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post #1 of (permalink) Old 13th June 2014 Thread Starter
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Brake Problem Diagnosis


My brakes feel very soft and weak on the Laguna MK2 1.9DCI. Kind of like they are manual only with no power assist.

Firstly the brake fluid is really dark and dirty. How can I clean the brake fluid filter? I have new fluid to go in too once I know the system is right.

I suspect the vacuum system has a leak or problem. Can anyone advise the best way to diagnose the area of trouble?

I note that the butterfly actuator only stays closed for about 5sec after the engine is switched off. I read in another thread it should be more like 20sec if there is a good vacuum and no leaks.

I took off the pipe at the vacuum pump end that goes to the master cylinder and there is vacuum sucking my finger so I presume the pump is good, though I guess it could be working but weak.

Any simple way to check if the leak is the master brake cylinder itself?

I've taken some pictures and I'd be grateful if someone can tell me what the blue, red and green dotted parts are?! I've added a few other images just in case it helps.

Currently in ssashton's garage:
Laguna II 1.9dci

Last edited by hondo; 13th June 2014 at 02:35 PM.
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