Premise: How to check engine vacuum hoses<br>Check each hose for bulges and swelling. If a hose feels soft or spongy when you touch it, this can indicate damage caused by your car's oil. [substeps] A swollen hose that is cracked and hard is often caused by heat damage.
Hypothesis: A swollen hose that is soft or spongy when you touch it can indicate damage caused by your car's radiator.