PeachParts Mercedes-Benz Forum - View Single Post - Where is engine block coolant drainage bolt?

tcane · #10 05-06-2002, 05:45 PM

The cooling system holds almost 3 gallons (11.6 qts.). The radiator holds about 3 - 3 1/2 qts. You will still have 3 + qts. or so in the block with the water pump removed and the rest in the hoses and heater core. You can drain more out of the block by raising the rear end - the more old coolant removed the better, esp. if it has not been drained in a while and esp. if you're changing to the 5 yr./100,000 antifreeze. HGV suggestion to run fresh water and then drain is a good one, esp. if you don't know when the last time the coolant was changed or if the old antifreeze in it was the new high mileage type (old formulation needed R&R at 2 yrs./24,000 mi.).

The water pump bolts are torqued to 8 ft. lbs. or so (96 in. lbs) in a criss-cross pattern. Gasket sealer is not a must, but I use a small amount of high temp silicone (Ultra-Copper by Permatex) because the engine surfaces are not new and some variations in the gasket contact surfaces may exist which could lead to leakage (I want to stress, a very small amount of silicone spread thinly and evenly). Make sure the gasket contact surfaces are clean of all the old gasket material and I clean with isopropyl alcohol. In the old days (or was that the bad old days?!?), grease or oil was smeared on the new gasket to soften it to seal better and also hold it in place (good idea if you don't want to use silicone). The new fan belt will stretch a bit in 15 min. or so of running, so it will need to be retightened (do not over-tighten to begin with because you can ruin the bearings in the water pump and/or alternator).

Good Luck!
Tom