I found the leak on my C70 1999, it was the radiator. RH side (pass. side) where the metal meets the plastic. I took it to Volvo mech. and he told me to replace the radiator. He also told me to try radiator stop-leak but I'm not so sure about that...

Hope that you can find and fix yours.

The no-start problem I can't give any info on. However, I also have a coolant leak on my C70 1999. I'm going to install an engine heater on Tuesday and at the same time try and locate the leak and fix it. I'll get back to you on what I find when I'm under the car.

Good luck Robert! I'll be looking for some video on your YT channel. Just finished watching the V70 and S70 restaurations.

Best of luck from Sweden