Hope this is a quick one. I'm looking for a recommendation for a pressure tester kit that fits an 04 radiator. I was able to test the cap (held at 18 psi) but the attachment to the radiator won't fit. It's the right size diameter but won't sit deep enough because the bottom part where my thumb is too wide for the inside opening of the radiator (the wider gasket at the bottom is the right diameter, it's smaller part that's too big). I've already ordered the replacement parts for the coolant thermostat housing because most of the dried coolant is showing across the top of the engine (air duct, etc.). Feels like a safe guess, not very expensive and will need to be done at some point anyway. I checked the head gasket, it's pretty much brand new and this started before I replaced that. Also, the oil looks perfect, so I don't think it's a bigger issue. Thanks.