Checking Radiator water level - Serpentine.

[Chocaholic]

I'm just recovering financially from a leak in the radiator. I had checked the water level in the expansion tank, which seemed OK. Problem was that there was nothing in the radiator. For peace of mind in the future, should I check the water level via the swirl tank? If so, how do I undo the brass screw on top of it?

[bigdods]

Check the water level in the swirl tank, but also undo the bleed screw on the rad to check its full and no air in the system.

I have a crowbar with a flat end the fits the swirl pot perfectly. Not sure how others do it. On my 450 serp the radiator bleed screw is at the top of the rad on the offside.

edit to correct my stupid mistakes!

Edited by bigdods on Sunday 15th July 21:27

[AlexanderV8]

Chocaholic said:

I'm just recovering financially from a leak in the radiator. I had checked the water level in the expansion tank, which seemed OK. Problem was that there was nothing in the radiator. For peace of mind in the future, should I check the water level via the swirl tank? If so, how do I undo the brass screw on top of it?

You need to check & fill the system from the swirl tank but first you need to ensure there is no air in the system (as happens when there is a leak somewhere). It is explained in the handbook (if you got one with the car). The way I do it is:
1). Ensure coolant is cold and remove expansion tank cap.
2). Turn heater control to hot.
3). Fill expansion tank with coolant to about half way up.
4). Remove brass screw on top of swirl tank. Mine was stuck rigid when I first got the car and no matter how much leverage I tried applying, it wasn't going to shift before I would have distorted the can, so I (very carefully )applied a blowtorch to it (avoiding any hoses or plastic parts etc. with heat shields). It didn't take long to break the seal and then it unscrewed easily by inserting the tip of a large flat-bladed screwdriver sideways and applying leverage. It always opens easily now every time.
5). Fill swirl pot to the top with coolant.
6). Undo bleed plug on top of radiator (might be on either side!). See what comes out! If air comes out, wait until only coolant flows with no air. When all air has gone, retighten radiator bleed plug.
7). Refill swirl tank with coolant to the top. (The level will have dropped as the coolant comes out of the radiator bleed).
8). Replace swirl tank brass screw.

Basically, that is the process I use. You should then run the engine until the fans kick in, wait for it to cool and then repeat the process. This is to try & purge the system of any air that may have been trapped in the heater matrix etc.

If the car susequently dumps some coolant on the garage floor, don't worry, it is it's way of naturally finding it's own level in the expansion tank. Mine runs only about an inch fron the bottom with no problems. Excess coolant is evacuated via the blue expansion tank cap.

Edited by AlexanderV8 on Sunday 15th July 18:34

[over_the_hill]

To undo the brass screw I used to use a bolster chisel sideways on - fitted perfectly into the slot - then put an adjustable spanner across the chisel blade so I had two handles to twist on - the chisel and spanner. However, I have since replaced it with a Steve Heath cap which uses an Alan Key.

[Tekno]

Hi team.

What’s the level the coolant should be at at the Swirl Pot? Can’t see this mentioned anywhere, hence the holy thread resurrection - Batman.

[Sir Paolo]

It seems to vary a bit from car to car, but is usually about 1/3rd to 1/2 full.
It may take a while to settle, but if you keep topping up while it does so, you’ll think it’s loosing water

[Sir Paolo]

Apologies- I misread the query- the swirl pot should be completely full, at least to the bottom of the threads.

I was referring to the expansion tank 🙄

[Tekno]

Sir Paolo said:

Apologies- I misread the query- the swirl pot should be completely full, at least to the bottom of the threads.

I was referring to the expansion tank ??

Excellent - thanks. It will become apparent once I open it.