Friday, July 29, 2022

Cabin Air / Heat in the PV544


A few years ago when the brake fluid reservoir sprung a leak and I had to fix the resulting mess , I yanked out the heat and fresh air system in the Volvo . It was in the way and the heater core was giving off the sweet molasses smell telling us it was leaking . At that point trying to get things done I cut a plate and caped the firewall opening and called it good . This resulted in no fresh air in the cabin other than from the windows . And the firewall gives off a fair amount of heat too. I needed to do something about that .

Sooooo . . . .

A tin can  . . . yes escargots . . . as in snails in a tin can

 . . on an appropriately confectioned piece of aluminum

Times two . The intake that goes to the left of radiator needs a bit of an angle to it .

There that will do the job . 

Yea it only provides flow when you are moving , but heck its better than nothing .

 Now about the Darth Vader heater box . . . yea that's one half of the mess .


A couple hours going at it with the drill and abrasive wheel gets us this far .

lots of grinding later . . 

Coat with rust neutralizer to eliminate any pin hole rust I missed

Good thing I snagged about half a dozen cans of this stuff when it was on clearance for $1.25 at Wallyworld .

Yea good as new . . . don't look too close or you'll spot the runs I had to sand out and re spray .

Then there was the leaky heater core itself 

 That one took about two dozen tries before I got all the pin holes soldered up not just where the cap meets the top plate but were the individual tubes meet the top plate . I'd get one done and the next one down the line would start leaking too . Never took photos of that process .

The fresh air intake up front next to the radiator was all mangled up from sixty years of life . Yea I forgot to get the "before" photo . Mended the missing parts with JB Weld putty, filed sanded and painted with the same appliance epoxy paint . The hardware cloth screen on the front was a mess too . So I made a pattern out of cardboard .

Copied it in aluminum 

Hole sawed  . . . .

Hole-sawed some more . . 

snipped . . .

Filed . . .

Epoxied some new bronze hardware cloth . The yellow bits come off after a few minutes of curing. They are HDPE from an old kitchen cutting board to get the JB Weld to lay flat and embed in the hardware cloth .

What it was and what is now .

And once installed it wont even be visible . It never had a frame like that from the factory but it was the only way I could come up with to hold the otherwise floppy bug screen in place .

Then there was the blower motor too . See those arms that hold the carbon brushes ? Both  are missing the top hook on the hinge point .

JB Weld to the rescue again . Let it cure about four minutes til its just hard enough to hold together . Peel the tape off and start carving very carefully with an Exacto knife .

Not ideal but it will have to do till I source a new motor .

New rubber bushings

 Almost like I knew WTF I was doing

Looks smart don't it ?

There , not quite good as new but it will do for now

Darth Vader's mask ready to go back in the Volvo .


  1. What we do for old cars... Can a radiator shop source a new heater coil? Can you fab in an equivalent modern heater core to provide heat?

    1. Hi Kevin hope all is well with you.
      I can buy a brand new heater core from VP Autoparts, the go to source of old Volvo parts here in the US . . . for the princely sum of $355 plus shipping.
      But where's the fun in that? I managed to repair the old one for now. I may not put the it in at all. Early December the car goes into hybernation as I wont drive it on salty roads. It would be sacrilege to do so and would kill it in a couple years. And the engine bay puts out enough heat through the firewall to be comfortable enough for any driving up til then. What I really need is better venting. The monkey rigged passive conduit I put in is ok when moving, but come to a stop light and you start dripping. So I may put the heat box, fan and conduit in without the heater core. Come to think of it , it would be ideal to replace the heater core with an AC evaporator if I was ever to retrofit one in the car.
      Glad you made it safe to Oregon and got a roof over your head despite having to pay for grocery bags . Here in Maine we are in the same pickle. We knew it was coming, and it was supposed to be implemented right as the chinky-pox CF hit, so they delayed it a couple years. In the meantime we hoarded tons of them to keep us going for a few years. Love the photos of you and Phil.