For uniformity, the Vintage Air system’s A/C and heater hoses were made from Pure Stealth reduced barrier hose with the triple white braid pattern. The clamps securing the hoses to the inner fender are also from Pure Choice.
It may be hard to believe but, back in the day, the coolest way to improve the plumbing under a hot rod’s hood was to add some red plastic fuel lines and polish brass fittings. The problem was that the fuel lines became brittle, cracked, and leaked, creating the risk of disaster, and the brass fittings would turn dull overnight. Today, we have a variety of plumbing options from Pure Choice Motorsports that not only look great but are also safe and durable.
Rex Watson of Pure Choice Motorsports assesses the plumbing options on Brian Brennan’s Corvette. The choice was made to go with Watson’s line of Pure Stealth braided hoses and black fittings.
Rex and Annette Watson are the owners of Affordable Street Rods, located in the small town of Peabody, Kansas. When given the opportunity, they decided to expand their business by acquiring Pure Choice Motorsports. A leading supplier of automotive plumbing products, Pure Choice offers high-performance fittings, hoses, tubing, and accessories. The Watsons also carry the Pure Stealth line of plumbing products with the company’s proprietary black ceramic coating. In addition to fittings, the Pure Stealth line includes black braided hoses with 24 color options for accent braiding in a nearly infinite variety of patterns. The braid covering on these hoses isn’t a sleeve; it’s adhered directly to the hose so it will never slip or come apart.
To give us some pointers on plumbing, Rex stopped by Hot Rods By Dean to see what was needed to hook up the power steering, air conditioner, and heater in Brian Brennan’s C3 Corvette. While there are a variety of options for making all those connections, including E-Z Clip hoses and fittings, the decision was made to use a Pure Stealth reduced-barrier braided hose with Pure Stealth crimp fittings so everything would match.
Pure Stealth premade power steering hoses are available in custom lengths with straight, 45-, or 90-degree swivel fittings. In this case, both the high-pressure and return hose use AN fittings.
Pure Choice and Pure Stealth offer various power steering hose kits ranging from 8 to 30 inches in length, in 2-inch steps. The pressure hose arrives preassembled with swivel hose ends for easy adjustment. The low-pressure hose will have a single fitting attached and is cut to length, as the connection at the reservoir is made with a Pure Stealth finisher clamp. Typically, these power steering hoses use two types of hose: PTFE for the pressure line and neoprene for the return. This is because when the return line is fastened to the power steering pump with a hose clamp, the PTFE is too stiff for the clamp to squeeze sufficiently to prevent leaks. In Brennan’s Corvette, both hoses are PTFE and use crimp fittings (available by special order).
A properly crimped fitting should be evenly compressed all the way around. This example also includes a service port for evacuating, charging, and checking system pressure.
For A/C lines, the decision was made to use Pure Stealth reduced barrier braided hose, again with crimp fittings. Rex explains that making custom hoses is straightforward. After carefully measuring the Pure Stealth braided hose or standard reduced barrier hose, it is cut to length—it’s important to make a square cut. The fitting is then slipped onto the hose until it bottoms out and is oriented in the correct direction. To prevent damaging the finish on the fitting, the supplied “crimp cloth” is wrapped all the way around it and secured with a short length of masking tape. A dedicated crimping tool is required to secure the fitting. The type offered by Pure Choice is handheld, which means it can be used with the hose in the car, unlike the type that must be clamped in a vise. After completing the A/C hoses, Rex used the same procedure to make up the heater hoses.
The finished braided Pure Stealth hoses and crimp fittings are not only functional and look clean, but matching them all shows great attention to detail—plus, they’re much cooler than red plastic fuel lines. MR
There are more than a dozen sizes of power steering adapter fittings available for AN lines—Pure Choice has them all. In this case, a 9/16-18 to -6 was used on the high-pressure side of the rack with a 5/8-18 to -6 on the return side.
AN Fittings
When discussing fittings, the designation AN is often used—a term that may not be familiar to everyone. The AN refers to Army/Navy, a system developed by the government during World War II to ensure the interchangeability and compatibility of parts made by different manufacturers. AN fittings are used with 37-degree single flares that have reinforcement sleeves (these 37-degree flares are also found on JIC hydraulic fittings), as opposed to 45-degree automotive fittings and inverted flares.
The AN system uses numbers to identify different sizes of metal tubing and their corresponding fittings, with the same numbers also assigned to the hoses and their ends. Known as dash numbers, these indicate measurements in 1/16-inch increments. For example, a -3 line equal 3/16 inch, a -8 is ½ inch, and so forth.
This is a beadlock fitting for standard barrier hose; it must be secured by crimping. The small hole at the end of the fitting is used to verify that the hose is fully inserted into the fitting when the fitting is assembled.
Crimping beadlock hose ends requires the proper tool and dies. Pure Choice sells this handheld example (they are also available to rent).
A properly crimped fitting should be evenly compressed all the way around. This example also includes a service port for evacuating, charging, and checking system pressure.
Vintage Air and Pure Choice offer black, reduced barrier, and E-Z clip hoses. Both will make tighter-radius bends than standard hose, making installation easier.
The fittings used with the E-Z Clip barrier hose fit inside the hose. Note the O-ring on the fitting (there are two) that helps seal the connection. A drop of PAG oil should be applied to the O-rings during assembly.
Instead of crimping, E-Z Clip fittings are secured by an end cage that snaps into the groove in the fitting.
The E-Z Clip end cage is locked onto the hose with clamps that are secured with a special tool (also available from Pure Choice). Once locked in place, they cannot come loose.
Here is a completed E-Z Clip installation done by Dean Livermore. They look clean and are easy to install at home.
The engine in Brennan’s Vette was equipped with a common power steering pump and plastic fluid reservoir with an integral return line fitting. That fitting would have to go.
Careful cutting on Livermore’s band saw made quick work of removing the fluid reservoir’s return barb.
With the return barb removed, the remaining hole in the reservoir was threaded with a ¼ inch NPT (National Pipe Thread) tap.
To connect the return line, a Pure Stealth -6AN x ¼ inch NPT x 90-degree (PN X822-06D) was installed in the reservoir.
To snake through the tight confines of the Detroit Speed & Engineering front suspension, both power steering hoses were equipped with 90-degree swivel fittings.
Typically, the heater hose connection on the Vintage Air Front Runner is made with the fitting on the right side that accepts a heater hose and a clamp. In this case, Watson used a ½-inch NPT-to-#10 O-ring adapter to fit a #10 45-degree heater hose fitting.
The Pure Stealth beadlock fitting on the water pump accepts a reduced barrier #10 A/C hose (used as a heater hose) that matches the A/C and power steering hoses.
This is a problem solver—Watson installed a Pure Stealth #10 Tite 90-degree Elbow With Swivel Nut (PN X15170) in the intake manifold for the heater hose connection.
To tuck the hose in tight, a 90-degree reduced barrier beadlock fitting was used to wrap around the front of the valve, right side valve cover.
Both reduced-diameter heater hoses are #10 with the same triple white braid (PN XX31400) and crimp fittings found on the A/C hoses.
To protect the fittings, Pure Choice supplies “crimp cloth” to wrap around Pure Stealth fittings during the crimping process.
Although the proprietary coating on the fittings is durable, crimping can make the finish appear “polished” where the dies press against it. The crimp cloth prevents that.
This is a Pure Stealth #10 reduced barrier and E-Z Clip heater hose adapter fitting (PN X361403), used to connect from the 5/8-inch heater hose to the Vintage Air heater control valve.
A short section of standard 5/8-inch heater hose was used to connect the #10 hose to the heater valve.
The Pure Stealth Black SD7B10 fitting kit (PN X045003) attached to the compressor accepts a pair of 45-degree beadlock fittings with service ports. The #8 discharge fitting (PN X355220), the #10 suction line fitting (PN X355230).
Vintage Air’s SureFit Corvette kit included preformed lines to connect the condenser to the system. For Brian’s Corvette, the hard lines were shipped to Pure Choice for coverage with their Pure Stealth ceramic coating.
The Vintage Air condenser lines certainly simplify the installation process as they fit through factory holes in the core support.
On the engine side of the core support, 45-degree beadlock fittings were attached to the condenser lines. The #6 line will connect to the evaporator, and the #8 line comes from the compressor.
Pure Stealth brings underhood detailing to a whole new level—these are reduced barrier service port caps (PN X15090-5). An O-ring inside the cap seals the service port and protects the Schrader valve from debris.
To protect the finish on AN fittings, Divers Street Rods offers these AN wrench inserts from NotcHead. The kit includes six inserts, -3 through -10, plus a ¾ inch for the other side of a -6 line.
Made from super-tough Delrin, these wrench inserts fit into standard SAE wrenches, eliminating the need for a special set of AN wrenches.
To make clean, accurate cuts in barrier hose, Pure Choice offers this tubing cutter (PN 48-22-4204) to buy or rent.
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