I just buy the 2 jugs of full concentrate because its $2 more than 50/50 and I get twice as much after I add water. If you don't have pressure, then you might have air trapped in the system. I would just check it every time before you drive and make sure the overflow is filled. Most vehicles I have had, I can run half locked no issue. On my DD, it will spew out within 5 mins if it isn't 100% locked.I'm not sure where I got my wires crossed but after much tweaking I have the antifreeze at -37 degrees. Should have used one jug of concentrate and one 50/50.
You are supposed to pull it out and see if the holes in the stem are filled with fluid or dry. Its not like an oil dipstick.Okay was out today 28 degrees Celsius (82.4 Fahrenheit) , AC on pulling my boat and the temp was just under half. Given the previous information in this post, that sounds about right. Overflow is full. BTW, am I the only one that has trouble with the dip stick on the overflow? It is very hard to tell where the level is.