Brake Pressure Warning.

[Scotty2]

Getting ready for my 96 Turbo RL service and after having left the car unused for 3 weeks I now find that the brake pressure warning comes on every time I brake but extinguishes as soon as I'm off the pedal. Fluid levels OK. I am aware that this could be the first sign of some problems - accumulator e.t.c. so I am looking for some opinions on likely causes and costs.

Car has done 66k. Oh and with winter coming, I still haven't found any blown fuses (some in the boot) or why my rear de-mist and door mirror heaters don't work? Advice welcomed.

[bergxu]

First thing would obviously be the accumulators. Do you know how old they are?

Any LHM leaks you can see around the brake pumps?

[tonys]

Are you sure that the demisters aren't working, or is it just that they are automatic, depending on outside temperature (IIRC)

[Scotty2]

They didn't work last winter - I only found out they were automatic when asking how you switch them on- I still haven't found a handbook. Should have come on by the time I was seeing -12C !

As for brake pump leaks - nothing visible although I have to put in some fluid every couple of months but no marks on the drive except when it overflows if left to "settle" for too long.

Don't know if they have ever been changed? Not in my ownership of 2 years.

Thanks for the responses though.

[atomicpunk]

Sounds like the accumulator spheres need replacing. This is not unusual as they're a service item.

I had mine done earlier in the year. The spheres were £65 each (there are two) with two hours of labour to remove the old spheres and fit the new ones.

[bergxu]

@ atomicpunk; Yikes! Two hours for brake accumulators?? I watched my guy do mine and between racking the car, lifting it, R&R'ing the two spheres followed by a quick bleed it was about 15 minutes tops. Granted, he's probably done literally hundreds if not thousands in his career, but even doing them myself I couldn't imagine it'd have taken me more than one hour...

[ADP68]

http://www.rrbew.co.uk/Pdfs/Changing%20Front%20%20...
link above

[2woody]

mine had grown a bunch of mould inside the LHM reservoir - could be something else to check.

But I'd change the accumulators as a matter of course

[bergxu]

@2woody;

Now THAT is interesting! Didn't know LHM could harbor mold growth!

Then again, in damp Blighty, anything's possible I guess.

[Batrover]

I had a similar experience with my 94 Turbo R, except it was the 'low mineral oil' warning coming on briefly under braking, and when accelerating with any vigour. Otherwise the car was running fine with no adverse effect on ride or brakes. I took it the 70-odd miles up the motorway to see my specialist, who said it should make the trip no problem, and with my confidence growing, by the time I got there I was going like the clappers.
It turned out to be some leaking seals on a hydraulic pump, which were tightened up in short order, at minimal cost. No biggie after all.

[2woody]

bergxu said:

@2woody;

Now THAT is interesting! Didn't know LHM could harbor mold growth!

Then again, in damp Blighty, anything's possible I guess.

'twas a bit like pond-weed

[bergxu]

Batrover said:

I had a similar experience with my 94 Turbo R, except it was the 'low mineral oil' warning coming on briefly under braking, and when accelerating with any vigour.

Also, even with a leak-tight system (which, by design, they are not) you actually want to overfill the reservoirs just slightly, which will eliminate the "Low Mineral Oil" warning from coming on during hard acceleration.