4 replies to this topic

[Courtneybriton]

Does anyone have any instructions for retrofitting a radiator overflow in my 1995 Mini Sidewalk? It doesn't have one (maybe it used to?) and it over heats. I am replacing the thermostat as well as my heater core today and I don't have any idea on how to go about putting a overflow tank in...

 

Any pictures, tips, links, or suggestions are greatly appreciated.

[nicklouse]

Basically it connecTs to one of the hose outlets from the bottom rad hose. And you have a small hose from the stat housing to the tank.

[FlyingScot]

If you mean the original, it fits above the damper mounting under the passenger wing and connects on the stub next to the radiator cap.

1995 Sidewalk is an Spi only later MPi have the system described above.

Pic in post #8 http://www.theminifo...-up-engine-bay/

It won't have an effect on overheating...

FS

Edited by FlyingScot, 13 February 2015 - 10:30 PM.

[spiguy]

If you mean the original, it fits above the damper mounting under the passenger wing and connects on the stub next to the radiator cap.

1995 Sidewalk is an Spi only later MPi have the system described above.

Pic in post #8 http://www.theminifo...-up-engine-bay/

It won't have an effect on overheating...

FS

Agree with FS on this one. My 92 cooper Spi had one. However it was cracked, so I just removed it and left a length of rubber hose to allow any overflow to drain to the ground, which is the way it was always done on the older cars. I'm not sure why the expansion tank was introduced on the later cars (seems to have come in around 91) - maybe driven by environmental motives?

 

In any case, as FS says, fitting it won't help with an overheating problem it will just stop coolant loss. Depending on how bad the problem is you could end up just over pressurising the expansion tank mind you. In theory all being well, the system should be able to hold pressure at 15lbs without coolant loss (assuming a 15lb standard radiator cap is fitted).

 

Is your car actually overheating in terms of the gauge showing it is overheating, or are you basing this on the fact that coolant is coming out the overflow pipe? Are you sure you have a 15lb radiator cap fitted? There are 13lb and 7lb ones available, and even ones with no pressure spring at all.

 

EDIT - meant to say,  you might find it tricky to get hold of one. I think this is it though :

 

http://www.somerford...roducts_id=5990

 

Picture looks a bit different to mine, but the description suggests its the right one. Maybe not much use to you in your location!  Though I would tend not to bother fitting it. Get the coolant system working correctly, fit a standard 15lb radiator cap and secure a length of rubber hose as a drain hose adjacent to the shock absorber.

Edited by carlukemini, 13 February 2015 - 11:01 PM.

[nicklouse]

Ahh me getting confused with the Spi and Mpis.

Side mounted rad does not need one.

Look at fuelling/ignition settings or engine tests such as a compression test.