its a fullsize 1990 GMC jimmy. i know that the core is behind the BIG BLACK box thing behind the glove compartment, but HOW does this come off? its got about 4 or 5 little flush mounted pins holding this big box to the inside of the firewall.....HOW DOES IT COME OFF? i need to drive it in about 2 hours!!!! thanks:usa:

alls i knows is that them flush mounted pins in your engine compartment, they are bolts, and the nuts are inside. use a 1/4 inch size ratchet for easier access (little tiny ratchet)
i think theres about 5 of them, of course remember to take hoses off of core from under hood.
a good trick is to just throw 2 bolts back on by hand till you have more time to fix it.
the big black box thing comes out from inside, its not to bad, grab a light for under there so you can see.

jsut fixed it. thanks for the help. i found a GREAT tech write up on coloradok5.com

whats the addy of the place that you got the tech post from?

ummm......go to www. coloradok5.com and on the homepage click on " technical" and its towards the bottom.....hope that helps!

http://www.coloradok5.com/heatercore.shtml

hey thanks bro, that will be a good link to keep handy, its been awhile since i had to do a heater core :p

so how did your heater core work out? :D

The replacement is not a pep boys special is it? I tried using those and went through 3 in a year. Buy a quality core replacement.

Charlo

Originally posted by dallas
jsut fixed it. thanks for the help. i found a GREAT tech write up on coloradok5.com
Your Welcome :)