Info needed: Morris C8 radiator

[pauldavies]

Thanks Mike and I have installed the cap assembly with some loctite high temp sealant and have left it for a couple of days to go off and will fire it up this morning, very hopeful it will do the job. In your radiators what releases the pressure?

[Richard Farrant]

Hi Paul,
This Air-Lock valve in the filler was also used on some Bedfords, like my QL. After owning it for about 30 years now it has never given any real trouble then about 3 years ago it started blowing water out of the cap intermittently and I removed the complete valve and checked it over. The spring had rust on it and was stopping full pressure of it onto the sleeve and sealing ring. I also found the screwed ring was not set correctly. Once I sorted this all out, and filled to the correct level (a bit lower than before) the blowing out stopped. Temp gauge only showed normal temp when water blew out, so doubt it was overheating.
Hope this is of some help.

regards, Richard

[Mike K]

Originally Posted by pauldavies

. In your radiators what releases the pressure?

As far as I know there is no pressure, its a thermo syphon system with the water pump as a backup The radiators on these trucks are large and wide . Maybe Richard F can provide more info ? Thanks Richard over to you

[pauldavies]

Hi guys and yes I went for a few runs in the C8 and on the last one it blew the coolant out which was a major disappointment, I do believe it is the spring as mine isn't bound with energy and the filler funnel was pitted but I honed that but it is wearing a bit thin. Any idea of NOS for those two? My temp gauge was on normal middle setting so it wasn't over-temping in fact it only took about ten minutes for it to be ok to refill prior to going home,
Regards
Paul

[Mike K]

Originally Posted by pauldavies

Hi guys and yes I went for a few runs in the C8 and on the last one it blew the coolant out which was a major disappointment, I do believe it is the spring as mine isn't bound with energy and the filler funnel was pitted but I honed that but it is wearing a bit thin. Any idea of NOS for those two? My temp gauge was on normal middle setting so it wasn't over-temping in fact it only took about ten minutes for it to be ok to refill prior to going home,
Regards
Paul

What is the pressure level you have just before it blows ? Might be worthwhile fitting a pressure gauge on it and go for a drive . The spring might be functioning correctly and doing what it is designed to do, release pressure above a certain psi.

[pauldavies]

Will check in the morning as I looked at the needle just before it blew but it wasn't past the middle of the gauge, I was only going slow and when I got back home I let it settle before switching off. It was fine, with all this coolant on the engine it shorted the spark plugs and caused a couple of backfires. I have the original spark plug steel caps so I will get some rubber caps tomorrow as the back fires cause the exhaust to split, I have been through two exhausts so far. Will keep you posted.
Paul

[pauldavies]

Checked the temp when the rad blew and it was only 140 which isn't running temp, on these old vehicles is 160. I have stripped out the assembly and cleaned and honed everything, I reassembled and screwed the ring past the 9/16 mark then applied the sealant which worked very well on the previous go and screwed the ring back up till on the 9/16. This makes the rubber seal and funnel seal that much cleaner and sealant only on the threaded part. Will give a day to get the sealant to set then give it another go.
Spring isn't the best I feel.
Paul

[Mike K]

Originally Posted by pauldavies

Spring isn't the best I feel.
Paul

. In theory if the spring is weaker than is specified, it will release pressure before it should do i.e. at a lower psi . Yes try replacing the spring .