I've removed and replaced hoses around the intake (secondary coolant).

Noticed that turning them on the male copnnector helps loosen the freeze put on them by the heat the years. Had to tear one off to get it removed.

Question is: even though new factory hoses fit, what can I apply to the inner hose to make them slip on easier? (especially larger one.) They want to go on about half-way, not fully, being to dry or tight. Takes a mighty force.