Brakes on 1974 E12

Domingo · Post by **Domingo** » Sat May 13, 2017 12:55 pm

After changing the rear brake pads the car run great for the first 30 minutes then the pedal becomes mushy and doesn't block the brakes, feels dangerous.
Any suggestion pls?

RonDwyer · Post by **RonDwyer** » Sat May 13, 2017 8:30 pm

Did you change the fluid and bleed the brakes properly? Master cylinders can also fail. Pads do not cause loss of pedal firmness unless they are made of foam.

Domingo · Post by **Domingo** » Sun May 14, 2017 12:06 pm

Agree, problem appeared after brake disks were aligned.And brake pad for the rear changed.

Bleeding was done properly.

Something the mechanic did wrong? Yes Masters can fail but why would it work the first 30 minutes?

How would I check the Master otherwise?

RonDwyer · Post by **RonDwyer** » Mon May 15, 2017 9:08 pm

Process of elimination.
Check all 4 corners for leaks
Check hoses
Trace lines
How old is master?
Re-bleed brakes with power bleeder, start farthest from master first.

No luck? Replace master cylinder.

bizz · Post by **bizz** » Thu Jun 01, 2017 11:53 pm

LHD or RHD? I replaced the check valve between the manifold/boosters on my RHD E12 and it helped enormously.

Domingo · Post by **Domingo** » Sat Jun 03, 2017 1:46 pm

Problem solved:

It was dust on one of the caliper's piston after taking the brake disk for alignment.

Rear right tire: Left hand Drive car.

Seals ok.

Car brakes fine

Thanks for all the support.