I need a little help with the refill/drain operation. I look at my radiator and I find the thumb screw but the tip looks solid and the screw def will not turn with finger pressure. Pic below. is mine normal of is it blocked off? thanks Image Unavailable, Please Login
Thats the correct set up, the thumb screw is for venting the radiator. You need to undo it anti-clockwise. Its possibly stuck, so use a small set of grips and go very carefully as you can snap off the small stud This will vent the rad but not the heater matrixes, you need to do this by undoing the top heater hoses slightly untill water drips out. Raising the back of the car helps as this raises the level of the header tank above the heaters. (although they are slightly higher is doesnt remove the natural airlock due to the way the hoses are installed.) You can use pressure filling devices but they are not really necessary Most heaters are never vented properly which is why they clog up and fail so once you have filled the system test that you have good [heat] circulation around the heaters Tony
Thanks for the info Tony! Does the thumb screw come out completely or do you just turn it a few turns and leave it sitting there?
It has a tapered end to the thumb screw so you should only need to undo it a little. Once you get waer bubbling out, redo it back up again. If its stuck, best to undo it completely and smear a little grease on the threads Tony
Helpful Hint: Watch these as they are very easy to over tighten. This brass screw barely needs finger pressure to secure it shut and heating improves the seal. When they get stuck I heard you had to take vise-grips to them when coolant is cold.
Mine came off with virtually the threat of rubber shod pliers. I'm going to put a tiny dab of grease as Tony suggested. Burped the top hose as Tony suggested. Did my first water flush today, will drain (I suppose by loosening the 2 pipes at the rear of the long hoses, seems to be the lowest point of the system) tomorrow and do the second water flush and the the 50/50 on Wednesday. Thanks for the help fellas!
Be careful breaking too many seals on hoses as this can lead to re-sealing problems later on, it depends on how good your hoses are. Also to get all the water out you need to let air in otherwise you create vacuum. Undo the rad vent screw for this.
I have just got a new metal T piece which is at the front of the tunnel hose and T's off for the heater (there is a drip). I have got the car on a 4 poster and the hoses look fine (one is new) and want to get the original T piece out without damaging the (original/old) central hose. Which is the best way to do it ? It has been suggested to remove the clip and then try and squirt WD40 with some gentle flat screwdriver work, then gently twist. Will the WD damage the hose and has anyone got a better idea. I am trying to keep a small job small ! Thanks Nigel.
