Pressure in the cooling system

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Dextapaul
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Pressure in the cooling system

Post by Dextapaul »

Hi everyone. I'm having constant problems with pressure in the coolant system. With the cap on it blows coolant out of the overflow tube, with the cap off it comes out of the filler neck.

Because of this problem (there was also diesel vapour leaking out from the head gasket) i got the head crack tested (ok) and skimmed. I refitted with a new head gasket, properly torqued following the order etc etc. There are now no leaks from the head gasket and the engine runs lovely.

But..On tick over from cold, after 2 minutes water pours from the filler neck. What should I look at next?

John b
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Re: Pressure in the cooling system

Post by John b »

Before you get back to the engine, have you checked the radiator isn't blocked? Remove the bottom hose and run a hose pipe into the top, the water should pour through and not fill the radiator. Worth a try before before going any further
My biggest fear is that when i die my wife will sell my tractors for what i told her they cost

Dextapaul
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Re: Pressure in the cooling system

Post by Dextapaul »

I had the coolant draining out of the tap on the block to do some further investigations. It had virtually stopped running when i flicked out the thermostat. Loads of water suddenly poured out of the tap.
I've run it without the thermostat and it runs fine (thank god!!) so i wonder if there was an airlock.
I notice similar thermostats have a little tiny relief valve on the housing - I wonder if peoples suggestions on here to drill a 2.5mm dia hole to stop air locks is the reason.

Billy26F5
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Re: Pressure in the cooling system

Post by Billy26F5 »

What thermostat do you have? You should have a shrouded 154ºF thermostat (like the AC TF3), if you don't have the right thermostat get a correct replacement, TF3's are on eBay now and then. Test the thermostat before you fit it and don't subject it to sudden temperature changes as it will otherwise be damaged.
Sandy
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Dextapaul
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Re: Pressure in the cooling system

Post by Dextapaul »

Thanks Sandy, yes I have a AC TF3 type. I swapped it for the type with the little relief valve and have run it up to temperature with no problems.
Whilst it was hot I checked that there were no combustion gases entering the coolant using the dye kit and happily all is ok.

All is well. I am just looking now at how to obtain an age related plate for the Dexta as she is nearly ready for the road. :D :D
Pat Pawsey seems to be the man to speak to?

Billy26F5
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Re: Pressure in the cooling system

Post by Billy26F5 »

Pat Pawsey is indeed who you want to speak to. Good work with the thermostat.
Sandy
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Dextapaul
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Re: Pressure in the cooling system

Post by Dextapaul »

A quick service from Pat so i just need to get the bits of to DVLA now and thats another little bit sorted. :beer:

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