what is the purpose of this part?

[BW Jones]

i've notice that some of the vacuum brake conversions use the part shown below and some do not. what is the purpose of the part and why isn't used in all of the conversions?

bw jones

 

[TURBOV8R]

Someone correct me if I'm wrong but think thats an old style check valve.Newer GM's have the valve mounted directly on the master,much smaller and flatter. tan or black in color I think.

 

[BetMinesFaster]

Thats correct, that is the checkvalve, The newer booster mounted units are sleek, much less bulky!

 

[TURBOV8R]

Thats probably why you don't notice them on the boosters,they kinda blend in.

 

[mikestertwo]

Thats correct, that is the checkvalve, The newer booster mounted units are sleek, much less bulky!

It's not a check valve, it's a filter. It's there to keep any debris out of the check valve on the brake booster. I use it on my conversion.

 

[BW Jones]

i just found an informative article in an old GM High Tech Performance magazine regarding the vacuum brake conversion. they claim the part shown above is a vapor trap to catch fuel vapors. it is shown to be used in line between the brake booster's check valve and the vacuum line coming from the vacuum source. 0405htp Brakes 22 Z Photo
anyone have any additional thoughts regarding its usefulness?
bw jones

 

[turbofish38]

Here's another thread. http://www.turbobuick.com/forums/brakes-suspensions-tires-wheels/244269-what-s-part.html

You know I wonder if you really need it. I see a lot of newer cars in the boneyards that dont use them. I'm thinking the filter is a relic left over from the carburetor days and is not really needed on a modern FI motor.

 

[BW Jones]

thanks to each for your input .

extra thanks to turbofish38 for all his recent assistance ....... he is enormously informative and is a valuable asset to the TB community!

bw jones