Jim- your reply is right on. It does howl, and has gotten low at times that
there is undoubtably air in the system.
There are two hoses that go into the canister.
Which one is the low pressure one, the one more towards the
front or toward the rear?
It still looks like it is seeping out of the top when it is "frothing"
Could the top gasket be bad enough to allow this, or is this
because air is forcing it out?