8 replies to this topic

[lewBlew]

Right, after yesterday's leaking and overheating I'm 99% sure it is the bottom radiator hose which has failed. I've obtained a replacement, together with clamps and a replacement bypass hose (for giggles).

Am I right in thinking I need to do something like this:

1. Detach hose from bottom of radiator and leave to drain
2. Drain cylinder head - is this necessary? Suppose I might as well refresh the coolant while I'm at it
3. Detach bottom rad hose from heater hose and water pump - do I need to remove the radiator to do this?
4. Remove and replace bypass hose. I'm going with the collapsible type for now because I'm lazy
5. Attach new rad hose
6. Fill up with DI water & antifreeze - I usually do a cocktail of 50/50 measures
7. Let it run and warm up for a bit. Kill engine, let it cool, top up if necessary.

Sound about right? '91 Mini Mayfair 998 by the way.

[Beige]

I normally leave the bottom hose on the radiator and disconnect it from the water pump and heater hose, then lift the radiator out with the hose still attached. Sounds like more work but I've always found it quicker than faffing around trying to undo/refit the hose while the radiator is in :)

As for the bypass hose, don't skimp, I was going through a concertina hose every couple of weeks, fitted a proper hose and it's been fine for the last 7 years...

[lewBlew]

Thanks for the tips :)

[miniman24]

I do what Beige says, as the circlip at the rad side of the bottom hose is usually much rustier than the one on the water pump side - I had to cut mine off with a hacksaw when replacing my bottom hose a few weeks ago! Most of the water drains out well this way too. You may as well fit the proper bypass hose while the rads off, its a 10 min job to whip the water pump off, fit the new pipe and a new gasket and re-assemble :)

[tiger99]

I concur. A convoluted bypass hose may only last a couple of weeks, so you are only making a lot more work for yourself by using one.

Except for early models, it really is easiest to take the radiator out to fit the bottom hose, and supremely easy to take the water pump out to change the bypass hose for the proper type. I had to do that at the side of the road once, because a 2 week old convoluted bypass hose had burst. I shortened one of the heater hoses slightly to obtain a suitable piece of hose to replace it, and that lasted upwards of 60,000 miles, until the engine was worn out.

[Ryang556]

I do what Beige says, as the circlip at the rad side of the bottom hose is usually much rustier than the one on the water pump side - I had to cut mine off with a hacksaw when replacing my bottom hose a few weeks ago! Most of the water drains out well this way too. You may as well fit the proper bypass hose while the rads off, its a 10 min job to whip the water pump off, fit the new pipe and a new gasket and re-assemble :)

Getting hold of a water pump gasket from your local autostore is a pain in the ass though as me and my mate found out doing his bypass hose a few weeks ago, ended up buying a new pump just for the gasket!

[lewBlew]

Thanks guys. I haven't really got time to do the water pump tomorrow so i'm just going to do the bottom hose, which is the one that's leaking. There is a convoluted bypass hose on there at the moment which has been on for years and doesn't seem to be a problem... So I might just leave it and see what happens. I always have a spare.

[minimissionary]

Stick the hosepipe in the rad while all the hoses are on. Should give it a good wash out. Best to give it a back flush while you're at it.

[thebluepotato]

I am going to add my two penny's here.....do NOT use the recommended OE crappy bypass hose that is manufactured by the same cheap company. My new one lasted for 3.5 weeks (!!!!) and now is leaking where the hose seam line is down the middle - squirting like punctured beer can (the hose is manufactured by joining two pieces through a heating process). Go buy a foot long piece of heater hose that is strong and has good wall thickness and do it right. I have to tear down all my cooling again today and I am so peeved at the company who sold me this "original spec" hose. $2.00 USD part and now requires 2 hours on my time. Not fun!