1972 Chevrolet Corvette Scarlett Project Car - Cooling System and Hydroboost

Going With The Flow

Jeremy D. Clough Aug 19, 2014 0 Comment(s)
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Factory Core Support Removed 2/22

6. The front of the engine compartment with the factory core support removed. The core support is held in place through the three diagonal holes, as well as two bolts at the bottom. Access to the diagonal holes may be difficult: we had to trim a little fiberglass inside the fenderwell to get to the top passenger-side bolt.

Radiator Hoses 3/22

7. Since this isn’t a factory installation, we couldn’t just buy radiator hoses by make-and-model. Instead, we used pieces of wire bent to match the general shape of hose we needed and then compared that to hoses in stock at the local O’Reilly. Word to the wise; write down your part numbers.

Steam Line Install Motor 4/22

8. Somehow our motor made it here without a steam line, so we had to install one, which required removing the throttle body as well as the bracket for the fuel pressure regulator that mounts to the throttle body screws. The steam line, which is partially covered with the black hose, connects the two steam vents on the front corners of the motor, and has a nipple for a hose that connects to the radiator.

Upper Hose Configuration 5/22

9. The final upper hose configuration, with the upper radiator hose and the steam line. The left side of the steam line goes to the block where it attaches to a nipple on the crossover, and the right side loops under the upper radiator hose and seats on the radiator beneath the radiator hose. After ensuring the aluminum on top of the radiator was thick enough, we clamped the steam line to it using self-tapping screws.

Cam Cad Cnc Mill 6/22

10. We have machine tools, and aren’t afraid to use them. When we realized we’d have to make an overflow bottle, we cut open an old aluminum A/C drier to use as a starting point. While I turned a bung for the bottom of the bottle on the lathe, Tray drew the bottle’s lid in a CAD/CAM program so he could cut it in the CNC mill.

Overflow Bottle Components 7/22

11. The components for the overflow bottle, ready to be welded up: The A/C drier that we cut to make the bottle itself, the CNC-machined lid, and the bung for the bottom. The elbow will be mounted in the bottom, and the air vent threads into the top.

Mounted Overflow Bottle 8/22

12. Once the bottle was complete, we bent and welded on a mount, then bolted it in place on the fenderwell and clocked the lower 90-degree fitting in the proper direction to meet the overflow hose from the radiator filler neck. The bottle will come out for polishing before final installation.

Heater Hose Fittings 9/22

13. As we covered in an earlier installment, we had to relocate the heater hose fittings from their ordinary position on the water pump so they would clear the front suspension (the original holes are shown here plugged beneath the current hose location). With this done, to seat the hoses to the block we just slipped them on the nipple and tightened the hose clamps.

Vintage Air Ac 10/22

14. We’ll cover the full installation of the Vintage Air A/C in a later installment, but for the time being we’ll note that the firewall end of the heater hoses had to be seated on their respective fittings on the new heater core.

Lower Heater Hose 11/22

15. The lower heater hose needed to have a valve installed, so we measured the length of the valve, cut a section that long out of the hose, and seated and clamped the hose. The valve had a molded arrow indicating flow direction, and a contrary label on it that read “disregard molded arrow,” which I did.

Inline Valve Hose 12/22

16. With the lower heater hose cut for the inline valve, we oriented it downwards to provide the cleanest appearance possible: This photo is taken from outside the passenger-side fender vent.

Hydroboost System 13/22

17. Here’s the Hydroboost system provided by Hydratech. A replacement for the factory power brake booster, which is operated by engine vacuum, the Hydroboost operates the power brakes using pressure from the power steering pump.

Hydroboost Braided Steel Hose 14/22

18. The Hydroboost comes with both braided steel and rubber hose and loose fittings, a mix of -AN and NPT, and you’ll need to cut and assemble them for your specific application. These are the lines from the bottom of the Hydroboost that go forward to the power steering pump and valve.

Rubber Return Hose 15/22

19. At the pump, the rubber return hose goes back into the power steering reservoir, while one braided steel line goes from the bottom of the pump to the Hydroboost, and another from the Hydroboost to the valve. The braided lines are held in place with the billet hose clamps, always a nice touch.

An Adaptor 16/22

20. Improvise, adapt, and overcome. For our application, we needed to weld up a fitting combining the factory part and a provided AN adaptor so we could connect up the hoses properly.

Cooling System Hoses 17/22

21. The finished cooling system, complete with hoses and recirculating overflow bottle. The radiator itself is hidden behind the Vintage Air condenser. Since the condenser brackets are held in place by the same bolts that hold the upper radiator brackets, it had to go in at the same time.


Vintage Air
San Antonio, TX 78266
Corvette Central
Sawyer, MI 49125
Hydratech Braking Systems
Lebanon, TN 37090
Brighton, MI
Street Shop, Inc.
Athens, AL 35611


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