I still have a temporary pressure gauge plumbed in at the coolant expansion tank from when I was sorting out leaks at the coolant flange (since fixed). It would read anywhere between 5 to 17 psi depending onhow hot the engine is. A few days ago, I noticed no pressure registering on the gauge. and some wetness from the expansion tank. A closer inspection revealed a pinhole leak at the top of the expansion tank about 1/2" from the cap. Is this a usual failure of the expansion tank? What's it made of? Polyethelene or Polypropelene? I'll have to order a new one, good they are only about $13. I think I may plumb the coolant pressure gauge permanently into the dash. Anyone done that?
if its on the tank itself why not use a soldering iron or heat gun?
if its on the tank itself why not use a soldering iron or heat gun?
I thought about doing that to save a few bucks but it seems the plastic is old and stressed from too many expansion / contraction cycles and new leaks may develop. What I don't want is the tank coming apart resulting in total coolant loss and an overheated engine.
if you fix it and it still leaks, you are not out any money. if it leaks again or yo ucant fix it, throw it away and get another one.
I patched it just to see if it'll work but I am still going to replace the expansion tank. I sanded the pinhole then wiped clean with alcohol, apllied 5 min JB weld over it. the JB weld did not want to stick to the plastic and I had to rub it it before it'll stick. after it cured I applied some Loctie gasket sealant over the epoxy. I'll take it for a drive later and see it it'll hold pressure.