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1949 Chevy Heating and Air Conditioning - Crimps 'n' HoseFrom the January, 2010 issue of Rod & Custom By Kev Elliot
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You may remember that last month I installed a Vintage Air evaporator under the dash (almost!) in my project '49 Chevy, converted the stock heater controls to operate the air conditioning, and fabricated a bulkhead fitting to route the plumbing from the interior to the engine bay. Well, it's been a busy month, as not only did I plumb the brakes (see page 40), but also plumbed the air and heater hoses, and wired the air conditioning. I'll not go into great detail on the wiring, as not only is it simple with wiring harnesses supplied by Vintage Air, but it's covered in the instruction manual that comes with the system; and other systems will be different. I will show you the major components, like the trinary safety switch, heater control valve, and their associated relays. Likewise, I won't delve into how auto air conditioning works, since we covered that in great detail in our May '08 issue. What I will concentrate on is the plumbing and how to crimp the hoses, as well as how to prepare them for crimping if you're not going to do it yourself. And let's face it, most of you won't because the tool is somewhat expensive and impractical if you're only going to tackle one or two systems. Your local automotive A/C supply house should be able to crimp hoses, but you need to make sure they crimp the fittings exactly where you want 'em, using the proper crimping tool! After installing the Edelbrock... After installing the Edelbrock cast-finish water pump, I fitted the polished Vintage Air Pro Line compressor/alternator bracket. Not only does this align the two components, but allows them to clear the tall valve covers required to clear the roller rockers in the Smeding 383. Make sure you install all of the bracket's hardware before tightening any of the bolts. Vintage Air offers its Sure Fit A/C kits for a wide range of cars with tailor-made bracketry, moldings, and ready-crimped hoses or hard lines, but can also help you with universal components. If you're like me, you require a unique system. Having never installed an A/C system before, I was pleased to see the Vintage Air kit was very complete, the instructions were easy to understand, and the whole deal was simple to accomplish if a methodical approach was taken. Yes, I actually read the instructions! Once the major components-the compressor, condenser, dryer, and evaporator-were mounted in the car, I plumbed the whole system without crimping any fittings, as the hose pushes into the fittings and will stay there during mockup. This turned out to be a wise move, as I moved the location of the hoses on the bulkhead fitting more than once, and added a Pro Line TiteFit hard line kit to the compressor after running hoses to it at first, for a neater appearance, and ease of removing the valve covers down the road. Once I was happy with the way the hoses ran, and had ensured that all the writing on them was "facedown" so it couldn't be seen, I marked the hoses and fittings and was ready to get crimping. Or at least I was ready to let our resident tech center whizz, Jason, get crimping. Oh, and while it should be obvious, there's a circuit to be followed with the hoses; from the evaporator to the compressor, then to the condenser, to the dryer, through the safety switch, and back to the evaporator. Make sure you get this right and use the correct ports on each component! Some of the hoses and fittings are different sizes. There are three used-No. 6, No. 8, and No. 10-but it's still worth mentioning. Route the refrigerant lines as per the Vintage Air instructions and you can't go wrong. Before the above bracketry... Before the above bracketry was fitted I installed these bungs in the water outlets of the intake manifold, as the larger one would be impossible to get to afterward. There are a couple of other things worth mentioning before we dive under the dash, and that's that the evaporator needs a drain, for which I haven't decided where to drill through the floor yet. One refrigerant and both the heater fittings are tucked way up behind the evaporator and aren't easily accessible in my particular installation. If your's is the same, do yourself a favor and make sure you can access any hose clamps from underneath. This is especially applicable if you do as I did and attach these hoses before you fit the evaporator. Plan ahead, it'll be worth it in the future. It should be noted that the four major components are sealed and filled with dry nitrogen under pressure, and the caps should not be removed prior to installation, as this will cause them to collect moisture and lead to reduced performance or even failure. Once the caps have been removed, you should aim to plumb the system as quickly as possible and have it evacuated to boil away any moisture before charging with 1.8 pounds of R134A refrigerant. Before the system can be used, since I modified my controls using a '61-62 Impala conversion kit, I'll have to calibrate the control panel, but again the instructions for this are in the conversion kit manual and are straightforward. Finally, there's not much point having A/C in an un-insulated car, so invest in some form of heat insulation, and make sure all door and window seals are doing their job. OK, sleeves rolled up, here we go.  The compressor and Powermaster...  The compressor and Powermaster alternator were bolted up next, with the Heim-joint bars providing adjustment. With the tall valve covers there isn't a lot of adjustability, so selecting the correct length belts will be crucial.  More goodies from the Vintage...  More goodies from the Vintage Air boxes included the dryer, various sizes of A/C hose, all the relevant fittings, trinary safety switch, heater control valve, and necessary wiring.  You'll save a lot of time...  You'll save a lot of time and grief by investing in a pair of hose cutters like these, guaranteeing a straight cut every time.  Once I'd practice-plumbed...  Once I'd practice-plumbed the entire system (you can push the A/C hose into the fittings without crimping them to test-fit) it was time to crimp the hoses. You'll highly unlikely possess the correct, and very expensive, tool to do this, so mark all the joints with a Sharpie (arrows) in a place where they won't be seen to preserve the alignment, and take them to your local specialist store. Straight fittings won't need marking but any angled fittings will. I ensured that the writing on the hoses was at the bottom, and therefore unseen in the final installation when I did this.  Each fitting has a small hole...  Each fitting has a small hole (arrowed) which enables you to ensure the hose is pushed all the way into the fitting. A few drops of refrigerant oil on the inside of the hose helps it slide right in.  Our Tech Center possesses...  Our Tech Center possesses an ATCO Crimp Die kit, so I could crimp the hoses in-house. Designed specifically for ATCO beadlock fittings, it features six sets of quick-change dies and produces the OEM-style triple bubble crimp that is recommended for R134A refrigerant. Several different types of these crimpers are available from Vintage Air.  Once the correct die for the...  Once the correct die for the size hose was selected, it was installed in the tool, which was mounted in a vise.  The hose and fitting were...  The hose and fitting were then placed in the die, ensuring they were still in alignment, and the bar at the top of the tool locked in place.  The small arm that's been...  The small arm that's been swung round against the fitting since the last picture is a height guide, with the fitting pushed up against it, ensuring the crimping is done in the correct location. An air wrench was used to tighten the tool, and hence crimp the fitting.  I used stock GM pulleys on...  I used stock GM pulleys on my motor, but the water pump pulley ever so slightly fouled on the body of the Edelbrock water pump. Speedway Motors sell these pulley shims to provide correct alignment. I only had to use one 1/16-inch shim, though the kit contains two 1/16- and one 1/8-inch shims. On the left is a crankshaft pulley spacer to match the upper pulley's alignment.  Here's what the finished crimped...  Here's what the finished crimped fitting should look like, OEM style and leak free.  The drier has to be located...  The drier has to be located between the condenser and the evaporator. I mounted it at the front of the inner fender, which obviously needs a little repair work before it's ready for paint!  The condenser (listed in the...  The condenser (listed in the Vintage Air catalog as for a '39-40 Ford or '55-57 Chevy) was mounted in front of the radiator, a triple flow design from U.S. Radiator, using Vintage Air's universal brackets. Be sure to mount the condenser with the larger No. 8 fitting at the top. The refrigerant lines were routed through the radiator support panel and will eventually pass through suitably sized grommets.  I used stock GM pulleys on...  I used stock GM pulleys on my motor, but the water pump pulley ever so slightly fouled on the body of the Edelbrock water pump. Speedway Motors sell these pulley shims to provide correct alignment. I only had to use one 1/16-inch shim, though the kit contains two 1/16- and one 1/8-inch shims. On the left is a crankshaft pulley spacer to match the upper pulley's alignment.  Alignment of all the pulleys...  Alignment of all the pulleys is vital, and now's the time to check it. I used an over-long belt to check that all the pulleys were true in relation to each other.  In order to tension the belt...  In order to tension the belt while checking the pulley alignment, I used Vice Grips to clamp the excess under the crankshaft pulley.  With all the refrigerant lines...  With all the refrigerant lines plumbed in the engine bay, I moved to the interior. With the evaporator removed, this is how the fittings pass through the firewall using the tube I fabricated last month. I routed the heater hoses at the top, and the A/C lines at the bottom, as they're not as flexible as the heater hoses and there's limited room for maneuver once the evaporator is installed.  Both the heater hose (shown...  Both the heater hose (shown here) and refrigerant line fittings use rubber O-rings to seal the joint. Applying a little refrigerant oil (supplied) ensures they don't snag, tear, or otherwise get damaged during installation. Add a couple of drops of refrigerant oil to the threads on the fittings as well.  I installed the heater fittings...  I installed the heater fittings and this beadlock refrigerant fitting before bolting the evaporator in place, as they're almost impossible to get to afterward in my application. Actually I installed over-length heater hoses, ensuring the hose clamps faced downward should I need to access later, and crimped the beadlock fitting to an over-long refrigerant hose, meaning I could fine-tune their lengths once the evaporator was in place.  I had to make all the interior...  I had to make all the interior hoses 4 inches longer than necessary in order to be able to pull the bulkhead fitting out slightly, enabling me to tighten the fittings. Hose clamps still have to be added to the heater hoses here. While my idea was to use the original fresh-air tubes to hide much of the A/C and heater plumbing, I'll admit I made life unnecessarily complicated for myself with this arrangement.  This picture belies just how...  This picture belies just how tight for space everything is in this corner of the firewall. I even had to move the evaporator up by an inch, which puts it close to the wiper mechanism, in order for the heater hose you can see running across the top of the others (arrow) to clear. If only I'd welded up that huge hole in the firewall and used a regular bulkhead fitting as it was meant to be used, it would have been simpler.  With the plumbing complete,...  With the plumbing complete, I ran the duct hose from the various ports on the evaporator to the original Chevy de-mister vents, and to where I'll mount the louvers. Be sure to slightly stretch the duct hose and make the turns as smooth as possible to maximize airflow. But more on that particular part of the project another time!  Next came the easy part; hooking...  Next came the easy part; hooking up the wiring harness. Vintage Air makes this simple in the extreme and the power and ground harness is simply plugged into the evaporator next to the control panel wiring. Be sure to run the main harness ground to the negative terminal of the battery. Good grounds are essential with any electronic system.  More simplicity. This harness...  More simplicity. This harness also plugs into a female plug on the evaporator. The white wire is ground while the red leads to a 30-amp circuit breaker.  Here's the circuit breaker...  Here's the circuit breaker (top), while the two relays are for the heater control valve and the A/C compressor. These are supplied pre-wired and the wiring diagram in the comprehensive instruction booklet is simple to follow. I mounted these just in front of the A-pillar, where they'll be covered by the kick panel.  This is the trinary safety...  This is the trinary safety switch, which not only cuts off the compressor clutch at 30 psi or 406 psi, but also sends an electric fan engagement signal at 254 psi. Connect the trinary switch fan trigger to the same relay as your engine temperature switch. This arrangement will engage the fan with either engine temperature or A/C pressure. If you're running a mechanical fan, you only need a binary safety switch to cut off the compressor clutch at the high or low pressures. The trinary switch is mounted on the outside of the bulkhead fitting in the line between the dryer and the evaporator. It can be installed anywhere in the high-pressure liquid line between the condenser and the evaporator.  Mounted in the heater line...  Mounted in the heater line from the intake manifold to the evaporator, the heater control valve flows left to right (as shown here). The valve is directional, so pay attention to the arrow on the decal. Remember that the hose from the intake manifold is the high-pressure side, while the water pump is the low-pressure (suction) side. The heater control valve installs in the high-pressure line!
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