Replacing my ABS module and my Coolant temperature sender I see this this hose rotting out. Looks like it is supposed to carry vacuum but its vacuum carrying days are long gone!
Car seems to run okay, what is the hose?
2002 Xtreme PS PB AT

 

do you have automatic climate control? if not that might be for the HVAC system, iirc its also present on Automatic Climate vehicles but it goes to the PCV cover tap iirc.

 

It's probably 7/32" but I'm sure if you drove it down to the auto parts store, opened the hood, and pointed to it, they could fix you up with the right stuff. It might even be a good idea to buy some etra in several sizes and replace them all, since they're probably all the same age.

 

One end of the hose runs to a nipple under the throttle body cover (pic), It is possibly something to do with the brake because I am getting a whooshing sound when I hit the pedal, but not sure if that sound coincided with me messing with the hose.

Also, in the first pic, where there is a "T" in the hose, the branch on the right is rigid and runs into a hard line or wrapped bunch of wires immediately below. The other branch runs into the fender sheet metal.

 

Yes, it is 7/32. The other two branches look like 5/32," all pretty rotten. IDK why the extra hose to the hard line, so maybe it's a different size.
The black connector on the T looks like a check valve but if it was, it's not working now.

 

It looks like it goes to the canister purge valve. And that does appear to be a check valve. If you have the hose diagram on the underhood decal, it should say what it is.

 

I replaced all 3 hoses, maybe that will prevent a future SES light.
So the vacuum is originating in the throttle area and pulls through the hard line to the canister? I wonder what the check valve was for.

Edit: one of the benefits of replacement was that my HVAC, instead of always coming out the face vents, now comes out floor and defrost vents, as directed by the control ****.