Changing Radiator

[beautyland]

I need to change my Radiator. B'cos it's leaking thru seams (1995, 525i, E34, Automatic) with 120K miles. Can I use any radiator coolant mix (makes other than BMW). If I need to add water, what is the mixing ratio (50/50) ?

If some body has done this job earlier, any comments, tips are very welcome.

[Torque]

You have to take off the shrub (plastic part around the fan) and unhook all the hoses from the radiator (on auto there is a hose at the bottom for tranny fluid cooling...it wont leak much). Then all you have to do is unscrew the top part and slide it out (it's held on with like 3-4 screws). It's very very simple (at least it was on my m20 engine, so I'm guessing it's similar on m50s).

They recommend Bmw coolant, but any aluminum-safe coolant will work... 50-50 is good, just mix it somewhere and then pour it... dont put one first then the other.

[nshape8]

Go slow...take your time. Make sure the car is cool and has been sitting for at least 4 hours preferably overnight. Unhook the bottom tranny coolant line first and have something ready to catch the fluid (maybe a pint). label the line "bottom return line" then the other tranny line. Place them out of the way making sure you don't kink them. Drain the rad with the drain plug (should either be on side or bottom) looks like a butterfly nut. When you unscrew it make sure you have something big enough to hold all the fluid. Undue the rad cap (it will drain faster). Once drained, remove hoses and let drain the rest of the way. Now, get some plastic and rubberband and cover the holes so you won't get splashed. Should be some bolts on the side or bottom of the rad, loosen these but remember where you took them out of (bolt sizes might be different in other places. See what the clearance is between the fan and the rad if you have enough room go ahead an remove. Once out I would go ahead and remove the fan to prevent possible damage to the new fan. Also, I would tape cardboard to the side which you think you may damege if you have shaky hands. Anyway, take you time and do the opposite of removal. Radiator mixtutre depends on weather condition IMO 50/50 is a safe ratio though. Also, there's a product called waterwetter that drop engine temp 10 or so degrees (nice in the summer months). Once you get it all back together refill the rad and let is sit to make sure no air pockets. You might even crank it over tho circulate it a little. If there's a purge vale this is the time to use it. Anyway, good Luck!

[beautyland]

Thanks to the toruqe and nshape8.
I have changed the radiator with out any problems. First I did not use the purge valve. Engine got overheated, then I have realized my mistake and corrected right away. Thanks for all the tips and help.