Hello i have a question that some of you might be able to answer.

I have a couple customers 99 foresters that i just installed JDM 2.0 SOHC engines.  After test driving them and getting them up to temp i noticed that the radiator hoses have a decent amount of pressure in them. You can still squeeze the hose but you cant squeeze it enough to get the sides of the hose to touch.  On my 99 outback with a phase 1 2.2 i can drive it the same distance/temp and the hose has almost no pressure in it when warmed up.

Ive never paid much attention to hose pressure unless there's an overheating issue.

Just wondering what the difference might be

 

 

How much air is in the system.

 

not very much.  the engines were just installed.

After they burp their air thats about a cup or so of anti freeze to top off.

it shouldn't be any more than 13 or so psi since the radiator cap should release into the bottle.  check if there's a blockage on the cap?  I've seen caps that have the rubber part expand over time and jam the relief valve mechanism from opening.

The 99 Forester 2.5 call for a 16 PSI cap.

The 99 Legacy 2.2 calls for a 13 PSI cap.

The cooling system should be under pressure to raise the boiling point of the coolant.