brakes Hard Brake Pedal

[Jerry0721]

Just recently my brake pedal has gotten very "hard". I still have brakes, but not much. Any suggestions?

Thanks, Jerry

[ryansti]

Most likely the brake booster has failed. Happened on my old 74.

[ray_]

See if you lost vacuum to the booster too...

 

GL,

[M3M3]

Check hose between carb and booster.

[Mike Self]

I'd check the hoses before suspecting the booster; they're pretty long-lived. 

 

The hose that connects the brake booster to the intake manifold is in two pieces--booster to check valve (long), and check valve to manifold (short).  Leaks are hard to detect because of the cloth covering--the rubber can crack underneath without your noticing so inspect carefully. 

 

The long hose wears where it's clipped to the OEM air cleaner can; check that spot even if you have an aftermarket air cleaner.  The short hose is always bent to one side, and is usually the one that fails first; replace it with the same hose from an E21 320i; it's moulded with a bend in it so won't be stressed. 

 

Don't forget to reinstall the check valve in the correct direction (marked by an arrow)

 

cheers

mike

[Dev02]

Check your fluid level. If it's low, and you do not have fluid in your pedal box, it could be leaking into your booster. When your booster dies, or your hoses/check-valve to your booster do, you get hard brakes.