02-27-2002, 11:29 PM
Join Date: Aug 2000
Location: Austin, TX
Water Pump Success!
Well, I finally got around to replacing the water pump on my '90 300SE. It took me a whole day, but I got it done and NO LEAKS! I did drop a socket behind the pump as I was 90% finished. My magnet was too big to pull it out, I don't know how I got it out, but after 45 minutes of Zen and Yoga breathing,cussing and prating I got it.
The most difficult thing was getting the top bolt off the pump under the intake. I used a combination of 1/4" wobble extensions to get at it.
I went ahead and got a Mercedes pump for $100 and MB coolant T-stat, hoses ect. All in all, I spent about $150, the shop wanted $500 and it's worth it if you don't have the time/patience to DIY. Having done it, I think I could do it again in about 4 hours, (not that I'd want to).
Thanks to all who posted assistance, especially CHOWPIT for the CD instructions, they were a big help.
1. Disconnect battery
2. Remove Shroud
3. Remove Air cleaner housing
4. Loosen tensioner and remove belt
5. Drain/flush system
6. Remove Water pump and Power steering pulleys
7. Remove upper/lower radiator hoses
8. Loosen steering pump and swing out of the way
9. Remove belt tensioner (I didn't remove the bracket)
10.Disconnect the return tube on top of the pump.
11.Unbolt and remove the pump (easier said than done)
12.Carefully clean surfaces on block, apply small amount of grease to mating surfaces.
13.Assembly is reverse
Re-filling tip: make sure heater is set open, pour coolant into opening of t-stat until completely full, then place t-stat and cover, fill resivoire start engine let idle, check for leaks and heat.
91 300E 120K
90 300SE 275K (sold)
92 BMW 525iM 120K
90 BMW 525iA 175K
85 300D 175K (sold)
84 300SD 245K (sold)