Heater Core Repair

The weather here is getting cold, and although the heater is hooked up, the car wasn’t putting out any significant heat to the defroster or cabin.  I took it for a drive a few days ago, and noticed this on the garage floor:

Maybe it’s a loose hose connection inside the engine compartment?

looks damp, but…looking inside the car…

The core is leaking…no question about it.

I really hate plumbing and liquids in cars.  I always seem to make a mess no matter how careful I am.  I was determined to NOT make a mess this time, so I took some precautions.  It ended up working out really well!

First step: drain the radiator.  I threaded a piece of vinyl hose down to the bottom of the radiator, and used my mityvac to start a siphon into a trash can.

When I replaced the heater hoses this summer, it made a mess even though I was sure I had drained all the coolant out.  I decide to see if I could get more coolant out of the heater core before disconnected the hoses there.

Once it had drained below the level of the water pump, I disconnected the heater hose there.

…and clipped the corner off of a plastic bag so I could blow through it without getting dirt in my mouth.

That forced most of the liquid out of the heater core and into the lower hose…which drained back into the engine block, and was siphoned out with the rest of the coolant in the radiator.  After the coolant was finished draining, I removed the heater hoses from the heater core pipes, and…no mess.  Nothing came out when I disconnected the hoses.

To be extra sure, I put the vinyl hose into the lower pipe, and used the mityvac to suction out any coolant I could get.  I didn’t end up getting anything out, which means forcing the coolant out worked great!

I knew the next step would involve tipping the heater core out to get the pipes out from the firewall holes, and I didn’t want to spill anything, so I rolled up some paper towels and threaded them into the heater core pipes to at least slow down anything that was going to come out.

The next step is taking off the 5 speed nuts holding the heater box onto the firewall.  Good news/bad news, there were only two nuts installed on the car, so that went a lot easier than it should have.

Moving to the interior, I put down a big sheet of plastic over the carpet, and put an old towel on top of that to soak up any spills.

Getting the housing out was not simple.  I did not take out the glovebox, I did not take out the console, I did not disassemble the center dash section.  All three of these would have made the job easier, but so far it isn’t 100% necessary.  I may need to do some or all of those things for reassembly, but I don’t know yet.

Things that can and should be disconnected:
– The fan wiring plug on top of the housing should be unplugged
– The plastic diverter piece that sits in the center of the transmission tunnel
– The climate control cables that are attached to the housing.

A tiny 5/16″ ratchet box wrench was the only way to get the mounting screws out of the plastic diverter housing.  It was difficult even with that tool.  There are several screws that need to be removed.

I didn’t disconnect the cables entirely, mostly because I couldn’t get the circular cable end off of the pegs they were on.  I decided I’d be able to get to them easier after it was out from under the dashboard.  I did disconnect the mounting brackets that I could get to.

Once those cables were loosened, I was able to pull the housing out to the passenger side.  This left the core still in the firewall half of the housing, which means it unsnapped itself from the brackets that hold it into the passenger half of the housing.  I’ll worry about that later.  I was not able to get the housing completely off because it is still attached to the cables…but I have a better shot at removing them now.

I was able to get the heater core out after the housing was out of the way.  Amazingly, I did not spill any coolant getting it out.  That’s a huge win in my book as I didn’t want to make a mess of the carpet or the garage floor.

It does not say “Harrison” on it, so I do not think it is original.  Because it’s a replacement, I’m not sure it’s worth having it re-cored.  Not so much for originality, but just design.  An original recore should work and fit better than a cheap modern reproduction.

Not surprisingly, there was a huge mouse nest in the housing, which explains why there wasn’t any significant heat coming out.  No airflow!

I’ll clean this out and paint it to prevent further damage before I put it all back together.

Stay tuned…



Dummy Cigarette Lighter Element

When I had the center of the dash apart to fix the heater controls, I also replaced the cigarette lighter socket.  I don’t smoke, but I wanted the socket to work so I could charge my phone, or run a GPS.

The lighter element was rusted into the old socket, so when I pulled on the chrome knob, it pulled off of the rest of the lighter.  I didn’t want to put the old rusty element in my nice new lighter socket, so I made a dummy one to hold the chrome knob so nothing looked like it was missing.  I created a 3-D printer design for this, which I uploaded to Thingiverse.


The final photo shows it in the dash, and the flash managed to highlight all of the dirt and scratches on the dashboard.  It looks better in person.

Paint Fix

This car has been repainted several times from what I can tell.  The most recent paint is some version of Butternut Yellow, with black stripes, and black taillight panel.  The strange thing about it is the black stripes are done fairly well, but the overall finish is terrible.  It looked like someone had gone back and fogged some muddy dirty version of the yellow over the base yellow.  This didn’t make sense, because that would have covered up the black stripes.  The driver’s side fender was the worst offender, there were big runs and puddles on the top, pooling into the middle of the fender.

I like driving this car, and I actually kind of liked that the paint was so-so because then I didn’t have to be worried about it getting scratched in a parking lot.  But still…it would be nice if it was at least a little nicer looking.

I was discussing this with someone at the Castle car show, who suggested the dull finish was really just a very badly applied clearcoat.  Bingo…that would explain how it could be applied after the black stripes were added.  There were some spots where the yellow showed through because of poor surface prep or something, and it was obvious that a muddy clear had been sprayed over a lot of the car.  In some spots it was very thick, but in other spots it was barely fogged on.

I decided to see what would happen with some elbow grease and some aggressive paste wax.  Turns out…it shines up pretty good if you really hit it hard.  It’s tough taking a picture to show how shiny something is, but here’s my attempt.  The front part of the fender has about 30 minutes of hard scrubbing with the paste wax in a 6″x6″ area, while the front header panel is the original finish.

This needed some power to make the job go faster, so I got some 1000 and 1500 grit foam sanding blocks, and started wet sanding.

After about 3 hours of working on the top of the fender, most of the clear was removed.  There’s still some remnants of the puddles and runs that were there, but I didn’t want to sand through the paint, so I stopped for now.

One nice thing was that several black marks in the paint disappeared.  I had assumed they were chips that went down to the blue paint under the yellow, but it was actually just pieces of dirt stuck in the clear.

I got a polisher and some polishing compound, and went over the area I had wet sanded, then put some wax on it.  Not perfect by any means, but a lot better looking at least.  This is going to be a long-term project, I’ll keep doing sections until I work my way all around the car.

Castle Car Show 2021

Part of the motivation for putting the heater controls back together was so that we could attend the Castle in the Clouds car show today in Moultonborough.  We made it to the show with no drama, and lots of people stopped by to share their Camaro stories.


Fixing the Defrost Lever: Part 2

Get the repair kit they said.  It’ll be great they said.

The kit consists of a new arm, and some screws to attach joints that were originally staked.  The new arm is much beefier than the original one, so it looks like a good upgrade.

The disassembly process is pretty simple.  The first step is grinding off the two staked pegs holding the pivot end plate.

The third point is the pivot at the end of the defroster lever.  Once that is ground off, the old lever can be removed.

At this point, the instructions say to drill and tap the two pegs holding the pivot end plate.  The supplied screws are 4-40, but it’s up to you to find the appropriate drill and tap.  It turns out that is harder than it sounds.  I hit several large box stores, none of them had anything that small.  I finally broke down and hit eBay, and ordered a Du-Bro drill and tap set, intended for model hobbies.

It was shipped and supposed to arrive in the mail on Friday, so I figured I’d be able to work on it for the weekend.  Wednesday it disappeared off the tracking, so on Friday I hit a real hardware store and found a 4-40 tap and the correct size drill to go with it.  I drilled and tapped a test hole, but it turned out that the tap was UNC, and the screws were UNF.  Friday night the package was on the tracking again scheduled for Monday.

When it arrived, it turned out to also be a coarse-thread tap.  I decided the universe was trying to tell me something, and I dug up some 4-40 coarse thread screws and used those instead of the supplied ones.

Drilling the holes.  The tape marks the correct depth for the hole.

Tapping the holes

Once past that hurdle it was a matter of putting the screws in with some locktite and reassembling it.

The hole in the end of the new lever also needed to be tapped so it can be reconnected with a screw.

Back together again…mostly.  Each cable has a loop on the end that fits on a peg on one of the levers.  The loop is supposed to be secured by a push nut, which looks like a washer with cuts radiating from the center hole that grip the peg.

I managed to lose or break all of the original three push nuts, plus a fourth one that came with the repair kit.  Someday I’ll buy some and install them, but it looks like it will work for now.  Tip: buy extras when you buy your kit.

This does actually work, and the defroster diverter valve does open and close as you slide the defrost lever, but…it’s a fix that doesn’t really show up well in pictures.  Looks about the same as when I started!

Fixing the Defrost Lever

My father had a 68 Firebird when I was growing up.  (The dash is virtually identical to a 68 Camaro.)  At some point, the defroster lever broke, like pretty much all of them do eventually.  I remember hitting a local junkyard and pulling a replacement climate control panel from a car there, and swapping it in.  Unsurprisingly, a few years later, the defrost lever in the replacement one broke also.  I took it apart and drilled a series of holes along the side of the crack and sewed it back together with some wire, and slathered the whole thing with epoxy.  That lasted another few years before it broke again.

Fast forward to today, and…the defrost lever in our Camaro is broken.  As the control panel is at the top of the dash, everything below it has to come out to get enough room to remove it.  The aftermarket gauges, the ashtray, the radio, and the front woodgrain bezel all need to be removed.

I ordered a replacement lever (OEM brand) which is still cast metal, but it is definitely beefier than the original one.

After removing the control panel, it was a bit ripe on the top side where the mice had used it for part of their travels.

I didn’t figure it out at the time, but if you unplug the blower fan wiring (the plug at the right of the picture above) and pull the light socket out from the RH side, the whole unit can swing down between the dash and the gas pedal with the cables still attached.

I decided the first step was to give it a bath in the ultrasonic cleaner.

After a few cycles through the cleaner and a little scrubbing with a nylon bristle brush, it came out looking better.

Next step is removing the old lever.  Stay tuned…

Refurbishing the vent ball assemblies

I don’t know why exactly, but the astro-ventilation assemblies always fascinated me.  They really seem like an important part of the dash design, and not just an afterthought.

The ones in the car had seen better days, they look like they are original pieces.  The housing was in very good shape, the chrome on the bezel was all intact and smooth, but the felt seals had turned to dust a long time ago.  The chrome on the ball parts was in pretty bad shape, probably about half of it had worn off entirely.  I purchased new aftermarket balls, and a felt seal kit.  The new pieces were not exactly like the old ones.  Most notably, the new ones had a distinct separation line around them, while the originals were all smooth.

The first step is disassembling and removing the housings.  There are two screws on the bezel, one at 12 o’clock, and another one at 6.  The bottom screw goes directly into the dash metal, but the top one goes into a short curved metal bracket that pinches against the back of the dashboard.  You don’t technically need to take the top screw out all the way, just loosen it up a lot until the bracket is loose.  If you take the screw all the way out, make sure you don’t lose track of the bracket.  The two screws are different length, the short one goes on the bottom, and the longer one goes in the top hole.

The control knob next to the housing unscrews, leaving a threaded rod.  This is the same as the door lock knob if you need to replace it.

The natural thing to do is to pull the housing out of the dash, but that leaves the threaded rod stuck in its hole in the dash, which doesn’t allow it to come out.  The trick is to pull it out just far enough that you can get the bottom of the housing to push back through the dash opening.  Once it’s there, turn the housing 90*, which will pull the threaded rod out of its hole, then you can feed the whole assembly out through the front.

There is a short plastic oval flexible tube that connects the back of the assembly to the cowl vent.  This may fall out as you take the vent assembly out, as there’s no fasteners on it,  it’s just held in place by the vent assembly.

Once the assemblies are out, mark them left and right so you don’t get them mixed up.  You can identify which goes on what side by the threaded rod lever is on.  3939616 is the RH one, 3939615 is the LH one.

There are three tabs on the chrome bezel that fit over corresponding bumps on the black plastic back half.  To disassemble these, you need to carefully separate the two halves, and gently pry up on the tabs to get them past the bumps.

In my case, the flapper valve was in great shape, and did not need any repair.  You may need to disassemble this part and add new rubber seals.

I used Permatex upholstery adhesive to attach the new felt pieces.  This is the same glue I used on the headliner.  It’s contact cement, which means you put it on both pieces, let it dry a little while, then stick the pieces together.  It’s very sticky, and you only get one shot at putting the parts together, as it’s very difficult to separate them.

I sprayed the adhesive on the felt pieces, then sprayed a bunch of it into a baggie and used a q-tip to paint the adhesive on the housing surfaces.  (Originally I had planned to spray the housing piece also, which explains the blue tape.  I decided to try the q-tip, and that worked out much better.  No tape required.)  After 5 minutes I gave everything a second coat (per label instructions) and let it sit for about 10 minutes.

Once the glue had set up and was tacky, I carefully worked the felt strips around the housing mount surface, and trimmed off the excess when I got back to the start again.

I let this sit and dry for a day (per label instructions) before doing the final assembly.

On the black half of the housing, I used scissors to trim the felt flush with the edge of the plastic.  On the chrome half, there wasn’t a good way to trim off the excess, so I just left it.  It might be a good idea to trim these to the correct width before gluing them on, but it seemed to work with only the other half trimmed, so…maybe that’s not necessary.

Reassembling the housing is straightforward, put the ball in, and carefully press the two halves together until the tabs engage the bumps.  Make sure everything works smoothly before continuing.

Putting the housings back in the dash is the toughest part of the job.

Good news: I think I have a promising second career as a contortionist.

For the driver’s side, there’s zero room to get your hand up there with the parking brake assembly in place. It can be done without removing the parking brake! The surprisingly successful installation approach was to turn it 90* and feed the assembly from the front all the way through the opening so the bottom of the bezel was completely behind the dash, then  rotate it upright again and tip the top edge back out through the opening while feeding the threaded rod through the ferrule.

The same process works on the other side.  In this picture, the bottom edge of the housing is inside the dash, the top edge is out, and the threaded rod has been fed through its hole.

Continue pulling the assembly out until the bottom edge comes out. The oval flex tube joint goes on next, then align and tighten the screws. For the top screw, thread it through the bezel and into the metal clip, but leave it loose. Once you get it into place, use the screw to rotate the clip until it’s facing the right way (longer curved end up), then pull down on the bezel to pinch the clip in place while you tighten the screw.


Door Glass Fix – Part 2

Got a new top window guide, installed new weatherstrip on the door, and put it back together again.  I ended up cutting a small piece of radiator hose to replace the rubber stop block in the bottom of the channel.

Before and after:

Door Glass Fix – Part 1

The window on the driver’s side door hasn’t rolled down all the way since we got the car.  There was about 3″ showing when it was as far down as it was going to go.  After the mouse nest fiasco, I assumed it had something to do with that.  I was right.

Working with the door glass on these cars is awful.  I found an excellent series of videos about doing the job, that at least showed it could be done, and lots of good tips on how to do it in the easiest way possible.

Once I got the glass out, I discovered that the front guide track was corroded at the bottom, and still had the remnants of the mouse nest that I had removed from the door when we first owned the car.

A lengthy session with a wire brush followed, and the guide track was clear enough to fit over the window roller again.

I also found out that there were some missing parts.  The guide is supposed to have a rubber block at the bottom to act as a stop.  I’m guessing the mice ate it.

There are also supposed to be two guide blocks on the inside top of the door.  The rear one is missing.

While the glass was out, I got to play “How many times has this door been painted”, and I counted at least 3 different colors, in addition to the factory color.


Winter Project 3: Distributor

The previous owner had installed an HEI distributor.  These are great units, but the install left a lot to be desired.  As I discovered when I was first trying to get the car running reliably, the wiring was incorrect, and was not supplying a full 12V to the HEI.  This resulted in it running really poorly, it would backfire and pop at pretty much anything above 1200 RPM.

My theory is that someone installed the engine and transmission, couldn’t get it running right, and never got the car on the road with the new setup.  They parked it until we bought the car.

Once the power was sorted out, the car ran much better, but it still wasn’t great.  I bought a new module for the HEI, expecting that might be the problem.  When I opened up the distributor to install the new module, I discovered that the whole distributor was in pretty sad shape.  The weights were covered in rust, the posts and the holes were very worn, and they did not move freely.  That was causing inconsistent timing, which didn’t allow the engine to run as smoothly as it could.

After looking at what it would cost in parts to rebuild the existing distributor, I ended up just buying an entirely new Accel unit for less money.

I got the 59107 distributor, which comes complete with everything…except the coil.  Oops.  I transferred the coil over from the old distributor, and will use that until I get a new one.

The challenge with changing the distributor is that it’s a little bit of a gamble on where the timing is set before you can get the engine running so you can check it with a timing light.  It doesn’t have to be exactly on the perfect position, but it needs to be at least in the general area.

As it happened, I put the new distributor in one tooth different than the old one.  It still works fine, and I was able to set the timing properly, but the vacuum can is aimed differently than the old one.  Not a big deal though.