22 replies to this topic

[timmy850]

You have a few options:

Use a normal cap and the excess ends up on the floor. Once it gets to the normal operating level it won’t spit any more out. This is how all early minis are

Use a normal cap and capture the overflow into a container. The excess will end up in the container but won’t get drawn back into the radiator

Swap to a recovery cap and container. The excess will come out when it heats up, then when it cools it’ll draw back into the radiator

[Rubbershorts]

You have a few options:

Use a normal cap and the excess ends up on the floor. Once it gets to the normal operating level it won’t spit any more out. This is how all early minis are

Use a normal cap and capture the overflow into a container. The excess will end up in the container but won’t get drawn back into the radiator

Swap to a recovery cap and container. The excess will come out when it heats up, then when it cools it’ll draw back into the radiator

Thanks Timmy. Would you agree with Viz that the tank works if vented? If so, it sounds like I only need to change to the correct cap and that would be correct as per your option three.

[Ethel]

I was wondering the same - it will siphon back (vented) if the level in the tank is higher than the level in the radiator.

[viz139]

The level isn't important because the hose is at the bottom of the tank , the coolant is drawn back in by a vacuum created by the cooling .I have seen it twice on IMM trips to sunny countries were cars running hot ( not overheating) were sorted by fitting the correct rad cap and putting some coolant in the tank. Because the hose is at the bottom it can become blocked with sludge over time. I also found the plastic moulding at the hose outlet is not great and worth carefully running a drill through to clean it up.

[Rubbershorts]

The level isn't important because the hose is at the bottom of the tank , the coolant is drawn back in by a vacuum created by the cooling .I have seen it twice on IMM trips to sunny countries were cars running hot ( not overheating) were sorted by fitting the correct rad cap and putting some coolant in the tank. Because the hose is at the bottom it can become blocked with sludge over time. I also found the plastic moulding at the hose outlet is not great and worth carefully running a drill through to clean it up.

Brilliant stuff, cheers Viz. I'll replace the cap.

[timmy850]

You have a few options:

Use a normal cap and the excess ends up on the floor. Once it gets to the normal operating level it won’t spit any more out. This is how all early minis are

Use a normal cap and capture the overflow into a container. The excess will end up in the container but won’t get drawn back into the radiator

Swap to a recovery cap and container. The excess will come out when it heats up, then when it cools it’ll draw back into the radiator

Thanks Timmy. Would you agree with Viz that the tank works if vented? If so, it sounds like I only need to change to the correct cap and that would be correct as per your option three.

Yes you’ll need a vented cap, or it won’t be happy! I’m just using an bottle at the moment as it works fine, as long as the overflow pipe from the rad goes to the bottom of the bottle

[Ethel]

The level will matter to some degree. If it blows water out, there'll obviously be less left in the radiator, potentially creating some vacuum if no air can get in to replace it, but the radiator hoses can compress reducing it.

 

I suspect the tank is supposed to be vented. If it wasn't the level could raise or drop by more than a couple of inches when you took the rad cap off, just because of the weather. It'd be easy to top up the radiator to above the level of the overflow pipe and see what level the tank tank fills to.

[viz139]

If I remember correctly there is a small vent in the tank as well as the two holes in the rivets. Don't have one handy to check. It is possible the tank by over filling the rad but it is very slow, I usually remove the hose at the rad end and use a small funnel. A syringe would also work.