider myself told off toomanytoys! Although having a 4 month old in the back who needs to be home is a contributing factor when the temp gauge reads steady.
Posted: 23 Feb 2008, 14:56
by mal0r
Having spent a small while checking over pipes again and the pump, I see no leaks, but have thought it might a good idea to try a presure test. The kits seem expensive, and wondered if I could get the same effect by using my footpump with a presure gauge on it pushed into a much cheaper new expansion tank cap?
But I wouldn't know really what kind of pressure to use. Anyone got some advice? Thanks for any in advance.
Posted: 23 Feb 2008, 15:24
by funbus1
Undo the two screws that fix down your expansion tank lift forward and check for a split along the seam at back of tank. Happend to me, And only leaked under pressure. Just a thought. Rick.
Posted: 23 Feb 2008, 16:30
by mal0r
Aye, cheers, the seem to look like a bad idea doesn't it? Surely a sealed unit without a seem would have been a bit more robust. That said, I have no obvious leak from it when the water pump is operating.
Posted: 23 Feb 2008, 17:00
by Rozzo
Posted: 23 Feb 2008, 17:01
by funbus1
As said, only under pressure, Let ur bus tick over for 15-20 mins, have a beer or a smoke or both, when water starts to drip or pour out, have a wee look underneath, itll give you some clues to where its comming from.

Posted: 23 Feb 2008, 17:07
by funbus1
Aye rozzo, I had 5 Aircooled busses before this 1, and apart from a crankshaft oil seal job on 1, never put a spanner near them. Like the heater though.

Posted: 23 Feb 2008, 20:50
by Nicola&Tony
mal0r wrote: . . . but have thought it might a good idea to try a presure test. The kits seem expensive, and wondered if I could get the same effect by using my footpump with a presure gauge on it pushed into a much cheaper new expansion tank cap?
But I wouldn't know really what kind of pressure to use. Anyone got some advice? Thanks for any in advance.
Running a pressure test . . . is this different to getting the engine up to temperature and having a careful look around?
Tony