Need Help with Diagnosis Please!!!

[mechanicaldj]

Overall I am extremely pleased with how far I've come with getting Hot Rod running. For the first time HR is running very smooth, with more horse power and only a slight smell of coolant. As a matter of fact I got Hot Rod on interstate today, up to 75 mph, and not a hitch, skip or hesitation. Now the last issue. I'm still losing coolant. I've checked the head, the TB and lower hose to find nothing. On one occassion I found coolant on the driver's side just over the battery on the bottom side of the hood. I can't find a pin hole or anything else. There's no oil in the coolant and no coolant in the oil. Only thing I can imagine is a pin hole
somewhere. Is there any way to test the coolant system to find a leak?

has the coolant bypass hose at the front of the motor been replaced lately???

[BigWheel]

has the coolant bypass hose at the front of the motor been replaced lately???

It has. I talked to a guy today though that said he was having a similar problem with his several years ago and gave me an idea to check out. He said the resevoir had a pin hole in the bottom of it in the seam due to age. He couldn't find a leak but whenever he filled the radiator and the engine got hot he would always smell coolant. So he filled the resevoir with coolant and sure enough he found the leak. Replace the resevoir and no more problem. I'm going to do that in the next day or two and see what happens.