Brake Booster Hose

I have a 99 XJ with around 148K that makes the nastiest sound on start-up and shortly thereafter. Sounds like a diesel with all the knocking and tapping. I've seen where this could be a Flex Plate or carbon build up and to use Seafoam. I have read a ton of seafoam posts and will try that.

But my question is where exactly (pic would be great) is the brake booster hose? I've read where to use it in the intake by removing the air hose and pouring into TB, but also to add through the Brake Booster Hose. So where's that hose located?

I want to learn as much as I can but every time I type "What is ____" into Google, all I find is where to buy parts. How did you guys find out where and what things like Lifters, rods, etc. are? Thanks in advance.

the brake booster hose is off the driver side firewall, there's a big black plastic bit with a hose running from it to your intake manifold. Unplug this and use it to suck the Seafoam through.
I would personally use an entire can of Seafoam on it, just stick your thumb over the brake booster hose to feather the RPM's a bit as your engine sucks it up. I find you want the engine to bog a bit as it's sucking in the cleaner, but keep a constant flow going. As the can get's empty, let it really build up on cleaner to the point that it's about to stall out. Immediately shut the engine off, re-install the brake booser line and let it soak for at least a few hours, overnight if convenient. The 5 minute garbage they recommend on the can doesn't work as well IMO. Fire it up and give it some wide open throttle blasts to clear the smoke. Hope the neighbours don't mind.

It should be a short rubber hose between the intake manifold, and the brake booster (that big thing that the master cylinder is attached to). It will be the only hose on the booster, IINM.

Is it better one way or another, pouring through the BBVL or disconnecting the air hose and pouring into TB? Thanks a ton for the Booster tutorial. Really appreciate that.

I disconnected the line at the booster, and slowly poured it in there- too much and you'll stall the motor- also, pulling that line raises the idle, which helps keep it running during the process. That was how it was recommended to me, and worked well.

Perfect. Thanks again, I will be foamin' this weekend!

Something else recommended (I didn't do this, since I knew I was going to be replacing the cat anyway), was to pull the cat and exhaust after you treat it, but before you start it- so if there were large chunks of crap being blown loose, they won't clog the cat and create more issues. That's about all I can think of.