Help! 1991 heater core replacement

[LucyC]

My heater core went out on my 1991 vette, I've heard horror stories on replaceing them on your own, any advice?... any threads on a how to for this kind of job?

 

[jonszr1]

well i hate to tell ya but its an 8 hr job . i would invest in a factory service manual or maybe someone close to you has one you can borrow . you must remove the whole dash top and a bunch of other stuff .really isnt hard just a ton of stuff to remove and put back .

 

[LucyC]

Thanks, I have purchased the service manual, but for the mean time it's been disconnected and plugged....

 

[dugr]

You didn't say that the heater core was leaking. If it is not leaking you may want to try backflushing the heater core. When I purchased my '94, in 2001, it had 83,000 miles on it. It was December, in Ohio, and I was not getting much heat out of the unit. I purchased the correct size hoses in lengths long enough to come over the fenders and into a large bucket. I connected a water hose to one hose and ran water through the heater core and into the bucket until it filled. Emptied the bucket and connected the water hose to the other hose and repeated the above until the water ran clear. I never had any more heat problems.

 

[boomdriver]

I was going to get some flush agent in and recirculate that for a few, then blow it out with water hose adaptor and reconnect. My heat was mediocre at best last winter.

 

[MBDiagMan]

dugr offers a better suggestion than chemical flushing. Back flushing the HEATER CORE ONLY is a very good thing to do in the case of restricted flow. A leaking core is a different situation.

To back flush the heater core, simply remove both lines and rig a garden hose to flow BACKWARDS through the heater core.

If flow is restricted this is the only thing that has a chance of clearing it out. Chemicals won't work because they can't flow through it to do anything.