Baffling E430 brake problem.

[Bob Cash]

New member. Trust I am posting in correct area.
I bought a 2001 E430 three years ago. Great car. Two mots no problem. This time failed only on excessive brake pedal travel.
Garage bled brakes. Worked a couple of days only.
Replaced master cylinder. Tried mot. Falied same problem and they said mc must be faulty.
Second master cylinder fitted. Still failed. Garage knew about bench bleed and pressure.
Fitted servo. Problem still there.
Although unusual, can't be unique. Anyone experienced this or any advice please?

 

[DREAMER NO2]

Welcome to the forum . Can I ask , do you loose any brake fluid ? If so you may have a leak on one of the cylinders .And without removing the wheel and checking them out you wont find it . Also low material on the brake pads could be some of the problem, along with discs under size due to wear .Something else comes to mind .The flexi pipes might not hold up to the pressure. And as you push the foot pedal down it will expands the hose like a baloon [ just for example ] . Reading about these problems, i find that if air is in the ABS system it will take some moving . Another place to look, is the foot pedal for leaking fluid inside the car . Good luck hope you find it soon. But keep looking in others will help you .

 

[Bob Cash]

Welcome to the forum . Can I ask , do you loose any brake fluid ? If so you may have a leak on one of the cylinders .And without removing the wheel and checking them out you wont find it . Also low material on the brake pads could be some of the problem, along with discs under size due to wear .Something else comes to mind .The flexi pipes might not hold up to the pressure. And as you push the foot pedal down it will expands the hose like a baloon [ just for example ] . Reading about these problems, i find that if air is in the ABS system it will take some moving . Another place to look, is the foot pedal for leaking fluid inside the car . Good luck hope you find it soon. But keep looking in others will help you .

Thank you for your response.
I should have been clearer. The most baffling part is there has never been any loss of fluid, inside or out.
Ballooning has been checked and pads and discs are in good condition.
I'm not mechanical but there hardly seems anything else remaining which could be at fault.
I've had a stroke and just received a grant o £1,300 to have car adapted so don't wish to have to scrap car and have unit transferred.
I decided to pay £59 for half an hour diagnostic check by Mercedes specialists. They spent two and a half hours checking and could not trace. (They were kind enough not to charge me anything.)
At a loss.

 

[DREAMER NO2]

Right i am stuck and i know what to advise you to do. Other than go to another garage, and have the system flushed and bled. Fit a set of 4 auto bleed valves to make it easy for you to do a bleed on your own .

 

[Bob Cash]

Right i am stuck and i know what to advise you to do. Other than go to another garage, and have the system flushed and bled. Fit a set of 4 auto bleed valves to make it easy for you to do a bleed on your own .

Yes. Very strange. No one has a clue but thank you for your consideration.

 

[star]

210's are known for a soft pedal when stationary, if you used the same pedal travel when driving, you would feel it. Is the pedal soft with the engine off and the vacuum emptied?

 

[DREAMER NO2]

Bobcash, Stars, above post should know about this problem .They have a garage and this must be a known thing with your 210 . Take it to another test station .

 

[Bob Cash]

210's are known for a soft pedal when stationary, if you used the same pedal travel when driving, you would feel it. Is the pedal soft with the engine off and the vacuum emptied?

Thanks. Remember it is E430. Pedal is reasonably soft when stationary. Driving seems not too bad but when I push harder it does travel a lot. Also, it has been beld at least five times and there is always loads of air. Fluid looks like milk. However, fluid level never goes down and no sign of any leak.

 

[Bob Cash]

Bobcash, Stars, above post should know about this problem .They have a garage and this must be a known thing with your 210 . Take it to another test station .

Thanks. I may take it elsewhere. I've had a stroke and car fitted with £1,300 adaptation so don't want to have to swap with another car. I could not carry out any work.

 

[V6Matty]

Where are you based Bob?

 

[Bob Cash]

Where are you based Bob?

Edinburgh. Took car to Mercedes experts at Newbridge. Two and a half hours could not trace fault.

 

[DREAMER NO2]

Must be water or condensation in the lines to be a milky colour. Has the brake system had any other work done on it . Water wont bleed out so easy as fluid will . Still say it wants a full fluid flush .

 

[Bob Cash]

Must be water or condensation in the lines to be a milky colour. Has the brake system had any other work done on it . Water wont bleed out so easy as fluid will . Still say it wants a full fluid flush .

I have not had any work or problem in three years. Remember, I know nothing about mechanics and understand what you say. I will pass on comments to garage. Thanks.