The MGF Register Forums

Hi All,
Earlier this week I fitted B & G’s CL alarm kit. It’s working perfectly I.e. the self test does its thing every ignition and I tested the float before I piped the tank up.
In the original tank the coolant level was up the ridge about halfway up the tank. Now the level is as per the photo.
I need to add that at the same time as the CL kit was fitted I replaced the radiator bleed screw and lost about an egg cup full of coolant. When changing the tanks I siphoned out the original coolant into a 1 litre bottle that over flowed a little. I then put the coolant back in from the bottle. So, if anything the coolant level should be slightly lower. My first thought is there’s some air got in and if so it’ll need bleeding. Your thoughts on this would be helpful.
The temperature gauge is as it has always been and I’ve probably done about 10-15 miles since.
Cheers,
Michael.

Photo?

Ah yes! Well spotted. SMH Cheers.

I would let it have a few cooling and heating cycles to establish the level before undertaking anything possibly unnecessary - the levels tend to settle after disturbance. The radiator cap is lower than the coolant reservoir so some water should have come out but no air should have got in up front.

Thanks Charles,
Reassuring to know. I’m pretty sure if any air got in it’d have been in the large pipe under the tank as I changed it over.
Cheers,
Michael.

Charless wrote: ↑

Sun Aug 13, 2023 9:05 am

I would let it have a few cooling and heating cycles to establish the level before undertaking anything possibly unnecessary - the levels tend to settle after disturbance. The radiator cap is lower than the coolant reservoir so some water should have come out but no air should have got in up front.

Good advice. In one sense I'm lucky as I park on my drive facing downhill, so over over time any entrained air finds it's way uphill

If your old header tank is ok, you might think about using it as a test facility for the pressure cap. If you're handy and have some sort of variable low pressure air supply.
I've been testing my old yellow Halfords cap for the last 17 years and it is still ok, lifting and re-setting on release of air pressure at the correct pressures. I still carry an OEM cap as a "spare" just in case.

For the next person doing this job:

I changed my old weeping tank with a new one recently,
by strapping the feed pipe up to the boot lid it's possible to make the opening the highest point in the system, As you can see it's rough and dirty with some duct tape, but it works.

The red staining is where the old tank was dribbling. The new one is much better as I can now
actually see the coolant level

Thanks to all who took the time to reply.
Robbo, I did a variation of your method. I wedged a lump of wood under the bottom pipe to keep it as high as possible.
The level seems to have stayed where it was with no issues. I must have done a good 75 miles now so think it’s ok.
Cheers,
Michael.

Its well worth fitting a low coolant alarm. Ive fitted Bruce Cotsell's alarms to both my 115 and 135. On the 135 i decided to incorporate a variable delay unit to avoid false positives during hard cornering.
Not that ive actually had any false positives but as the delay units are 2x for £ 4.95 on Ebay and very easy to wire in it seemed a no brainer