Re: Cracked Exhaust Manifolds, Block?
I disagree with bondo on this. I see to many locked up circulating pumps every spring, while air does not freeze,as the water weeps out of the casting it accelerates corrosion(rust). and water will bleed out of cast iron for months. every spring, especially after a few rare 9*F days, I replace 4 or 5 motors maybe 10 sets of manifold/risers and the odd assortment of seawater pumps and oil coolers as well as saltwater washdown pumps and such. another issue is some of the EFI motors have water cooled vapor seperators that will freeze as well and are hard to drain. <br /> so after doing everything and starting the fogging procedure I shut it down, drain the block, hook up about 5-8 gallons of a product like frost ban 2000 and start it back up. this will refill the block,manifolds ,risers,water passages in various coolers and vapor seperators and most importantly rob the block of rust forming oxygen. plus the AF mix has corrosion inhibitors and it keeps the various seals and such wet.<br /> so while no air itself does not freeze it does not protect either and accelerates rust.<br /> add certain minerals and it rusts rapidly.<br /> I use my gearcase pressue tester to test the block assy's. pump it up to 10-15psi and let it sit, if it holds 30 min or so at whatever pressure I left it at its ok.<br /> to set up the test block off any hoses going to the manifold/risers. remove the seawater inlet hose at the Ttat housing and apply pressure there. if it holds the block assy is water tight, if it does not its time to try to listen for air hissing and then a teardown.
