e39 530d showing 'check brake fluid' and red handbrake light not coming off

[happyeaster]

i have just bought the car and when i got it home it came up check brake fluid and the red handbrake light does not turn off when i release the handbrake. i would say they are connected and i have topped up the brake fluid and it is still showing up.

any ideas?

[auaq]

Check the wire/connection over at the brake fluid reservoir.

[KevinMullins]

The "handbrake light" is associated with both the handbrake and the brake fluid, a problem with either will cause it to come on.
Do you still get the check brake fluid message?
Was the fluid actually very low?

[happyeaster]

the fluid was a little low but not much. i topped it up and turned the car on and off and the lights went out as did the check brake fluid warning. have driven 50miles and all seem ok with no warning or loose of fluid.
car is parked up in park mode and will check it soon as i assume in the automatics the brakes are on when you park. if its going to leak it will then

[Spirit Force]

the fluid was a little low but not much. i topped it up and turned the car on and off and the lights went out as did the check brake fluid warning. have driven 50miles and all seem ok with no warning or loose of fluid.
car is parked up in park mode and will check it soon as i assume in the automatics the brakes are on when you park. if its going to leak it will then

Brakes aren't on when you park it. Where did you get that idea?

[happyeaster]

just assumed when you put the auto box into park it applied the brakes.

[KevinMullins]

just assumed when you put the auto box into park it applied the brakes.

No. That's why there is still a handbrake lever.
It's there for emergency needs as well as a general parking brake.

[alpinweib]

just assumed when you put the auto box into park it applied the brakes.

I think when it's in P it locks the transmission, and so the wheels won't turn. I wouldn't trust that if you're on any sort of incline or decline though. Always use the e-brake!

[happyeaster]

yea i always put the handbrake on anyway when i park it, just noticed when it was in park it didnt roll so assumed it applied the brakes.
got it up on the lift today and bleed the brakes and noticed a small leak in one of the brake lines so fitted a new one and its perfect now.

[auaq]

Just to give you an idea, this is the parking wheel gear inside the auto transmission (taken from ZF 5HP19).



The more solid and bigger tooth gear is the parking gear and you can imagine the whole car held stationary at an inclined angle without using the hand brake. It is made out of steel and even then it is pretty strong and durable, and it can take on the weight of the vehicle. However, it is always a good idea to use the parking brake whether the vehicle is at a flat, horizontal plane or at an elevated angle.