EVAP Testing Port Modification

The EVAP line connection style has changed on the 2020-2021 Corvette equipped with the 6.2L V8 engine (RPO LT2). If a vehicle requires the EVAP system to be tested for leaks, a modification must be made to the CH-52519 EVAP Service Port Access Tool.

If the CH-52519 EVAP tool is not modified, or a commercially available low profile fuel line disconnect tool is not sourced to be used, it will result in the CH-52519 EVAP tool not being able to be removed from the EVAP purge line. The rib located on the CH-52519 EVAP tool needs to be modified in order for the tool to be removed from the purge line.

TIP: Performing this modification voids the tool warranty for CH-52519.

To modify the CH-52519 EVAP tool, partially file down the rib (Fig. 17, #1) on the tool. File the rib evenly and do not file the rib flush as damage to the sealing surface may occur. Leave a small amount of rib material on the tool without damaging the sealing surface (Fig. 17, #2). This modification should not have any effect on how the tool works with other vehicles.


Fig. 17


Use care to not damage, cut, or scratch the tool when filing the rib. Any damage to the tool will result in the tool not sealing properly when installed.

Refer to Document I.D. 5757934 in the Service Information for more information about the installation location for the CH-52519 EVAP tool. (Fig. 18)


Fig. 18


– Thanks to Richard Renshaw


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One Comment

  1. Mike Allen says:

    Okay, so you want us to remove “some” material from the rib, but don’t give a specification. A simple outside diameter spec would do. Also the TIP says doing this modification will void the tools warranty. Why not just send a corrected tool or give more information on how to properly modify this one?

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