For the last probably two months I have had an annoying popping under the dash. It is usually right after first starting the truck and then is random while driving and after turning the truck off. I checked the wiper delay module thingy and still heard the noise. It stops if i lightly push the break pedal and starts again when i release the brake. I'm leaning towards it being a bad booster, its a reman less than a year old. I know people have had bad luck with the reman units but I've never had a booster go bad and make this type of noise.

Any ideas?

 

Id use a hose or tube to reach up and isolate listening to the area its coming from

 

Watts your volt meter doing when these pops occur? Take a look up there at night and look for flashes.

 

Volt meter is fine, looked under the dash at night for flashes and see nothing.

 

cowl crack noises??

 

Don't think so. It has a rhythm to it. Not speed or rpm related. And stops after a bit.

 

Have you tried changing the air selector on the heater while its doing the sound? That moves with vacuum and could be related to the brake booster.

Any auto resetting circuit breakers in the fuse block?

 

I've held the fuse box while its doing it. Can't fell it coming from anything there. Haven't tried the selector, but i will.

 

Old, no longer used but still hooked up security module? BTDT

 

Guess that's possible. I'll have to look up in there some more.

 

Nobody ever heard a booster do this? They are a pain to change and i hate throwing parts at a problem.

 

boosters will leak vacuum, hissing noise

 

That's exactly what I'm used to with them. Hissing or a woosh when you press the brakes

 

ive have the same noise. i always figured it was the dash plastic expanding from my heat being on..