Cruise Control vacuum controller test
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More Turbo
Joined: Jun 2003
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Cruise Control vacuum controller test
1990 f250 zf 5-speed. Is there a way to test whether the vacuum controller for the cruise control is functioning properly? I'm talking about the unit mounted near the firewall on the driver side fender. Maybe applying vacuum to the various ports to test it? Symptom is erratic speed control. All vacuum lines look tight.
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Joined: Feb 2005
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From: Finleyville, PA
Have you replaced the brake switch (it might be the one that was recalled) on your master cylinder? I was having problems with my cruise control, and then noticed that my brake lights wouldn't stay on. If I only pressed the brake enough to light the brake lights and then held it, they brake lights would go off. I can't remember if the problem ended up being the brake pressure switch on the master cylinder, or if it was the brake booster, but it definitely wasn't the brake light switch on the pedal.
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I had a look at the master and there is a three wire connector coming off the side. Those connections look good. If I look down into the reservoir itself, there is a float that rides up and down little guides that I suppose is part of the switch? If I push on it a little bit it will float back up. If I push it down as far as it goes it will stay. If I then push on the brake pedal it floats back up. Does this make any sense?
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Joined: Feb 2005
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From: Finleyville, PA
The switch I had problems with threads into the master cylinder, but I'm pretty sure it is the switch they replaced in the big recall. I think my main problem was a leaking brake booster, which allowed the pressure to bleed off, causing problems for both my brake lights and the cruise control.
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Chris-
Is the servo the vacuum unit I described? Did you replace it with a used one or a new one?
Steve
Is the servo the vacuum unit I described? Did you replace it with a used one or a new one?
Steve
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Chris-
Yes, that is the part i'm talking about. I guess it's either that or the speed sensor where ever that is. Before I spend $$ on a new servo, I was hoping there would be a way to test it though.
Yes, that is the part i'm talking about. I guess it's either that or the speed sensor where ever that is. Before I spend $$ on a new servo, I was hoping there would be a way to test it though.