Problem: My Fabia’s temperature indicator light started flashing and beeping at me a few minutes after the engine was started, each time I used the car. The coolant level was fine, and the car seemed to get up to temperature quickly and stay there, never overheating. A quick search of the Briskoda forum revealed that this is a common fault, caused by faulty terminals and/or electrodes in the expansion tank vessel.
Solution: On the VRS models, and possibly others, the electrodes that measure coolant level cannot be replaced or cleaned, so a complete expansion tank replacement is needed. Thankfully these are cheap (about a tenner) and easy to fit. Here is a fitting guide, with photos where necessary:
1) Unhook the loom carrier from the two fixing holding the tank in place.
2) Now disconnect the terminal on the rear of the expansion tank that connects the coolant level sensor to the loom. There are clips on the top AND the bottom of this clip. Don’t force it, if it doesn’t come off easily it’s likely because the lower clip is not being squeezed firmly enough.
3) Remove the overflow pipe (or maybe it’s a return pipe) at the top rear of the tank. This is most easily done with parallel pliers or mole-grips, by squeezing the sprung hose clamp, then easing the pipe off. Make sure you don’t lose the hose clamp in the engine bay. I found it best to tuck the pipe backwards under the strut brace to keep it out of the way.
4) Unclip the vacuum pipes from the vacuum thingy (if you know what this ‘thingy’ is, please leave a comment below telling me, and I’ll put the right name in). The two sprung clips are easy to press by hand as shown in the photo. You might hear a little ‘hiss’ (i did) when you do this. Doesn’t seem to be a problem.
5) Remove the two front nuts that hold the vacuum thingy frame in. The plastic loom support will probably be right in your way for this. If you’ve completely unhooked it (see step 1) you should be able to manhandle the wiring backwards for the right-hand nut, and pulled right forward for the left-hand nut. The nuts have captive washers which is nice, but be sure not to let them drop in the engine bay!
6) Remove the 3rd frame bolt right by the bulkhead. The angle can be a bit tricky and I found that an extension was needed with the socket set.
7) Now to get the frame out, you will need to pull the loom wiring and plastic support thing right out of the way forward. It hooks over the expansion tank socket quite nicely as you can see in the photo. Lift the frame gently off the two front fixings, then pull it towards the front of the car to get the frame off the rear fixing.
8) Lift the frame completely out of the way. I found that if you turn it 90 degrees it sits between the suspension turret and the rubber bonnet seal quite well.
9) Now remove the 2 fixings that hold the tank in. As shown in the photo below, the fixing is a bolt, a captive washer, and a screw all in one. A 10mm socket removes the fixing. Once both are removed, the tank will stay where it is until you lift it out.
10) Now the tank is ready to come out, clamp the bottom hose near as near to the tank as possible (see pic for step 11) with a pair of mole-grips.
Caution: if you clamp it too right you risk damaging the hose, especially with the mechanical advantage that mole-grips give. It’s soft hose, so only needs to be squeezed a bit.
Then siphon the tank into a bottle or something with some tube. I’m not sure how corrosive G12 coolant is, but um.. don’t drink it.. or get it on your paintwork.. or eyes.. or sensitive bits.
11) Now that the tank is empty (more or less) you can use some pliers (parallel or adjustable ones are best for this) to loosen the sprung hose clamp with one hand, while pulling the tank free with the other hand. I found that the hose came off easily once the sprung clamp was very loose. If the hose doesn’t want to come free, it might be best to use a second pair of mole-grips on the sprung clamp, thus leaving two hands free to wrestle the tank and hose apart.
12) If this is done carefully, there should be no spillage. The tiny amount of coolant left in the neck of the tank after it was siphoned should stay in the up-turned hose.
13) Now, fit the new expansion tank by reversing this process completely. Note: If G12 coolant is already in the system, G12 must be used when the new tank is filled up. It’s best to use new coolant, and the OEM pink stuff is readily available for about £5-10 from any VAG dealer.
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