Pelican Parts
Volkswagen Parts Catalog Accessories Catalog Volkswagen How To Articles Volkswagen Tech Forums
Call Pelican Parts at 888-280-7799
View Recent Cars  |Shopping Cart Cart | Project List | Order Status | Help
Bookmark and Share

Pelican Technical Article:

Coolant Expansion Tank Replacement

Steve Vernon

Time:

1 hour1 hr

Tab:

$20 to $80

Talent:

**

Tools:

Pliers, T25 Torx, Philips screwdrivers

Applicable Models:

VW GTI (2006-09)

Parts Required:

New expansion tank, coolant

Hot Tip:

Replace the tank with the engine cold

Performance Gain:

A major cooling system leak fixed.

Complementary Modification:

Flush cooling system

Over time, the coolant expansion tank tends to turn yellow, become brittle and form micro fractures and sometimes leak. When the car warms up, both the heat and pressure of the coolant starts to attack the weakest point of the tank, eventually causing it to fail and the car starts leaking coolant. The good news is that the replacement tank is relatively inexpensive and can be changed in less than an hour.

Take a look around the coolant tank. In some instances, you can instantly see it has been leaking. In others, you may only see a faint trace of coolant weeping/staining the crack or seam. It's important to tackle this problem as soon as possible.

You do not need to drain all the coolant from the vehicle just drain enough so that it is below the coolant reservoir. If the coolant in the car is new there is no reason to replace it as long as you drain it into a clean container. Coolant is expensive and not to great for the environment so if the coolant in your car is good, try and save it to reuse. If your coolant is old this is also a good time to perform a flush and install new coolant. Please see our article on coolant flush for additional assistance.

If you are just replacing the coolant expansion tank use a turkey baster of fluid pump (red arrow) to remove the coolant from the tank.
Figure 1

If you are just replacing the coolant expansion tank use a turkey baster of fluid pump (red arrow) to remove the coolant from the tank. There may still be a little spillage when you remove the lower hose so be prepared for it.

The sensor harness removes by squeezing it in and pulling it straight off the reservoir (red arrow).
Figure 2

The sensor harness removes by squeezing it in and pulling it straight off the reservoir (red arrow).

Use a set of pliers and carefully remove the overflow hose (red arrow).
Figure 3

Use a set of pliers and carefully remove the overflow hose (red arrow). The nipple on the reservoir can get brittle and break off in the hose so work gently.

Remove the wiring harness from the two clips (red arrows) and set it on top of the tank.
Figure 4

Remove the wiring harness from the two clips (red arrows) and set it on top of the tank.

Remove the two T25 Torx screws (red arrows) holding the reservoir to the mount in the engine compartment.
Figure 5

Remove the two T25 Torx screws (red arrows) holding the reservoir to the mount in the engine compartment.

Lift up the reservoir and remove the lower hose (red arrow).
Figure 6

Lift up the reservoir and remove the lower hose (red arrow). Watch for any remaining coolant that may spill out.

The new reservoir comes with sensor already built into it.
Figure 7

The new reservoir comes with sensor already built into it. There are markings on the side of the reservoir for the fluid level (red arrow) and type of fluid (yellow arrow). This is made for the G12 coolant. Make sure to check with your owners manual on the type of coolant used in your vehicle and do not mix them. Installation is the reverse of removal and don't forget to top up the reservoir.

Make sure to check the cap on the tank for any cracks or corrosion.
Figure 8

Make sure to check the cap on the tank for any cracks or corrosion. The tank is pressurized and the cap must make a tight seal for the system to function.

Bookmark and Share

QUICK LINKS
About Us
Careers
Pelican Parts, Inc.
1600 240th Street
Harbor City, CA 90710
Order Online or Call:
888-280-7799
CONNECT WITH US
NEWSLETTER
Sign Up for Pelican Pit Stop News & Special Offers
Page last updated: Fri 6/23/2017 02:38:41 AM