Brake Booster Water Problem HELP!!!

Cosmo and I have had a brake booster/master combo mounted below the floor like alot of guys do and twice, we have had a booster fill with water. They were two different brand boosters and this time the vacuum line even filled with rust.

Now that evertyhing is new again I am wondering how to prevent this from happeneing again. Help!!

kermit

 

by design this is going to happen if you live in a wet climate.


The booster sucks in atmospheric air pressure around the pushrod when you push the brake pedal. Your booster relies on the differential air pressure of vaccum on the master cylinder side and atmospheric pressure on the pedal side to provide the assist.

The only way to stop it is to keep the intake dry. Most OEM manufacturers decided to mount them on the firewall so they can draw relatively clean, dry air from inside the cabin. In your case you are going to have to build a clean air shrould and stop using your car as a submarine,

 

OK, BUT the water is on the master cylinder side and also goes up into the vacuum tube. This would seem to be the opposite of your theory.

Kermit

 

The valve that controls the vaccum on both sides of the diaphram can allow water to be sucked through from the push rod side to the master cylinder side.

You could have a bad seal between the booster and cylinder. Some older systems used an O-ring around the master cylinder to provide this seal. Newer systems use a rubber seal that sits inside a recess behind the master cylinder. That would be the only other place for you to pull water from.

In any event this can only be solved by my previous suggestions, build a shrould around the booster/cylinder to keep it dry and avoid driving through puddles that would submerse the system.

 

If you have power steering, there's always hydroboost too. It will allow you to eliminate the vacuum plumbing.