A/C for a Dinosaur

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Dino is one unique old 4×4, with a one-of-a-kind history mainly revolving around service to learning about the world we live in through research and education. This service has been in support of such internationally renowned institutions as the American Museum of Natural History, the Smithsonian, and countless universities. Add to that its classic looks and rugged nature, and you can see why we are smitten. What we’re trying to say is Dino is rad, fresh, dope, cool.

But the inside of Dino isn’t always so fresh and cool. The main issue is we live in the desert Southwest. The dry climate will help Dino live on much longer than he might last in a wet, damp environment, but the tradeoff is blazing sun that’s hard on the paint, interior, and tires. The interior is a stifling greenhouse in the summer.

We’ve made numerous upgrades to this old Suburban: power steering (over the factory manual steering), power brakes (over the manual four-wheel drums), fuel injection (from a leaky two-barrel carburetor), limited slip differentials, and more. But now that we are staring down the barrel of another Arizona summer, we thought it amply prudent to contact the folks at Old Air Products to bring Dino into the age of acclimatized air. A/C, that is. Our plan is to install a system that will keep the air inside Dino at a tolerable heat level, come what may.

A C For 1970 Suburban Dinosaur 2 Photo Old Air Products sent us one of its Hurricane Complete A/C Heat and Defrost Systems with underdash vents and an electronic control unit. This is a complete front system with everything you need to install A/C and heat minus the R134. Since we live in the desert, we also have plans to augment the system to make it a little bit more efficient at cooling down such a big old beast as our Suburban. If you haven’t messed with A/C systems, or aftermarket A/C, we’d suggest checking out some install and repair videos online before starting this project. We started by disconnecting and removing the battery, factory heater, and vent system. It’s easiest to remove the glovebox and glovebox door. We had to drop the back of the inner fenderwell also and temporarily remove the passenger-side hood hinge. We also removed the push/pull cables and dash-mounted control unit.

Luckily, Old Air Products is a company that carries all sorts of automotive HVAC components and has applications for 1967-1972 Chevy trucks (and more). And we’re tapping another trick from the minds of 1970s GM factory engineers and trying to add a rear air unit to aid cooling the cavernous Suburban interior.

Will it work? We’ll have to see once the outside temps routinely hit the triple-digits again, but with parts in hand and a 120-degree-plus summer looming, we are gonna find out soon.

A C For 1970 Suburban Dinosaur 3 Photo We always suspected that there were unwelcome squatters inhabiting Dino while he was in storage between field seasons. Several generations of mice may have been born in Dino’s heater and vent system. In fact, GM designed the system much like a rodent habitat from the pet store. The heater fan is even a “squirrel cage” design, with easily accessible air ducts like that blue plastic hamster tube. The Old Air Products Hurricane unit won’t afford the mice any space for a swinging pad. Since they pee and poop where they sleep, we’re pretty sure we won’t miss them.

A C For 1970 Suburban Dinosaur 4 Photo With Dino’s huge old heater box out of the way, we could test-fit the Hurricane unit. It is held in place with a mounting bracket and a studded block-off plate/mount that sandwich the firewall. You have to test-fit the unit to mark and then drill a hole for a condensation drain on the front. One nice thing about this whole system is you don’t have to cut any huge holes in your rig to install it (you do have to drill a few holes), so theoretically you could go back to stock if you wanted too. Also, that means you don’t have to make cuts, clean up the cuts, avoid jagged edges, and so on.

A C For 1970 Suburban Dinosaur 5 Photo Looking in from the engine bay you can see the outer black powdercoated block-off plate/mount. The Hurricane has two heater ports and two connections for the closed-loop refrigerant system. This ginormous four-holed grommet fits over the ports and in the hole precut in the block-off plate/mount. We used a spray bottle with some soapy water to help work the grommet in place over the fittings and heater pipes.

A C For 1970 Suburban Dinosaur 6 Photo We then installed the brass 90-degree expansion valve, being sure to lubricate a No. 8 green A/C O-ring with the included refrigerant oil. We then mounted the pigtail of the sensor to the upper A/C tube coming from the unit. This pigtail is then held in place with the supplied metal clip and wrapped with a few inches of the included black insulating tape.

A C For 1970 Suburban Dinosaur 7 Photo From here we installed some of the ducts for the defrost system coming off the Hurricane unit, and then installed the wiring harness and electronic in-dash control unit. You can then plug in most of the wiring harness to the Hurricane unit’s blower motor and thermostat, control actuators, and A/C switch. We also routed the heater control wiring, and compressor safety switch through a factory hole in Dino’s firewall using a supplied grommet. There are also a couple of ground wires that need to be attached, control unit illumination wires, and two 12-volt keyed wires that need power.

A C For 1970 Suburban Dinosaur 8 Photo Next we installed the supplied compressor bracketry to the front of the engine. Old Air Products has several different compressor mount configurations depending on what engine and what accessories your engine has. We could have painted or otherwise coated the brackets, but since Dino oozes patina (as well as dino juice) we’ll let it pickle in the open air under the hood to match the rest of the rig. The mount we used grabs two water pump bolt-holes and two intake manifold bolt-holes. The kit comes with necessary spacers and longer hardware for mounting the brackets.

A C For 1970 Suburban Dinosaur 9 Photo The Old Air Products instructions say you can mount the compressor upright (as shown) or on its side (with the ports either facing driver or passenger side if necessary for hood clearance), but you cannot mount the unit upside-down. The unit holds oil that needs to stay put to lubricate the system. Since we don’t have an issue with hood clearance and we want to ensure the compressor lives a long and happy life, we mounted it in the preferred position with the ports facing up.

A C For 1970 Suburban Dinosaur 10 Photo With the compressor installed we moved onto mounting the condenser and drier. We assembled the condenser, drier, formed lines, and mounting brackets following the included instructions. We then removed Dino’s grille, center hood latch mechanism, and front bumper to make mounting all these parts possible. Again, this kit uses existing mounting points and holes so you don’t have to cut up your rig to install it. Kit-supplied grommets help protect the lines that pass through the core support.

A C For 1970 Suburban Dinosaur 11 Photo With most of the major components in place we started mounting the rubber hoses. These are premade with crimped ends and all the right fittings in all the right spots. The hoses are slightly longer than necessary to allow for engine movement and body flex. All the connections require either a No. 6, 8, or 10 green O-ring that you must lubricate before making the connection using the supplied tube of refrigerant oil.

A C For 1970 Suburban Dinosaur 12 Photo The kit comes with all the grommets you’ll need and all the hardware necessary to make solid mounts including screws, nuts, zip ties, and Adel clamps. This includes some rivets and a mounting plate that mounts to the battery tray, holding the two lines from the condenser and drier.

A C For 1970 Suburban Dinosaur 13 Photo Make sure to use two wrenches when tightening each of the A/C fittings to avoid damaging the components. Also, you don’t have to reef on these fittings to get them to seal—in fact, overtightening does more harm than good.

A C For 1970 Suburban Dinosaur 14 Photo With the hoses in place we moved on to wiring the compressor and pressure safety switch (sometimes called a binary switch). The green wire you fed through the firewall first goes to the safety switch, and from there more green wire goes on up to the wire coming off the compressor. Connectors and dust shields are included with the kit.

A C For 1970 Suburban Dinosaur 15 Photo We then routed the old heater hoses to the new electronic heater control unit. This keeps hot water out of the Hurricane when you run the A/C to make the system more efficient. We did have to supply about 18 inches of 5/8-inch heater hose to connect the electronic heater control unit ports to the Hurricane.

A C For 1970 Suburban Dinosaur 16 Photo We hinted earlier at making Dino’s A/C system more efficient and the folks at Old Air Products have had customers and installers add a second condenser to larger vehicles (much like modern Chevy Tahoes and Suburbans). In fact, in 1972, three-door Suburbans came with A/C as an option and even an optional rear air system. Our plans are to mount a second slim evaporator A/C unit (Old Air Products, PN IP-800) just below the roof behind Dino’s rear seat. To make this happen, we will have to add a T to the No. 6 hose running from the condenser/dryer to the primary evaporator, and another T to the No. 10 hose (suction hose) between the evaporator and compressor. Then we can run these two hoses all the way back into Dino, and build a rear A/C box (similar to the factory rear air Suburbans from 1972). Unfortunately we ran out of time to install and complete the rear air in Dino, but here is the IP-800, some of the fittings we will use, and the miles of hose necessary.

A C For 1970 Suburban Dinosaur 17 Photo Old Air Products also supplied us with a second receiver/drier to mount close to the rear evaporator. The job of a receiver/driers in the system acts to dry out the coolant, remove any particles in the system, and separates vapor from fluid refrigerant. It also serves as a reservoir for the liquid refrigerant. So a second receiver/drier will help supply the rear evaporator unit with fluid refrigerant.

A C For 1970 Suburban Dinosaur 18 Photo The rear unit also has its own 90-degree expansion valve that must be installed like the front expansion valve. Just like the other expansion valve, the pigtail is held in place on the other A/C tube using a metal clip. The pigtail is then wrapped with the black (and very sticky) insulating tape.

A C For 1970 Suburban Dinosaur 19 Photo This shows one of the two T fittings necessary to plumb in the rear evaporator unit roughly where we will install it. These fittings need to be crimped to the hoses by a special tool. We are waiting on a Mastercool Black Manual A/C Hose Crimper (PN 71550) to arrive. Old Air Products can supply you with one for your project too. Either way, the proper crimping tool must be used because crimpers for hydraulic hose can overcrimp the A/C hoses and damage the inner liner.

A C For 1970 Suburban Dinosaur 20 Photo This Old Air Products Hurricane kit is very comprehensive and even comes with a new glovebox liner. That’s an awesome detail that isn’t overlooked by the company. Good, because any old 4×4 that you might retrofit A/C into is probably gonna have a paper glovebox that will likely turn to dust when you try to remove it to install the condenser.

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