95 S-420 maintence questions
 

How is the correct way to flush and replace radiator ? Is there a block drain on this MB? Are there issues on how to refill in order to have no air pockets ?

Can a DIY do a brake fluid flush and replace with and assistant pressing the brake pedal OR is pressure bleeding required on this model. I had trouble with my older 300E and had to have a shop use a pressure bleeder in order to get all air out of brake system. What method is best. I don't have a pressure bleeder yet.

DanielW

flush and replace radiator
 

The way I flush mine is open the drain on the RSF bottom of radiator allowing the fluid to start draining. Then I insert a water hose in to the expantion tank and turn it on slow so it will not flood out. Allow the car to idle for 10-15 minutes or until the water runs out of the plug clear. Turn off the hose and allow the radiator to drain, close the plug and fill with a 70/30 mix. 70% water, 30% antifreeze. Depending on your climiate you may need to add a little more antifreeze. Check with a gauge. DO NOT fill 50/50.

Brakes, have a professional do this for you!

It's been my experience that you will not need to flush the cooling system if you avoid using tap water. The worst thing that you can put in your cooling system is tap water which could contain all kinds of junk.

My last Mercedes was 18 years old when I sold it and there was never a problem with the cooling system. I simply drained all the coolant I could get out of the system from the drain on the radiator and refilled with a 50/50 mix of distilled water and MB coolant. I've continued this approach with my 13 year old 300E and it runs quite cool in the heat of Arizona summers.

In very hot climates you could use a bit more water (55/45) but if you go too far you will then wind up with water pump problems because you will not get enough lubricant and other additives from the coolant mix.

I usually drain yearly because it's so cheap and easy to do.

Your brake system can wait until you get a pressure bleeder.

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

I went to a brake seminar held by a Mercedes dealer in Minnesota and there were a couple of things that I remember.

1st, if the car has ABS, the brakes should be bled with a pressure of around 29 pounds. This requires a pressure bleeder.

2nd, when the dealership stopped using the old two man, pump the brakes approach to bleeding brakes, they no longer had to replace master cylinders. In other words, almost all the master cylinder problems they had they caused themselves by pushing past the normal wear point in the master cylinder.