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MG MGB Technical - filling radiator/colant

I know this has been on here before but I can't find it. I was sure I had it saved :(. Anyway following a previous post where I have a possible over pressure. I need a 'fool proof' i.e. ME! way of filling the cooling system so there are no air pockets (Or at least unlikely) I seem to recall something about jack the back and fill then the front. I have one of those annoying rads with the neck so doing it by level above fins is impossible.

TIA Bernie
B Anderson

Bernie,
Never had a problem. Fill it with heater valve open, run it till up to temp, i.e., thermostat open. Let it cool down, top up............never failed yet!
Allan Reeling

Snap. The MGBs I have had were no problem to fill. I didn't do anything special - just poured the coolant in the rad until it looked full (heater open of course). Ran the engine until warm. Topped up. No issues. No air locks.
Mike Howlett

If you feel uncertain, fill it up, drive the car up some ramps and squeeze the bottom hose a few times.

If you haven't got ramps, just squeeze the bottom hose.

Sometimes gets that occasional air bubble out.
John Bilham

If anything the front should be a little higher than the rear, the other way *is* likely to trap air. But a couple of heat-cool cycles especially if the car is being used will burp all the air out unless there is some other problem.

I assume you mean you have the angled neck, just fill till you can see coolant, and it will push out any excess. If you remove the cap when still *warm* (not hot!) and you can see coolant in the bottom of the neck then it is fine.
PaulH Solihull

I always disconnect the top radiator hose from the thermostat outlet.

Then loosen the clamp at the radiator so I can rotate the top radiator hose to point upwards.

Continually fill the system through the rotated top radiator hose until you see coolant coming out of the thermostat outlet.

This method puts the filling point higher than the entire cooling system.
Steven Rechter

You really don't need to go to those lengths on level ground or if the front of the car is slightly higher. Whatever you do to actually fill it there will always be bubbles of air stuck to the walls everywhere until you get the heat, vibration, flow and pressure of running, so it will always need to burp itself over a couple of heat-cool cycles.
PaulH Solihull

Thanks all. Borrowed a pressure tester yesterday and discovered a tiny leak via the kenlowe 'red sleeve' on the top hose. Had real fun trying to get it to seal but got there in the end. It will have to wait until the rain stops for a decent run out but I am a bit more hopeful that problem of ooverheat and losing water is solved.
Merry Christmas all. And safe speed in the new year.
Bernie
B Anderson

If you have a late model B, fill the reservoir up, start the car, squeeze the top and bottom coolant hoses coming from the radiator to and from the engine and keep them squeezed. You will feel the hoses start gurgling and giving resistance back until they are filled up all the way... You are assisting in the reservoir filling the coolant system and speeding up the process and having it fully filled. I dont have a thermostat fitted to my car so I dont have to wait for it to warm up, something I will address at a later date... So its quite easy for me. I actually did it two days ago.

Ive had the problem where it would over pressurize and spit it back out the overflow pipe when first getting her going this past summer. After that I topped up the reservoir and didnt have a problem the entire summer. Which I would attribute to fully filling the system when cold since I do not have a t stat ...
JRB Mr

yea sorry, didnt see the comments... You have an earlier system. Alan seems right on the money!
JRB Mr

This thread was discussed between 20/12/2012 and 18/01/2013

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