Kang61
5/4/2008 12:29:21 PM
When the front two pads were changed, I noticed the brake pedal has gone soft and spongy. Tried bleeding all FOUR wheels a number of times, but still no joy. No sign of oil leaks anywhere. With the engine running, the pedal is soft (can be fully pressed) and after 2/3 pushes it goes stiff to half way and then the pedal begins to slowly depress to the bottom again under pressure.
Everything was fine and working before they were changed.
Can anyone help, many thanks in advance.
ohlord
5/4/2008 1:31:32 PM
What model?
w210 need to be pressure bled,take it back to whoever did the brake job.They got air in the system.
ohlord
boycbronco
5/5/2008 6:43:38 AM
If you're not seeing any leaks at the wheel cylinders or air in the line, then the master cylinder has likely gone bad. Not the first time I've seen that happen when working on other brake components.
snanceki
5/5/2008 11:01:41 PM
Hi Kang61,
Welcome.
I assume from your post that the pedal feel was OK BEFORE the pads were changed.
Did the person who changed the pads disconnect the hydraulic lines/hoses?
There is no need to do so.
If the lines were disconnected then air has got into the system and due to the ABS system etc the procedure to bleed the brakes is not as straight forward as you might imagine.
If the lines were not disconnected I suspect that the new pads (sure they are the correct type?) may be contacting the "wear lip" around the edge of the rotor before beginning to touch the main surface of the rotor.
This raises the issue of whether the rotors are in good condition? Were they checked for minimum thickness?
The "wear lip" problem is more likely if you are using non MB OE pads which although they will fit the caliper MAY NOT have exactly the correct shaped pad area thus allowing the pad to contact that part of the rotor which previously was not part of the braking path.
Hope this helps,
Stuart.
