Mark 7 brake question

hotrodbuilder

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My '91 MK7 takes about 20 seconds for the two brake warning lights to go off when I start it for the first time each day. After that it only takes about 4 or 5 seconds. If I start to drive away before these lights go out the brakes are not good. Is this normal? It seems dangerous.
Thanks for any input.
 
It's fine if they turn off. If they don't, then is when you have to worry. As the car ages, it may take longer for one or both of the lights to go off. This is due to the accumulator becoming worn. It keeps the brake fluid under enormous pressure. Eventually, it may need to be replaced. However, if the lights keep shutting off, you're good to go and it is OK to drive the car before they shut off.
 
Be carefull about those brakes. I can understand the brake and ABS lights coming on for a few seconds in the morning, but its NOT normal for them to come on any other time of the day. That is a sure sign of a weak accumulator. Driving around on a weak accumulator is extremely hard on the pressure switch, relay and even the $900 hydraulic motor!

To understand where I'm coming from, go here: http://www.americanairsuspension.com/BRAKES MK 7.htm
 
skymasteres said:
What do you do If they don't shut off?
You do preventive maintenance on your vehicle such as replacing the brake fluid or "bleeding the brakes".
skymasteres said:
Is it serious?
No but it will lead to something serious really fast. Search here and on the web for <tech article bleed brakes mark VII>.
 
skymasteres said:
What do you do If they don't shut off? Is it serious?

The lights being on first thing in the morning isn't that big of a deal, but if you see the lights on during normal driving....thats when you should start making plans.

The accumulator is there to store energy so that the hydraulic pump only has to run every 3-5 times (normal braking) the brakes are applied. When the lights are coming on, that means the pressure is dangerously low....which means the pump is having to come on a whole lot more than it should. Think about this: If the pump is coming on every 1 or 2 times the brakes are applied, its making an already old system work 2-3 times more than it would normally. That will push old parts over the edge. The actual problem is the accumulator but if its allowed to go, the pressure switch and relay WILL go out also. (BTW, you don't want to have to buy a hydraulic motor=they were $900 back when I was a Lincoln tech=6 years ago)

When it finally decides to go out completely, the brake pedal will be extremely hard and if your not ready for it, could cause you great pains.
 

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