Corvette ZR1 Supercharger Cooling System Bleed DIY

Keep your C7 Corvette ZR1 intercooler temperatures low with inexpensive tools and some patience.

Like many modern high performance engines, the LT5 engine in the C7 Chevrolet Corvette ZR1 has a dedicated cooling system that focuses on the forced induction system. This “low temperature system” helps to keep air intake temperatures low and power levels high, but if air bubbles get into the system, it can cause the LT5 to run hot and no one wants that.

Fortunately, if you get air in the low temperature cooling loop, we have a thread here on Corvette Forum that walks you through bleeding the system. This thread was originally posted by “mityaz”, who provided a little background before sharing the video that he made (above).

Clearing Out the Supercharger Cooling System

As you can see in the video, the OP bought a vacuum pump and a few other odds and ends to make the bleeding system for his new Corvette ZR1. The process is time consuming, but it does a great job of carefully removing air bubbles from the system. In this case, he had a rock kick up and damage one of the radiators for the low temperature loop. In fixing that, it would have allowed a whole lot of air into the system which could not be removed without a system like the one in action in the video.

The first person to comment in the thread was “Bob U”, who pointed out that lifting the front end can help with the air removal process.

Great info. Thanks

Additional FYI, air will tend to go to the highest point in the system. If you jack up the front of the car or drive it up on jack stands, it will help by raising the filler ports above the supercharger cooling bricks which may still have air in them while sitting at normal ride height.

When the OP started this DIY thread, he hadn’t figured out how to run the second coolant pump, but over time, he was able to find the fuses needed to make both pumps run during the bleeding process.

ok, EXCITING UPDATE!!!

Fuse #76 is the second pump. Took a bit of searching thru wiring diagrams in the ACDelco manual. Works beautiful!!!

You have to connect the terminal that’s FARTHER from the windshield to +12v.

He included the picture here showing both fuses jumped.

Helpful Tips from a Corvette Z06 Owner

The next key information came from “LagunaSecaZ06”, who shared an array of pointers on the bleeding process.

Here’s some comments based on your video-

I found that the vinyl tube allows air to be introduced from the outside when under vacuum. Place hose clamp on the bottom to eliminate this possibility.

Raising the front of the car is very helpful.

Filling the system the first time is critical. Pulling the vacuum after filler does very little. See point 1 above.

You could always run the car to get both pumps running. On the Z06 they come on immediately after starting.

On the Z06 there is only one fill port. It may be helpful to pull a vacuum from one port and fill from the the other port. I never tried this, but it may be much easier and less chance of introducing bubbles.

Hope this helps.

He also included the video below of the bleeding process of the LT4 in his Corvette Z06.

After that, the OP and LagunaSecaZ06 continue the discussion, sharing key bits of information that can help bleeding the low temperature cooling system in the Corvette ZR1 or the Z06. If you are looking to bleed the cooling system in your C7 ZR1 or Z06, or if you have already done the job and you have information to add, click here to participate in the thread.

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