Vacuum Hose Entering Firewall

[Marccus]

A vacuum hose exits the manifold of vacuum hoses attached to the firewall and goes to a T - well it looks more complicated than that, maybe a T with a valve.

A hose exits this T and goes to the cruise control solenoid.

Another hose exits the T and goes through the firewall right in front of the driver to the left of the brake master cylinder (you are sitting in the driver's seat).

Where does this hose go to and what it's purpose?

I have a leak in this hose and it may be causing upsetting the vacuum system causing an oscillating and high idle.

Thanks.

 

[rubydist]

MTX car? The vacuum hose goes to the cruise disconnect switch on the clutch pedal, iirc.

ATX car? The vacuum hose goes to the parking brake for the automatic park brake release when you shift into gear.

 

[Racer X]

It goes to the cruise control dump valve on the brake pedal in both ATX and MTX, iirc.

It's a fail safe in case the system doesn't cancel electronically.

 

[Marccus]

Sorry, 1989 MTX w/445K

Thanks.

But is that clutch pedal or brake pedal?

My cruise control doesn't shut off when I hit the brakes.

I am also getting continuous code #67 (either #57 or #67; I'm getting both codes and those are the only two I am getting) - clutch circuit failure.

I don't think I ever did hit the clutch w/ cruise control on, or if I did, I never paid attention if the cruise control disconnected.

So I just have to feed a new vacuum hose through the firewall to the location on the pedal or use a tube splice to remove the part that is leaking.

Do you have to get at it through the wheel well removing the splash guard?

Do you know what size vacuum hose it is?

Thanks a lot!!!

 

[projectSHO89]

It goes to the cruise control dump valve on the brake pedal in both ATX and MTX, iirc.

It's a fail safe in case the system doesn't cancel electronically.

The ATX doesn't use vacuum for any aspect of the speed control. It's all electronic.

 

[Racer X]

The ATX doesn't use vacuum for any aspect of the speed control. It's all electronic.

You're right, I was thinking of the ATX SLO's. My 89 GL had the vacuum speed control servo.