E30 brakes badly - BMW Forum

solanog · 01-22-2008, 10:35 AM

Hi the 1986 320i has new front (disk) and rear (drum) brakes, new pump. My problem is that when I hit the brakes the rear tires lock and the front ones keep spining until the pedal is pressed with much more force.
How can I adjust this? It was the same with the old pump but the old pump was bad since when the pedal was pressed in a hill, for example, after a little while the car started moving until you push further or released it and pressed it again.

Could the brakes be "balanced" so that more power is sent to the front tires or less to the rear ones?

Thanks.

dannyb · 01-22-2008, 11:03 AM

Did you change the pads (front) and shoes (back)? If so did you readjust your shoes?

ldsbeaker · 01-22-2008, 06:41 PM

Maybe you could "bleed" the brakes. Get the air out of the system.

solanog · 01-23-2008, 04:59 PM

Yes, front and rear pads and shoes are new and of good quality. The system was bled. There is no ABS in this car so the system is pretty much straight forward.
Something similar happened to a Toyota pick-up, rear tires locked when braking a little harder than normal or more exactly when pressing the pedal hard and needing to stop in a short distance. The problem was fixed by adjusting a valve that distributed the braking force between rear and front axles depending on the load of the truck or rear level. It lost its adjustment mainly because a leaf from the spring was removed to have a more comfortable ride so the rear end lowered a little, I suppose we simulated a loaded truck with this.
Anyway, I thought this car may have some sort of valve or something that could be used for adjusting the braking force between the rear and front axle.

ldsbeaker · 01-23-2008, 10:25 PM

No. I don't beleive they have anything like that.
YOu might have a bad master cylinder.....

AlpineSixAndSeven · 01-23-2008, 10:44 PM

isn't there a valve that olds the front disks from appying till the drums have started?

solanog · 01-24-2008, 10:17 AM

Quote:

Originally Posted by ldsbeaker

No. I don't beleive they have anything like that.
YOu might have a bad master cylinder.....

I don't know the exact name in Enlish but I think that's what I call in Spanish "main brake pump". I replaced that thing that goes attached to the booster and which has the brake fluid reservoir attached to because when brakes were applied for example in a hill you had to keep increasing pressure or the car will began moving. With the new one that problem is gone but the rear tires keep blocking before the front tires (both with the old and new master cylinders).

saltshaker185 · 01-24-2008, 04:53 PM

i really think you just need to rebleed the brakes or need to adjust the shoes in the rear... just gotta find the missing link...