Brake booster hissssssing

[TylerW]

Hey guys.....

I got my '66 300 running and driving. But I have booster problems looks like. When i step on the brake pedal, it audibly hisses inside and the idle gets ragged. Is this accepted evidence that the booster is failing?

Has anyone EVER successfully tested a booster with it off the vehicle? I have another Midland-Ross booster that may be ok(I thought THIS one was the better of the two) but I have going to ensure it works before I swap it or I'm obtaining another. these are both remans, don't know if they are worth sending out to be overhauled.

Thanks.

 

[Big_John]

Power Brake Booster Exchange | Providing Parts for Classic Cars

 

[Davea Lux]

Booster has failed. If you have not done so already, be sure to replace the master cylinder at this time. Boosters usually fail because brake fluid has leaked inside and rotted the rubber parts.

Dave

 

[cbarge]

Good opportunity to go dual master if not done already.
Power Booster Remanufacturers / Rebuilders - John Stuart Power Brake - Hamilton, Ontario, Canada - Since 1946

 

[thrashingcows]

Most likely the inner boot has come loose, or never replaced in the past on a booster re/re. Dust, dirt and crud settle on the brake booster piston and when you press the brake pedal down it drives that dust and debris into the seal. Yup need a new booster or rebuild the OEM one.