rainman69

Hey all,

I got the guts to finally tackle my heater core replacement. I bought the replacement core at AutoZone for 58 bucks. It was made in Mexico, but hey, when I put some H2O in it under a little pressure, there were no leaks, so I can't complain.

I got to the shop and started carefully pulling the dash apart, finding the hardest things being the center vent duct (the big one) and the hard to reach nuts/bolts of the heater/AC box. But I got it all apart, pulled the old core: Harrison datecoded J69...and I could see the spots where it had leaked...I cleaned all the ducting out and installed the new core and buttoned it back up in the reverse of taking it apart.

All in all, it took 6 hours of going slow to keep track of parts, figure out how to take some things apart, and not break things. I just have to go back to the shop tomorrow to install the hoses and the cutoff valve (so there's no heat in the summer) and I'll have heat again!

While I was in there, I noticed my oil pressure gauge was leaking slightly (and onto the radio), so I cleaned up the dribbles and bought a new line and fitting set to replace the leaky one...so, tomorrow is my first experience with compression fittings! I'll let y'all know how it turns out.

It wasn't too bad of a job...YEAH RIGHT! I don't ever want to do it again, but I will if I must. Just not soon, please! :smash:

Bob Elwood

I have had my core bypassed for 2 years now. You are giving me the courage to take it on this spring. I also have some great step by step instructions and pics from Juliet. Glad it went well for you :flag :chevy

Alwyn678

I did mine this summer and It was a similar experience......Not much fun but it is sure nice to have heat!! It is cold outside!!!

Warp70

Could someone send me some instructions/pics of the job. I don't have heat, nor do I usually need it, but I want everything in the car to work wether I use it or not. I also need to know what was used to bypass the core during the summer for those of you who have done this. Thanks :) :) :) :)

rainman69

Usually it involves just running one heater hose from the outlet on the block to the inlet on the block (usually one on intake manifold, one on water pump).

R. Bruno

Wow- doesn't sound too bad. Doesn't it feel great when you do something like that and it works out without days of hassles? :cheers:

Juliet

Glad you guys found the photos useful. :)

There are links to them in the '70 Registry links page. It's in the Mechanicals / How-To section. :) Click on the logo below to get to the registry page. ~Juliet

JIM

only 6 hours? when mine goes out will you do it for me? I did mine when I had the motor out and NEVER want to do another. I have a friend who is a mechanic and he will not even quote heater cores on Corvettes, and also told me when Corvettes are built on the assembly line the first part is the heater core and everthing else is put around it.

rainman69

Spent some time today routing the new heater hoses and making other minor repairs. The hose routing is interesting, as my fuel inlet setup denies using the heater boss on the passenger side of the intake manifold, so I routed from the drivers side, around back of the engine (with a shutoff valve in there too) to the core (5/8" hose). Then I routed the heater return (3/4" hose) in the stock location and to the water pump.

One of the repairs was replacing the oil pressure line from the boss on the block to the gauge, mine had developed a leak sometime in the last 32 years, and so I replaced it. Turns out the reason for the leak was that the compression fitting at the gauge never sealed right originally...well, now it's sealed. No more oil on my radio.

The next fix was rerouting the original antenna cable from its behind the dash location to my custom mounted cd-player stereo in the back. Now I have AM/FM/CD...with four speakers (Alpines all around, 4x6 two-way in stock locations in the kick panels, and 6x9 in boxes in the back)...sounds great.

And finally, was replacing my clock...except, I really don't feel the need for a clock in my Vette...so, I pulled it out and built a custom mounting bracket to mount an Autometer A/F Ratio Gauge in its place. Amazingly, it's the same diameter once you remove the silver bezel from the gauge...and since it's the black Sport-Comp series, it looks "sort-of" stock in there...I'll get a picture, it's definitely a cool mod.

Ahh...it's been a good productive weekend. :smash: