Lark Heater rebuild, Part 3: Installation

In Part 1, we yanked the old heater from the car. In Part 2, we made it all pretty again. In Part 3, we'll tackle putting all the disparate parts back together and making a functioning system again.

As the diagram shows, there are quite a few parts that have to go together - more little bitty ones than you'd generally expect. Luckily, as mentioned in an earlier post, most everything essential is available new from Studebaker vendors, even previously hard-to-find things like the Ranco water control valves that invariably wear out and leak.
 
First things first: Assemble all your bits. Here you can see all the stuff I've collected that make up the Lark's heating system: blower and core housing assembly, core gasket, newly-rebuilt heater core, refurbished heater/diverter box, molded coolant supply and return hoses, firewall hose grommets and Ranco valve + mounting bracket.

Before beginning installation, take a moment to lubricate your heater control cables. There are three; one that goes to the water control valve, one to the defroster mode flapper in the heater box, and a third to the air control flapper, also in the heater box. Studebaker used coil-wrapped control cables, so they are easily lubricated. I drenched mine liberally using a spray silicone lube.

The first item to go back in is the core/blower assembly, but first we have to reunite the core with its case.

I had my core rebuilt by what I think is the last old-school full-service radiator shop in North San Diego County, S&S Radiator King in Oceanside. S&S has been at it over 30 years, and they can fix or fab just about anything. I took my old core to them for testing and they confirmed that it was dead. "We'd solder one hole, and another would open up," said Mike, the owner. They searched around for a new core, but that size isn't made anymore. They scared up one that was about a quarter inch narrower, but still fit the tanks, and my heater was back among the living.

When I disassembled the core initially, I found that the factory used a generous glob of plumber's putty in each corner to keep the core from vibrating around in its case, so I did the same. I also found a small, triangular rubber bit that was placed in a crevice in one of the tanks; I don't know why it was there, but I saved it and replaced it.

Once the core was seated back in its case and the two mounting screws secured it to the flange, it was ready to re-mount under the dash.

The core is a very tight fit in the dash opening, and the mounting studs affixed to the dash are at the extreme corners of their mounting positions, so the core case must go onto the studs absolutely straight in order to make it up into the hole correctly. Don't forget to place the foam sealing gasket around the core before beginning the reassembly. I didn't use any sealer or caulk to hold the gasket on; bolting it into place is all the sealing it needs.

The core is held on by four nuts with anti-shake shoulders, like the ones shown at the right. You've probably already seen that the black ground lead from the blower motor ends in a ring terminal; it needs to be placed between the core case and one of these washers to complete the blower motor power circuit. Tuck the other two leads out of the way for a moment.

Now that the core and blower are reinstalled, we can mount the Ranco water control valve back under the dash. On earlier cars, this valve was mounted in the engine room on the firewall, but ours is in much closer proximity to the core and easier to service and install. Note the capillary tube that senses the ambient temperature; this needs to be coiled and located on top of the valve. I wound mine carefully around the handle of a screwdriver. The bracket screws to the lip on the underside of the dash with two big, honkin' sheet metal screws. It's best to connect the control cable to the valve before mounting it, since the tab that the cable screws to is harder to access with the valve in place.

Here you can see the relationship of the inlet and outlet nipples on the core and water valve, now that both have been mounted in the car:

What you can't see in the photo above are the holes in the firewall through which the heater hoses enter the cabin. That's right -- they're behind the blower case. There's enough room to get them by the case and onto their respective nipples, but only just.

It's time to start connecting hoses. The factory shop manual recommends using gasket shellac to paint the nipples with; not only will this lube the metal and make it easier to get the hoses on, but it will set up quickly and seal any gaps between hose and pipe, preventing leaks. I got a bottle of ol' skool Indian Head gasket shellac from my friendly local NAPA, where they've gotten to know me on sight since Barney arrived :) It works as advertised: paint the pipe, slip on the hose and tighten the clamp - you're done.

The factory used spring wire hose clamps, by the way, but I hate those things, so I use tower clamps instead, available at any auto parts store.

Although the long hoses with the molded ends that run from the engine into the cabin are available from Studebaker International, the short molded elbow that connects the water valve outlet to the heater core inlet is not. I took the old elbow to my NAPA and, bless their hearts, they picked a molded hose out of their parts bin that filled the bill. (It's a lot closer in dimension to the original than the photo makes it look.) It's NAPA part #11658, in case you're in need of one.

As the Body Manual diagram shows, the straight outlet on the water valve connects to the short pipe on the heater core, using the molded elbow shown above. Once that's connected, it's time to connect the two long hoses from the engine.

The hoses need something to protect them from being cut apart by the firewall, so there are rubber grommets that perform that function, again available from all the usual sources.

I spent a while figuring out how to get the grommets and hoses mounted in the car, and on my first attempt, I tried putting them in their firewall holes and feeding the hoses through them. Wrong move; I should have known that the friction between the rubber parts would prevent this from working. And once installed, the grommets contract a bit too - there was no way this method would work.

I realized that I'd have to slide the grommets on the hoses, feed the hoses through the firewall (one at a time) and then finesse the grommets into place. As you can see, one lip of the grommet is split so that it can compress enough to fit through the sheet metal and grip the other side. Once you've got it started in the hole, you can use a wide screwdriver blade around the perimeter to ease it into position. Or, perhaps, a piece of twine in the mounting groove to install it like you would a car window. (I used the screwdriver.)

Be sure to secure the two hoses to the fender using the strap just behind the alternator. If yours is missing, you can fabricate one or get one used from Stude vendors. On V8 cars like mine, the shorter of the two hoses runs from the elbow on the top of the water manifold to the water valve inlet; the lower hose runs from the lower nipple on the manifold to the long pipe on the heater core.

If you have a 6-cylinder car, the top hose runs to the elbow at the rear of the head and the bottom hose goes to the nipple near the water pump.

When the connections are complete, the core and valve look like this:

The next step is to install the diverter box and connect its control cables. Installing the diverter box is pretty simple; just slip the end over the blower outlet and raise the other end, then secure it to the bracket on the dash using the big screw that held it in. Don't forget to include the wiring harness clip; tuck the wire bundle that goes to the neutral safety and directional switch into it and you're done.

Now for the control cables. Slip them onto the actuator arms for the fresh air control and defroster diverter, and secure them to the metal tabs using the little squiggly spring clips discussed previously. The tang goes into the little hole in the mounting tab, and the other end snaps over the end of the tab These clips are tough to get on by hand, especially if you bought new ones; the easiest way to do it is with a pair of pliers to snap the end, as you can see in the photo below:

After the cables are on, you can connect the defroster ducts to the outlets on the diverter box. As I did with the other end, I used Zip ties to make sure the hoses don't blow off or come loose. I also used a Zip tie to secure the longest hose to the edge of the dash using one of the convenient factory holes. The factory used a metal strap of some kind to do this, but it's no longer available and the Zip tie is just as good.

There's just one thing wrong with this picture: after I connected the blower leads to the dash harness, there was a lot of extra wire. There was no way I was going to leave it like that. More modern tech to the rescue: these spiffy little self-adhesive cable locks I found in the automotive department at Wal-Mart. A couple of these stuck to the bottom of the diverter box and the mess was tidied.

Only one thing left to do: install the screen filter that keeps leaves and other debris from getting into and plugging the heater core. This is a woven metal mesh that slips into the firewall from the engine compartment, and has a rubber seal on the edge that keeps fumes and moisture out. These are available from Studebaker International. My original was shredded thanks to the rodent tenant, so I got a new one.

Congratulations! The heater is now functional again, ready to make your Stude comfy on those winter outings. It's one of the few times when plenty of hot air is a good thing :)