UNDER PRESSURE

[SAP]

Hi - not sure if this has been mentioned on the forum before - but if anybody could advise if I have a problem or not - here goes:

Drove car to spares day from Grimsby so good run there and back no problem temp fine nothing above half way.

Put car away and today got car out and was checking levels and took pressure cap off the expansion bottle - (slowly) and there was bubbling and escaping air? a lot in fact , after removing cap bottle was almost full ? took radiator brass screw off and the water level was down - so transferred from the bottle to raidiator so had decent level in raidiator and expansion bottle back to normal just below quarter full (have not run car today)

Car is 1972 (MK1 ) - have no leaks - pressure cap is 20lb / good antifreeze - no sign of water in oil -

Do I have a problem ?? or start of a problem!!


cheers Steve

[GDPR]

imported post

Was it warm/hot when you took the cap off? If so bubbling is fairly normal.

If you take the brass bung out of the rad when the pressure cap is off, it will transfer from the rad to the expansion tank by siphon.....

[singapore stag]

imported post

Hi, I had a similar problem, expansion bootle full and lots of air and pressure,Chris (V MAD) suggested it MAY be the head gasket, he is going to check it out for me, he did say it MAY be thats about all.

[SAP]

imported post

Hi, car had been stood since Sunday - and not warmed or started since -

pressure cap takken off 1st and then the brass nut from radiator afterwards

Steve

[V Mad]

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When I had this problem on a car recently, the symptoms were the same. The expansion bottle was always full, and under pressure, even in winter. After fixing the head gasket there was virtually no pressure in the system, even when hot.

Try taking out all plugs, and crank the engine on the starter. See if any water spits out of the plug holes (mine did!).

[revbra]

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hi mine did the same it turned out to be the cap it had a small nick in the rubber so slowly lossing pressure not allowing water to return to the rad

[SAP]

imported post

revbra wrote:

hi mine did the same it turned out to be the cap it had a small nick in the rubber so slowly lossing pressure not allowing water to return to the rad

Tanks will try new cap 1st and if no change will go down the cyl/head route Steve

[iani]

imported post

revbra wrote:

hi mine did the same it turned out to be the cap it had a small nick in the rubber so slowly lossing pressure not allowing water to return to the rad

Should the cap have the rubber? mine doesn't and when I bought a new one at Stoneleigh the stallholder said I should probably remove it from the new one.



Ian

[MB]

imported post

Check the expansion bottle neck is also not weeping, this can also let the rad siphon into the bottle. Not sure how the neck is sealed to the bottle? I assume its supposed to be a compression fit. Had to use a sealant on my one as neck was loose.