23 replies to this topic

[nev_payne]

I've had a rad cap blow off on Geroge back along - that was due to the massive ammount of air in the water system however - and my inexperience of bleeding a system so I'd say a deffinant coolant bleed through would help out there.

[frownies]

My garage have now told me my old radiator only holds two thirds of water that the new one they are going to fit tomorrow does...Do u think this will be be an end to my problems...?? Answers gratefully recieved

[minislapper]

You've taken it back to the same garage? :-o

Do you have a very large wallet? If the radiator is knackered then they should have spotted this when they did the other work. If they are fitting a different one and telling you it's the wrong size then I think they're spinning you a line again.

Flushing the system and checking for air locks and checking all the things mentioned about (which you could do yourself) should have been the first step. Forking out for more new parts which probably aren't necessary is just not right on their part.

[Jammy]

Besides, the amount of water a radiator holds is not as important as the surface area of the effective cooling area. A standard rad should be easily up to the job of keeping anything upto a moderately tuned engine cool.

They may however have stumbled on the problem IF the old rad was rusting inside.

[minislapper]

But if they've fitted a new water pump the rad would have been off anyway........! If the water coming out was proper rusty coloured, they would have noticed !!!

[Dan]

The standard cooling system is more than up to cooling the standard engine, it does struggle a bit on the auto from time to time but not as much as you've described here. Your garage need to find out what is actually wrong first before fitting an uprated rad as there definitely is a problem by the sound of it and they aren't fixing it they're just ignoring it. Go to a different garage.

[midwestmini]

The cooling system should indeed be pressuirised, that's how it avoids boiling. It can run up to 18 psi on most Minis, that's quite enough to blow the cap off if you turn it and to blow steam out of the overflow. Even if the gasket has gone, skimming it as a matter of course is an over reaction by someone who has learned his trade on alloy headed cars and certainly not Minis. Cast iron heads rarely warp as a result of overheating and sometimes a gasket fails for no other reason than it's age. Certainly get the head measured for flatness but to assume it will need skimming anyway is a great way to skim your wallet. It could be the head gasket but it might not. As above, if you can't do this yourself then find a Mini friendly garage who can. The cooling system needs stripping down and reassembly. Is the fan on the right way around?

Who here can provide a surefire way to purge an airlock from the cooling system?

I'll start by say I've heard of the following three ways but I've not had much luck
1- burping (squeezing the hoses)
2- disconnecting heater hose at the valve and backfilling through the heater until water comes back through the valve
3-leaving the radiator cap off for 15 minutes etc.

Anyone?

[Matt]

turn the heater on.. and top up the water until it stops swallowing.. *how they bleed mid engined cars*

[Leigh Roberts]

turn the heater on.. and top up the water until it stops swallowing.. *how they bleed mid engined cars*

To rule out the head they could give it a leakage test, at least then they would know its the cooling system and not the head before you look at getting it skimmed.

id get it running and check all the pipes including the ones to the heater but make sure valve is open.