635csi brakeing problem

hello all! my 635csi brakes fine when pressure is applied for normal braking needs. however, when fast hard braking or quick and hard pressure is applied to the petal it is very stiff and does not descend to the normal slack of the petal and most importantly only gives about 50% of the normal braking power. This makes brakeing in emergencies very dangerous. This model does have ABS. please help with any info. Thanks!

hello all! my 635csi brakes fine when pressure is applied for normal braking needs. however, when fast hard braking or quick and hard pressure is applied to the petal it is very stiff and does not descend to the normal slack of the petal and most importantly only gives about 50% of the normal braking power. This makes brakeing in emergencies very dangerous. This model does have ABS. please help with any info. Thanks!


I also have an 88 635csi with the identical problem. I've had mine for about a month. it has 111,000 miles. Has anyone responded to you message????? I am looking into replacing the brake hoses with stainless braided lines

I would ask about the brake pressure accumulator, it is the round ball under the master. I believe this may be the cause, but ask around first.

brake pressure accumulator was the problem. i replaced this and back to normal. thanks for the responces!