What is this part?

[aaldape]

So I'm in the process of fixing some of the little things on my 1988 suburban, and cannot identify a specific part that I was hoping to get some help with.

The piece is located behind the dash, on the right side of the steering column. It is a black plastic cylinder with threads along the entirety of the exterior. It is connected with a sort of barbed port to a rubber hose that I can't seem to follow far enough to ID. Inside the black plastic piece is a white plunger/actuator that is spring loaded. When the plunger is depressed, the barbed port closes and no air can pass through, and when the plunger is in it's "natural state," air flows through the port freely.

It appears like it should be mounted in some sort of threaded insert, but I really just don't know WTF it is... Any help is greatly appreciated...

Here's the beast, just for fun

 

[frankin5]

do you have cruise control, that works. It might be the brake release to disengage the cruise.

 

[Slickburban]

So I'm in the process of fixing some of the little things on my 1988 suburban, and cannot identify a specific part that I was hoping to get some help with.

The piece is located behind the dash, on the right side of the steering column. It is a black plastic cylinder with threads along the entirety of the exterior. It is connected with a sort of barbed port to a rubber hose that I can't seem to follow far enough to ID. Inside the black plastic piece is a white plunger/actuator that is spring loaded. When the plunger is depressed, the barbed port closes and no air can pass through, and when the plunger is in it's "natural state," air flows through the port freely.

It appears like it should be mounted in some sort of threaded insert, but I really just don't know WTF it is... Any help is greatly appreciated...

Here's the beast, just for fun

I think that goes to the FLUX CAPACITOR but i might be wrong LoL when installing my radio i think i seen tht to i guess ill keep checking this thread to find out for myself

 

[Blue85]

It should mount to the brake pedal bracket. It probably threads into a clip, which lets you set the depth so the plunger strokes when you push the brake pedal.

 

[tRustyK5]

Yep, that's the brake light switch.

 

[aaldape]

Thanks dudes, I appreciate the quick answer and wealth of knowledge on this site. I'll take a look this evening and see where it should mount. I think I must be missing the mounting clip, since it was free-hanging when I got in behind the dash...

 

[Russell]

There will be a second port just beside your brake light switch that it will fit into... That pressure switch simply releases the cruise control.

 

[rebelgregory]

^ What they said. Good looking burb by the way.

 

[aaldape]

Awesome. Thanks guys, that was it. I had never tried messing with the cruise control because I bought this from someone who had just installed a 6.0 LS motor in it, and during a day that I was going through the pinout list at the ECU connector, I don't think the cruise control pin was even attached... Good to know in case I decide to add it though, thanks again guys.

 

[Blue85]

Assuming your LS has a throttle cable (not TBW) and you are using the stock speedometer, the factory cruise control could be reused. But you have to figure out a custom mounting solution for the diaphragm unit.

If it is TBW, you have to use the LS ECM to do cruise control and splice in your control stalk. This requires that the ECM has a valid VSS, but hopefully you have that already. Are you using an electronically controlled transmission?

 

[aaldape]

To be honest I'm not sure about the transmission control, the engine/trans were from an 05 Silverado and so I'd imagine all the corresponding electronic controls went with it.

It is throttle by wire though, but it uses the original speedo cable and gear in the T-case, so no speedo sensor.

I have some schematics I picked up on line regarding the LS swaps that I've used for verifying pinouts and wiring to various connectors/components, so I'm sure with that I could determine what else I needed to get cruise control working in the future.

 

[dyeager535]

Cruise module will be looking for 2000PPM signal, FWIW.

Might be a great time to swap in a stepper motor cruise setup from a later GM. Not sure what year those started, but I've seen them on S10's. Probably not a huge benefit, but you'd eliminate the vacuum line(s).