Heres the latest on my use of Steel Seal. Done about 2k since I put the stuff in, including a Holiday in Scotland, a weekend in Wales, and half a dozen trips to the peaks and South Yorkshire. Not lost a drop of coolant, and the temp gauge hasn't budged

. I still carry 5 litres of coolant in the back, just in case, but so far so good.
Coolant change. Here's my method:Take bottom hose off, radiator cap and expansion bottle cap. Flush system with cold water until it runs clear. Under the passenger seat is a 3/4 in rubber pipe, clipped to the side of the engine bay above the wheel arch. Release this. IN the end is a bung with a pipe clip. Leave this as it is for now.
To bleed: Replace bottom hose. With both caps off, fill radiator and expansion tank with fresh coolant until full. Start engine, and while its running, gently squeeze the hoses. You will get some big bubbles coming out of the radiator and expansion bottle, and the level of coolant will start to fall. Keep topping the rad up and continue to squeeze the hoses gently to push the coolant round, and release any air in the system. Keep checking the expansion bottle and top up as the level drops.
Keep going with the above until the level in the rad stops dropping.Carefully (wear gloves!) remove the bung from the hose mentioned in the first paragraph. There will be hot water in this pipe so point it away from you. There will be a coughing/burping noise and there will be spurts of coolant from the pipe. You might need some help here. Get another to keep an eye on the coolant level in the rad, and gently squeeze the pipes. The level will drop so the other will need to top it up. Eventually the coughing from the pipe will stop, and a steady stream of coolant will start to pour from the pipe. Hold the pipe up and away from yourself and get the other to turn of the engine.
Carefully replace the bung, and clip. Make sure the rad is full and the level in the expansion tank is correct. Put the rad cap back on. The engine should be getting warm now. Keep an eye on the expansion tank, keep squeezing the hoses and watch the tank for bubbles, when they stop, all is good, nearly done.
By now the engine should be at operating temperature, and the fan may have cut in during this process, this is fine. Check the coolant level in the expansion tank, if it has dropped, top it up to the correct level and replace the cap. Restart the engine and take a look at the temerature gauge, it should be at its normal position, about a 3rd of the way up. If it is, all is good. Take your bongo for a gentle run round the block, keep a constant eye on the temp gauge. If the gauge stays constant and doesn't move, well done, you have succesfully bled the system and your bongo should be safe to drive normally. If while you are driving the gauge starts to rise, or begins to rise and fall, there could be air in the system. Pull over, or get home asap. Park up, and with the engine running check the gauge. If it continues to rise, switch off, leave to cool, and go through the bleeding system again.
DISCLAIMER! This is how I did it and it worked for me. Please note that I cannot be held responsible if this process doesn't work for you. I tried to use the info sheets on here from other members, but I got confused with all the various rev ranges and timings that they mentioned. It seemed a little pointless to me, but I'm not a mechanic so what do I know!
I apologise if I have not put my info in the right topic heading, I'm quite sure it should be elsewhere, but I don;t know how to link this post to another topic heading.