Chevrolet Repair: 1998 S-10 blazer heater core, heater core, brake booster

Question
I am in the process of replacing my heater core on my s-10 4wd blazer.  I removed the entire dash to expose the heater core housing.  I removed one bolt from the lower right hand corner inside the passenger compartment.  I removed three bolts from around the heater core hoses in the engine compartment and two nuts located behind the right front tire behind the wheel well.  The heater core is totally lose on the left side but still attached on the upper right hand side when attempting to pull the housing free from the fire wall.  Any idea where addition nuts or bolt are located?

Answer
Hi John,

These bolts are sometimes hard to access.  They will be behind hoses, sensors, and even the weatherstrip that seals water from the engine compartment when the hood is down.  What seems high in the truck is actually lower under the hood.  Look all along the firewall...both sides.  Look behind the brake booster.  They can be bad.  

That is a big job.  Good luck!

C J S