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Head gasket

Just a quick update, eventually removed head as water loss was getting worse, head was skimmed (found somewhere 2 kilometres away that area hydraulic pipe company but used to do engineering work and still have the machinery and spares, they did it for free !!!) and in the end I bought a gasket from the skimmers which was slightly thicker than the original. Then followed Malcolms advice about getting all the air out. It took 3 days to rid the system of all the air then a heater hose blew so I had to start again getting the air out. All seems well now, just need a better exhaust clamp as I cannot get a seal at the point just before the pipe passes through the wing.
 
Thank you, bought a new one on ebay.
Haynes has sold it out.
I hope it will turn out to be a good investment.
If someone, 2 years ago or earlier, asked me if I would like to learn something as a mechanic, I would have laughed at him. And now...
Fortunately, I am a curious man.

Andrea scripsit.
 
malcolm said:
Performance normally isn't affected by a head gasket failure - that does other annoying things like pushing water into the oil or blowing the water out of the system.

Sure there are posts on here about bleeding but essentially put the expansion bottle on top of the engine. Fill from the rad. Then squeeze the top hose to pump water into the engine. Undo the rad cap and let it fill from the expansion bottle (with the cap loose on that to allow water to move). Rinse and repeat. And turn the heater on and let the air out of the valve on that. I'll get Frederick to do a page on that.

But after overheating definitely bleed the system and try again. Those bubbles could well be air left in there after overheating - the thing that causes the water to fall out is boiling and that leaves air in there. And make sure the cooling system is pressurising properly - if there's a leak, perhaps a hose, water pump, radiator cap seal, or expansion bottle seal, the system will boil before it gets to the temperature necessary to turn the fan on. Pressurised cooling systems boil at a higher temperature than unpressurised ones, and the car is set up assuming a pressurised system.

Clean the connectors on the fan and the radiator thermostat. Connect the fan directly to make sure it comes on when it has electricity. Bleed the cooling system. Run the car, take it for a short drive and let it idle - the fan should switch on and off when it's hot before it bubbles.

If that works then wait until the following day. When the engine is completely cold bleed the system again if it needs it. Go for a drive (10km) and leave the car sulking in a corner until the following morning when it's cold again. Undo the expansion bottle cap and if it hisses then there's not the same quantity of stuff in there as there was yesterday and the head gasket needs doing. See above for good advice on that.
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I'm a new owner with potential head gasket failure (and I've only driven the car home back in March but noticed weeping from the hose connections). I'm confused. Someone on the Renault stand at the restoration show at the NEC said raise the expansion bottle and just fill from that and never remove or even loosen the cap on the radiator itself but the instructions here seem to contradict this. Also, with a BMC A or B series cast iron lump I'd change a head gasket in my sleep but with wet liners and a need for special tools, I'm beginning to wonder if this apparently straightforward job is beyond me. I know of the three excellent specialists in Louth, London and Sussex, but I'm in the Midlands; is there anyone a bit closer? I probably shouldn't drive the car now. Help!
 
Eccles60 said:
I'm a new owner with potential head gasket failure (and I've only driven the car home back in March but noticed weeping from the hose connections). I'm confused. Someone on the Renault stand at the restoration show at the NEC said raise the expansion bottle and just fill from that and never remove or even loosen the cap on the radiator itself but the instructions here seem to contradict this. Also, with a BMC A or B series cast iron lump I'd change a head gasket in my sleep but with wet liners and a need for special tools, I'm beginning to wonder if this apparently straightforward job is beyond me. I know of the three excellent specialists in Louth, London and Sussex, but I'm in the Midlands; is there anyone a bit closer? I probably shouldn't drive the car now. Help!
Click to expand...
I am wondering why you think the head gasket has gone if the only indication was weeping from the hose connections, have you done a compression test or are there other symptoms such as water in the oil.
 
ecurb.renots said:
I am wondering why you think the head gasket has gone if the only indication was weeping from the hose connections, have you done a compression test or are there other symptoms such as water in the oil.
Click to expand...

No, no sign of oil or water in wrong places but just the oozing from at least the top two radiator connections. Paul Cunningham in a separate conversation seems pretty certain it could be the head gasket and has helpfully suggested a few tests: CO probe in header tank, hard hoses after running and a hiss the next day when the cap is removed. A compression test would be a good Idea too and I thinking of getting a gasket test kit too. I've only driven the thing once over about 130 miles and it seem to run well but I get a little puddle on my garage floor. I must pluck up the courage to start it up, go for brief run and see what happens.

Thanks for your interest, I really appreciate it. I'm not sure if there's anyone around where I am in Solihull to meet up with and chat face to face about such matters.
 
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