I didn't need any special tools when I replaced my expansion tank, but I did run into a lot of brittle, crispy plastics. Be sure to look at the parts diagram on realoem.com around the tank, especially where it mounts to the plastic pipe fittings below, so you can see what's hidden. For example, on my 2001 330i w/automatic transmission, there's a thermostatic valve between the expansion tank and the mounting plate. It's held in place by some (inadequate) little tabs that break easily, especially when they're old and cooked. If they break, you'll need a new mount plate as well. I don't think this thermostat is present on the manual transmission cars, however. I also remember that, after pulling out all the clamps, the tank didn't come off the 2 lower fittings very easily. I would suggest taking the clamps completely off the tank, then pull up while gently rocking the tank left to right. It should slowly work it's way off, but it may take some patience. Good luck! Ty
Buy at least the tank, the mounting bracket, the filler cap and the coolant level sensor. Return the bracket if you're able to reuse yours, the others are inexpensive enough that reusing them is unwise. The cap deteriorates over time--it may look OK, but if you compare old and new side-by-side, you won't even think of reusing the old. Ditto the sensor. As tbartosh noted, take care to get the correct parts for your car: automatic and manual transmission vehicles do indeed differ in this area (different plumbing). Whether you are able to separate the tank and bracket at all depends on the age and condition of the parts. tbartosh was fortunate; mine were fused solid. It might have been possible to separate them with Herculean effort and the patience of a saint, but at $60 for a new bracket it wasn't remotely worth the aggravation. If yours is over 120-150,000 miles old, hope for the best but prepare for the worst. In any event, it is much easier to remove and reinstall the tank and bracket as an assembly than to try to separate them in the car. One critical precaution: BMW coolant hose fittings mate in one orientation only. DO NOT attempt to twist them to separate them, you can break things. (Forgive me if you already know this.) It's an easy repair, just take care to seat the hoses fully and firmly before you slide in the clips--the O-rings fit tightly and require a firm push. Otherwise you'll be chasing a fast drip the minute you start the car. Good luck & have fun!
Thanks for all the information. I will be buying the mounting bracket, cap and sensor once I get paid. Hopefully it will warm up around here, so I can work on my car.
