E300 Eating break fluid... Slowly

[Mickey76]

Hi, this one sounds expensive!
I started getting the dreaded ABS, BAS and ASR lights back on about a month ago when I drove for about a mile but only if I go above about 50mph, abs kicks in at low speeds until lights come on. THEN... BAS light started staying on when restarting car, got 1mile, reached 50mph ABS and ASR comes on. NOW... Early december low brake fluid warning comes on, fluid on min level. Topped up to max.done this 3times to date. Approx 400ml?
Brakes feel normal, no marks on drive of fluid loss. Had car sat a week and no fluid loss, loses only when driving and only very small amount. Fluid looks clean. Nothing obvious underneath car. Could it be BAS unit ,internal leak?
Thanks in advance

 

[Doug1234]

Have a look under the dash ,run your fingers along the brake pedal up towards the servo rod mechanism and feel for brake fluid on the metalwork and also on any sound proofing it would have dripped onto if it is as I suspect escaping out the rear of the servo.

 

[Mickey76]

Had quick look but all dry where I could get to. Will take panels off in daylight to check properly tomorrow. Is that why the car has started steaming up on a morning?

 

[television]

It can go into the brake servo when leaking

 

[Mickey76]

Taken panels off and checked under master cylinder/servo, no leak visible. Is there any way to check for internal servo leak? Will get car on ramps and check everything thoroughly underneath tomorrow hopefully.
Anyone got any ideas what the BAS light has to do with this?

 

[television]

There are BAS travel and pressure sensor in the servo so this could be the problem if no external leaks found.

 

[Mickey76]

Had a check today, everything is wet so a little difficult. Suppose the only way to see if its servo is to keep topping up fluid and see if any fluid comes out anywhere?? The e class of this era certainly isn't mercedes' proudest moment!!:neutral:

 

[television]

The servo tank is air tight,,,perhaps you can disconnect the vacuum hose and see if it is wet

 

[Mickey76]

Am I ok to just pull the vacuum hose out?
Thanks

 

[television]

I am not sure how it is fitted, if no clamps it should pull off

 

[Mickey76]

Super, ta, was just checking as pulling stuff on this usually turns out bad!
Wish the rain would give me a break though!:lol:

 

[television]

Super, ta, was just checking as pulling stuff on this usually turns out bad!
Wish the rain would give me a break though!:lol:

I will check for sure on this,, the rain, dont tell me about it,,,front caliper seized on the V70R

 

[Mickey76]

Good old brute force fix? They're the kind I like! No electrics involved