Sandersen511

I have a 99 z28, and my coolant is very dirty with a small amount of rust on the pressure cap. I just want to drain whats in there and put new coolant in, but I'm not sure exactly how to do it and if its possible to do it without lifting my car at all. If necessary, I'm very small and can fit my whole body completely under my car, and I was able to do an oil change a couple weeks ago without any lifting. The only drain pan I have which i will be using if possible for the draining coolant just barely fits under the oil drain plug. I'm new at doing minor maintenance things like this myself, if you can't tell. Flushing the system sounds a little too intimidating for now, so I just want to do a drain and fill. I'm taking a few auto classes and will be able to do a full pressure test and flush in a few weeks, but in the meantime I'm worried about damaging my somewhat new water pump. Any step by step instructions would be greatly appreciated. Thanks!

Injuneer

You can download a copy of the 1999 factory shop manual here:

LINK: 4TH GEN SERVICE MANUALS; 82-02 PARTS DIAG; 99-02 WIRING DIAG - Firebird Nation

Good reference for newbie or an experienced mechanic.

Drain and refill procedure for LS1 V8 is shown in Volume 2, Part 1 of 2, page 6-599

Standard procedure, nothing special like the reverse flow cooled LT1 - In a nutshell:

-park vehicle on level surface
-open radiator cap partially until pressure is relieved, than remove
-open radiator drain valve at bottom of radiator
-remove engine block coolant drain plugs
-allow system to drain completely.

Flush as required:
-close radiator drain valve
-install block drain plugs
-add water to fill system
-run engine until t'stat opens
-stop engine, drain, repeat as required until system flows clean
-clean reservoir

Fill:
-fill radiator with 50/50 mix to bottom of fill neck
-fill reservoir to "FULL HOT" mark
-install reservoir cap
-with radiator cap off, run engine to normal operating temp
-with engine idling, add coolant mix to bottom of fill neck
-install pressure cap
-check system for leaks