800670 - VB WRX Coolant overflow

800670 - VB WRX Coolant Overflow

2022-2023 VB WRX

Congratulations on your purchase of the COBB Tuning 2022-2023 VB WRX Coolant Overflow Tank! The following instructions will assist you through the installation process. Please read them BEFORE beginning the install to familiarize yourself with the steps and tools needed. If you feel you cannot properly perform this installation, we HIGHLY recommend you take the vehicle to a qualified and experienced automotive technician.



Parts List






Tools Needed



  • 3/8" ratchet

  • 3/8" 12" extension

  • 3/8" 6" extension

  • 3/8" 10mm socket


Hand Tools

  • Trim removal tool

  • 4mm Allen Wrench

  • 3mm Allen Wrench

Stock Washer Fill Replacement

  1. Park your car in a flat, level area and allow it to cool down. I recommend takng a moment to relax now. Maybe sit outside with a coffee, wave hi to the neighbors, maybe be extra nice to that one that knows you don’t like them just to confuse them.

  2. With your car cooled down, remove the trim clip holding the pipe for your washer fluid to the radiator support.

  3. With that clip removed, you’ll now want to remove the clip holding the hood release cable to the same support. If you pinch the bottom together it should lift out easily and then pop free from the cable.


  4. Pull upwards on the fill tube for your washer fluid tank and remove it from the tank, make sure the grommet sealing it to the tank doesn’t come out, reinstall the grommet if needed.



  5. Reach down and install the provided washer tank adapter into the grommet on the tank. Its recommended to make sure the grommet is a little wet before you push the fitting in to avoid forcing the gommet down into the tank.


  6. Install the washer fluid tube onto the fitting with the COBB logo up.

  7. Leave the cap out for now.


Overflow Tank Installation

  1. Find the grommet and lower bracket and install the grommet into the bottom hole.

  2. Next up, install the o-ring onto the coolant overflow cap.


  3. We’ll now install the support bracket. The two holes with the counter sunk ends will end up going towards the coolant overflow, so the other side where they’re a little closer together is the side we’re focusing on.

  4. The long groove cut through the bracket will be facing up. This is where your hood cable will now sit and it should hold in place loosely against the radiator core support. You’ll use the two stainless allen bolts with the two plastic COBB washers to loosely bolt this to the core support. Slip this over the washer fill tube and into place, then loosely bolt it on.

  5. We’ll now install the lower bracket to the frame rail. On manual transmission cars you’ll notice this unused hole on the frame rail just to the right of the stock overflow. For CVT vehicles there will be a 10mm bolt holding some hoses in place.

    1. Manual cars will simply use the provided hex head bolt to install the bracket to the frame rail.


    2. CVT Cars will loosen the bolt and slip the overflow bracket underneath before tightening it back down.


  6. Cut ~6 inchesof the silicone line off of the length provided and install it to the bottom of the overflow can.

  7. Drop your coolant bottle down onto the lower mount, the pin should sit into the grommet, make sure not to push the grommet out.

  8. Next, slip the top bracket onto the top of the coolant bottle, and use the two flat headed socket bolts to secure the bracket to the coolant bottle. Then you can tighten up the other two bolts holding the bracket to the radiator support. (Make sure the hood release cable is in the channel before tightening or it may pinch the cable)

  9. With the bracket secured you can now install the cap into the windshield reservoir fill tube.

  10. Remove the overflow hose from the radiator and rotate the fill tube and pop it out of the bracket.


  11. Use the overflow to add fluid to the new COBB overflow. Looking at the dipstick, you want to keep the fill level between the two cuts on the dipstick. Any higher and as your cooling system contracts it’s possible it will spit fluid out.

  12. You can now install the cap for the coolant overflow

  13. Install one end of the remaining length of the silicon hose to the coolant tank and then route it to the radiator. Feel free to trim a little off, make sure it isn’t going to interfere with anything.

  14. You’re all done! Go Out and Enjoy!



Copyright 2024 © COBB Tuning Products LLC. All Rights Reserved. | www.cobbtuning.com