The pink fluid could be the Coolant if you have the GM long life coolant, which many Subs that age probably have. If that is what the problem is, you may have the intake manifold problem commonly reported here. Mine was covered under warranty, but would have cost around $750.00.
The garage did a leak test to nail mine down. There are lots of postings here though on the subject if you want to diagnose yourself, but don't wait. Once the coolant starts leaking inward, instead of just outward, it does all kinds of damage to the engine.
'99 Suburban SLT