300E leaking coolant near water pump
 

Hello board, My 1987 300E is leaking a stream of coolant near the water pump, the water pump has only been on my car for about 6 months. I thoroughly inspected the water pump and the leak isnt coming from the water pump. Could there be a freeze plug besides the water pump that the coolant could be leaking out of? If so is replacing the freeze plug a simple DIY, will I have to remove the water pump to replace this freeze plug? Could there be any other culprits causing this leak? I also thoroughly inspected the hoses and there isnt any leak, only the area near the water pump.


HELP!!!

Reach under the water pump and feel the weep hole. It's about at the 7 o'clock position looking into the pulley. If it's wet, it's the water pump. There's an o-ring between the water pump and block that might be leaking. There's also a back cover of the water pump that can leak. Are you sure it's not the heater hose that goes into the side of the thermostat housing?

I don't think there's a freeze plug anywhere near the water pump. Check out the pics at photos.yahoo.com/tabijan in the 91 300SE water pump album. Might give you some insight.

Check the archives also. Within the last couple of months someone posted about replacing a freeze plug for $70. Might be the same problem as you're having.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

Hello board, I did a thorough examination of the area and I see that the leak is coming from the area where the water pump is attached to the engine block. Do I have to remove the water pump and then add a gasket type sealant to the area?

There's an o-ring between the water pump and the block. It's less than $2.50 from the dealer if you can't wait for FastLane. I used a dab of sealant to keep the o-ring in place while wiggling the water pump into place.

I dismissed the recommended Snap-on tool because I can get to the upper rear bolt with a 1/4" socket arrangement. However, I had to remove the dipstick to use the 1/4" socket arrangement and that allowed coolant to drain into the sump. If the Snap-On tool allows you to get to the rear upper bolt without removing the dipstick, then it's worth the money IMO.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

The FLXM 13 is difficult to find. I couldn't even buy one on the Snap On website, they were out of stock. Maybe they have some now. After going through this myself, I believe the tool is worth the $45 or so.

You can use grease to hold the o-ring in place while fitting the pump and starting a few bolts.

Good luck,