Do you think this will work....?

[slocrow]

I noticed that recently my power brakes had become hard to push. After investigation I found a small 2" hairline crack around the check valve boss that extending down slightly on the plastic booster. I'm wondering if "you" think that JB Weld might repair the leak and return & hold vacuum. Thanks, Frank

[wayne petty]

I noticed that recently my power brakes had become hard to push. After investigation I found a small 2" hairline crack around the check valve boss that extending down slightly on the plastic booster. I'm wondering if "you" think that JB Weld might repair the leak and return & hold vacuum. Thanks, Frank

silicone applied once cured is much more flexible..

try some of the ultra grey.. or use some of the other colors available.. get artistic.. draw a sun burst pattern around the grommet to hide the cracks in plain sight..  

do not use spray cleaner directly on the surface... you might get it inside the booster.. wipe with some on a clean shop rag after a little wire brushing.

do you have a filter in the line like GM cars and trucks use...

the filter is actually a carbon canister to catch any fuel vapors from the intake from migrating into the power booster and ruining the diaphragm.

i have had those carbon filled devices clog and reduce the flow to the point where the booster takes 30 seconds to build enough vacuum to assist on a start up....  hard brake pedal on start up is a weird but not uncommon power brake complaint...

[slocrow]

I noticed that recently my power brakes had become hard to push. After investigation I found a small 2" hairline crack around the check valve boss that extending down slightly on the plastic booster. I'm wondering if "you" think that JB Weld might repair the leak and return & hold vacuum. Thanks, Frank

silicone applied once cured is much more flexible..

try some of the ultra grey.. or use some of the other colors available.. get artistic.. draw a sun burst pattern around the grommet to hide the cracks in plain sight.....

Thanks for the response Wayne. A friend also suggested a more flexible material. I was looking at the ultra copper for its heat resistance characteristic (+700).
I've included a couple of pics of the damage and have already drilled a couple of 1/8th "stop" holes at either end of the crack. 91 Vette, L-98 and it get's hot under the hood.
Do you think the gray will do the job?  Frank

[wayne petty]

i would also look for Broken motor mounts.... something pulling hard on that vacuum fitting...

perhaps the vacuum hose routed the wrong way...

or over the wrong item... when the clamshell hood closes.. looks like its being crushed by somethings...


they also make an Ultra black silicone...  that would blend into the black cover...  you do realize that you are going to need to replace that power brake booster soon...



Chevrolet 1991, Corvette, Brakes, 1990-1991   Y BRAKE PEDAL & MASTER CYLINDER MOUNTING   (1Y04-024)

looks like booster shown as #2 is for the LT5 version and #16 is for the L98 version..

[Jokester]

Why not just replace the booster?  These are your brakes, man.  You don't buy a parachute based on price.

my 2¢.

.bjb

[slocrow]

Why not just replace the booster?  These are your brakes, man.  You don't buy a parachute based on price. my 2¢.
.bjb

Jokester, It's not a price thing as I intend to replace the booster when I find the correct replacement. This is just temporary, kind of like having a hangglider ready while the parachute is being replaced. Not perfect but should get you there. After all it's the power assist and not the brakes we're talking about. I'll be using that lead foot on the middle pedal if it gives way, like I've been doing. Thanks, Frank

[slocrow]

Wayne, the mounts good. I think somebody leaned on it heavy while in there for another reason. Not happy but the gray matter is doing the job. Frank