Hi. I was hearing a noise from my engine and traced it to this rotted vacuum hose. Any idea where it goes? Goes behind the abs module and don’t see where it is supposed to come out.

 

What's it hook to up above? There is one that runs from the 4x4 module down below to the 4x4 somewhere.

 

There is a vacuum reservoir back in the fender so that when under load the vacuum acuators work.

I have a link in my sig file thst that describes the system for a Blazer with the 4-button transfer case.

With a Bravada, you won't have any hoses for the transfer case.

It is a good time to replace all those hose in the engine compartment.

 

Thanks @Walleye Hunter and @christine_208!

I actually found your write up on google this morning when I went to research it more. Very helpful with all the dimensions and sizes. Thank you! I was wondering what was meant with the transfer case vac line as I know for a fact that mine doesn’t have one. Only a breather hose. Makes sense now that you mention that the blazers are manually actuated. Funny how those are both pneumatic and mechanical. I was picturing it was simply electric clutches like mine.

so, what does the vac system actually run on mine, just the hvac selector actuator? I have noticed that the air does come and go on its own. (Sometimes the ac compressor doesn’t want to come on and/or the blower motor fades in and out). I am resurrecting/restoring our old Bravada and doing much overdue maintenance.

I just finished replacing the spark plugs/wires/distributor cap/rotor from original and I feel like I wasted my time. The spark plugs were near perfect. .6mm-.7mm, cylinders still have crosshatching, wires were still strong and didn’t fall apart at the boot like almost new aftermarket ones I replaced on my other vehicle. Believe it or not, the plastic jackets on the wires were all perfectly intact and I reused them. Even the distributor cap was near perfect, with slight corrosion on the sides of the pins. The only sign of wear was on the rotor in that the car edge was slightly rounded and dark. Never had a misfire or hesitation in 230k miles.

Even the rear diff fluid was remarkably clean. Transfer case fluid was noticeably blue as well.

I also went and replaced all the front end components (tie rods/pitman/idler/control arm bushings/ball joints/sway arm connections. All were amazingly perfect except one ball joint had a torn boot. I’ve never greased any of it, maybe once in 10 years.

It’s my wife’s first car and my favorite of our three. GM really knew how to build them with quality parts. A real solid vehicle.

In fact, all I’ve ever had to replace was the radiator/water pump/heater core, ac clutch (used all new components while I was at it), lower intake gaskets, brakes and tires of course, and her dad had the transmission rebuilt 8 years ago. This year, I also replaced the torque converter and installed a shift kit in hopes that it would last us a long time.

Not bad for a 22yr old car. They surely don’t build them like this anymore!

 

Oh good. I'm glad ypu found the write up. I posted it in hopes it would help people.

As for what systems need vacuum, for a Bravada it might be only the actuators for the HVAC system.

Sounds like you have a good Bravada.

I've had to replace my remote oil cooler lines and rebuild my AC system.