Brake Light on

[qseven]

Hello everybody i made some search for this problem with no success.
Since few days i have strange problem with red brake light on instrument panel that comes on for one second every time i use the brake pedal and then goes off.
Car seems to brake normally while driving but in neutral gear at 0 km/h if i push the brake pedal long and with force till his full travel i get error about power brake failure on cental pedestal display.
It seems i have something wrong with power brake vacum line.
Do you have any suggestions before replacing parts?
Thanks for any help
BR Riccardo

[Timm]

That sounds like classic symptom of a failed brake accumulator (often called a brake bomb). As you get a long pedal at tick-over it indicates that there is no pressure on the accumulator. A test is to open the power steering reservoir with engine NOT running, check the fluid level and then press the brake pedal a few times - the fluid level should rise, if it doesn't then the accumulator is not storing pressure.

[qseven]

Thank you for your help Timm.
I can confirm that my brake accumulator has gone because i feel the pedal very hard in case of emergency braking.
I don t know if it will be easy to find a spare part or a good used one.
Do you have any suggestion where i can find one at an affordable price or if i can refurbish mine?
Thanks again for your usefull help.
Riccardo

[qseven]

Anybody know where i can find a new or used accumulator?
Thanks for any help

[Wuffer]

https://www.ebay.com/itm/BMW-90-97-7...jjXg:rk:1:pf:0

[NICO57]

https://www.oscaro.com/fr/search?q=34331162056

[qseven]

Thank you for help but the accumulator seems to be unavalaible and out of stock anywhere.
Maybe i have to find a good used one or refurbish mine if it is doable.

[TxGR8White]

Anybody know where i can find a new or used accumulator?
Thanks for any help

Do yourself a favor and buy a NEW one, used ones usually won’t last, especially if you don’t know it’s hostory. These cannot be refurbished.
AMAZON has several listed right now.

[shogun]

In the worst case, that you cannot get a new one: in case the bladder is still o.k., it is possible to refill gas, some people have done it on the German 7-forum on the brake with 1 connector, as this is NLA, they added a re-fill valve, see my pic in post # 38 https://www.bimmerforums.com/forum/s...ght=brake+bomb
The Citroen owners do that too and there are even services for testing and re-gassing http://www.citroencarclub.org.uk/dru...a26ab55543664d
https://www.youtube.com/watch?v=l8KaM9bpyu0

Desmopan diaphragms for LHM spheres for the Citroen
These type of spheres were used on the ID and DS models but also on the Citroen SM, the Maserati Merak and the Citroen CX Break/Wagon rear spheres
https://citroen-andre.com/new-diaphr...heres/?lang=nl
http://www.citroenclassics.co.uk/hydraulics.php
http://www.czasopisma.pan.pl/Content...per.%20pdf.pdf
https://shop.citroenclassics.co.uk/r...arge-937-p.asp

[qseven]

Oh Thank you Shogun thats a great new.....i own a Citroen DS 23 and there is a place not far from me where they do accumulator recharging.
I remember i was there during my DS restoration and i will give them a visit again to find out if they can do something for me.
I do agree with TxGR8White but i cannot find any NEW avalaible for less than 400 euro.
thanks for help

[NICO57]

Other solution

https://www.originparts.de/index.php...am=34331162056

Attention, choose the right price of delivery to 16 euros

[shogun]

they do not have it on stock, see details: Delivery time to us: If available at BMW then approx. 7-10 working days! 34331162056
!!! We are not able to order or deliver not available or canceled parts !!! You will find delivery time for available and not canceled parts at the Motor Companies in the article-description.

Just found in Germany a specialized shop for reman spheres for the Citroen, they mention on their website that only for the Citroen C5 there are abt. 20 different membranes available, they also update the spheres with refill adapters
http://federkugel.de/
They have already serviced more than 10000 spheres. Have asked on the German forum if someone can contact them to check if they also could provide such a service for BMW brake bombs as well as the SLS/LAD ones.

Do not buy old stock ones or used ones. When the brake bomb with one connector was NLA, someone on the German forum contacted ATE, they told him the production machines have been scrapped and they also scrapped all new brake bombs in their stock older than 5 years, as every years the 'bladder' loses some % of the gas.