Brake Fluid Replacement

[tamrsoft]

I would like to flush through my braking system with new fluid (since I am not sure when it was last done). Does anyone know the amount of new fluid needed for complete system replacement and the specification of brake fluid to be used. Car is a 2001 E220 CDi.

 

[Brian WH]

I would like to flush through my braking system with new fluid (since I am not sure when it was last done). Does anyone know the amount of new fluid needed for complete system replacement and the specification of brake fluid to be used. Car is a 2001 E220 CDi.

It should have been done at each two year cycle as part of maintenance by MB dealer. Ask them to check your cars records. Not easy to do on a modern CDI due to the electronics.

 

[Dieselman]

Half a litre should be adequate unless the old stuff is very gunky.

Suck the old fluid out of the reservoir before filling, this gives much less contamination. Obviously leave a very small amount so no air enters the system.

 

[nickmann]

When I did my c240 I used about 1.5 litres. I used a pressure-bleeder and just kept going till the fluid was clean. I wasn't trying to hold back and save any fluid, you could probably use less if you are really concerned about it.

 

[tamrsoft]

Gentlemen,

Thank you for the responses. So if I connect a bleed tube to each brake nipple point in turn and pump out (and replace) about 1/4 ltr at each step, then I should have fully bled the system ?

Can you tell me which DOT spec (3,4 or 5) I should use or does MB have their own particular spec ?

 

[996jimbo]

You will know when you've fully bled each part of the system as the fluid will initially come out blackish and then run clear.

The first brake will take most fluid as you'll be emptying the (remains of) the reservoir plus that line, the remaining 3 should be a little less as you remove the old fluid from the individual lines only. In principle anyway. I'm not sure whether ESP or ABS complicates the procedure.

 

[tamrsoft]

Brake Fluid - confused.

Many thanks for all the responses, I believe with the help of these I have the procedures sorted.
The open question is the DOT spec. I noticed when looking under the bonnet over the w/end that reservoir cap had DOT 4+ printed on it. A quick check through the brake catalogue in Halfords stated DOT 5 for most Mercs (1998 onwards), on their shelf they had a litre bottle of brake fluid DOT 5.1 (the most expensive) with the words 'compatible with brake fluid spec of DOT 3 & 4 and contains no silicon'. Yet I have seen definitions for DOT 5 fluids as silicon based fluids. What is the truth, I don't want to use brake fluids that are either out-of-spec or not compatibile with what has already been used.

 

[nickmann]

... I don't want to use brake fluids that are either out-of-spec or not compatibile with what has already been used.

Then for peace of mind buy your fluid from the parts dept of your local MB dealer.