12 replies to this topic

[mrducati]

I installed a new heater-matrix yesterday. It worked fine but had a small leak, so I took it out, fixed the leak and put it in again. Now it blows totally cold. I figure it must be an air lock. How do I get rid of the air lock? I have tried to squeeze the top radiator hose (front radiator), but no improvement.

[AVV IT]

You can try running the engine at idle from cold with the rad cap off until it gets to temperature (i.e. the thermostat opens), but I've never actually had much success with that method personally, so I always prime the heater circuit with a garden hose and prurge the system of any air locks instead.

 

Disconnect the heater inlet & outlet hoses at the bulk head then connect a garden hose to the inlet and a spare length of hose running to a bucket to the outlet, using some jubilee clips (see pic below). Then turn the garden hose on and flush through into the bucket until the water runs clear, be careful not to use full mains water pressure though, as that is likely to blow holes in your new matrix. When you have flushed the matrix, connect the hoses back up again and run the engine until it gets up to temperature, with the heater valve open and the radiator cap off, then check to see if the heater is producing any warm air.

 

 

EDIT: The pic is actually from a late carb model, but the plumbing for the heater circuit is the same as for Spi models

[lewBlew]

I am doing the same as the OP, but is there a way of doing this without mains water? Unfortunately my garage does not have a hose nearby

[AVV IT]

I am doing the same as the OP, but is there a way of doing this without mains water? Unfortunately my garage does not have a hose nearby

 

 

I think someone here reckoned they did it by pouring water into the circuit from a jug, and then blowing it around the circuit. Although I'm not sure know how they managed that without forcing even more into the system though. Can't you try bringing the "mountain to mohammed", and taking your mini to somewhere nearer a garden hose? Flushing the matrix is really only a ten minute job that requires a bucket, a length of hose and a screwdriver, so it really isn't something that needs to be done in the warmth of your garage. I've done mine in the street outside my house before.

[woody78]

I've always found bleeding the water system easiest with the front slightly higher than the rear. Doesn't need to be jacked up, even parked on a slight incline should be enough. Then with the engine idleing, and the heater on it should work

[lewBlew]

 

I am doing the same as the OP, but is there a way of doing this without mains water? Unfortunately my garage does not have a hose nearby

 

 

I think someone here reckoned they did it by pouring water into the circuit from a jug, and then blowing it around the circuit. Although I'm not sure know how they managed that without forcing even more into the system though. Can't you try bringing the "mountain to mohammed", and taking your mini to somewhere nearer a garden hose? Flushing the matrix is really only a ten minute job that requires a bucket, a length of hose and a screwdriver, so it really isn't something that needs to be done in the warmth of your garage. I've done mine in the street outside my house before.

 

 

Cheers. I'm sure I'll find someone with a hose somewhere.

[mrducati]

Thanks for your help folks! I do fear the gardenhose will be a bit stubborn now with 10 degrees C, but hopefully the heatgun will convince it to cooperate... I'll see if I'm able tomorrow.

[mrducati]

Back to step one. I now have heat in the heater, but also a new leak... I was very careful using a siphon (since my gardenhose is frozen) to bleed the radiator. How annoying!

[lewBlew]

Very annoying. Where's the leak, in the rad?

 

I'm afraid the Law of Sod always applies with Minis. When I mend one thing I always break another while doing it

[mrducati]

Very annoying. Where's the leak, in the rad?

 

I'm afraid the Law of Sod always applies with Minis. When I mend one thing I always break another while doing it

 

Yes the leak is in the rad.

I have to agree about the law of sod. 

[lewBlew]

I don't advocate things like Radweld but you might wish to give it a try. Although new rads aren't that expensive..

[mrducati]

I don't advocate things like Radweld but you might wish to give it a try. Although new rads aren't that expensive..

I agree Radweld might solve the problem, but Minis tend to need all the cooling they can get, so I'm hoping I can get a new matrix under warranty.

[lewBlew]

 

I don't advocate things like Radweld but you might wish to give it a try. Although new rads aren't that expensive..

I agree Radweld might solve the problem, but Minis tend to need all the cooling they can get, so I'm hoping I can get a new matrix under warranty.

 

 

I'm not sure you'll get Rover to honour that

 

Jokes!