'88 740 B230K motorway driving coolant leak
 

Hi folks,

I have a 1988 740 wagon with a B230K and I've noticed it is leaking coolant quite severely after I drive on the motorway. It seems to be dripping on the ground from the general area of the radiator. Has anyone had a similar issue or have an idea as to why it only happens after motorway driving?

Most likely culprit is the expansion tank cap and/or overfilling. Should be up to the MIN mark when cold but the caps have a habit of doing that. :(

Make sure you get the right pressure rating, one is 1.1bar/kPa, the other is 1.5bar/kPa or 16 and 23psi respectively. Should say on your existing cap what the pressure is. When fitting, make sure it's done up tight as the pressure can get past loosely fitted caps.

Been keeping an eye on it and I think you're right, overfilling was the culprit. Thanks again Dave! Second time in a row you've sorted me out!