1985 Cruise Control Issue
Thread Starter
Instructor
Joined: Apr 2022
Posts: 181
Likes: 118
From: Oregon
1985 Cruise Control Issue
About a week ago I had a strange issue with my cruise control. Got on the highway and set the cruise at 65. The car slowed to about 60, then accelerated to almost 70. Tapped the brake to shut it off, then tried again. It did the same thing again, so I just urned the cruise off and finished my journey. On the way home I tried it again and the cruise would not engage at all. Testing it on a drive again today it still did not work.
I have traced all of the vacuum lines and cannot find any issues. Tried pulling up on the clutch and brake pedals together while setting it - no luck. Tested the vacuum check valve and it seems to work normally (ordered a replacement anyway). HVAC controls all seem to work normally. I also pulled both lines off of the servo, and tried plugging them with my fingers. It will not hold a vacuum with either or both ports plugged. It makes a hissing sound while trying this test bit I cannot feel where any air is escaping.
My current guess is that I need a new servo. Anyone else have this experience? The way it acted up initially makes me think it is vacuum related.
Thanks!
I have traced all of the vacuum lines and cannot find any issues. Tried pulling up on the clutch and brake pedals together while setting it - no luck. Tested the vacuum check valve and it seems to work normally (ordered a replacement anyway). HVAC controls all seem to work normally. I also pulled both lines off of the servo, and tried plugging them with my fingers. It will not hold a vacuum with either or both ports plugged. It makes a hissing sound while trying this test bit I cannot feel where any air is escaping.
My current guess is that I need a new servo. Anyone else have this experience? The way it acted up initially makes me think it is vacuum related.
Thanks!
Safety Car
Joined: Aug 2009
Posts: 3,751
Likes: 276
From: Melbourne, Victoria, Australia
About a week ago I had a strange issue with my cruise control. Got on the highway and set the cruise at 65. The car slowed to about 60, then accelerated to almost 70. Tapped the brake to shut it off, then tried again. It did the same thing again, so I just urned the cruise off and finished my journey. On the way home I tried it again and the cruise would not engage at all. Testing it on a drive again today it still did not work.
I have traced all of the vacuum lines and cannot find any issues. Tried pulling up on the clutch and brake pedals together while setting it - no luck. Tested the vacuum check valve and it seems to work normally (ordered a replacement anyway). HVAC controls all seem to work normally. I also pulled both lines off of the servo, and tried plugging them with my fingers. It will not hold a vacuum with either or both ports plugged. It makes a hissing sound while trying this test bit I cannot feel where any air is escaping.
My current guess is that I need a new servo. Anyone else have this experience? The way it acted up initially makes me think it is vacuum related.
Thanks!
I have traced all of the vacuum lines and cannot find any issues. Tried pulling up on the clutch and brake pedals together while setting it - no luck. Tested the vacuum check valve and it seems to work normally (ordered a replacement anyway). HVAC controls all seem to work normally. I also pulled both lines off of the servo, and tried plugging them with my fingers. It will not hold a vacuum with either or both ports plugged. It makes a hissing sound while trying this test bit I cannot feel where any air is escaping.
My current guess is that I need a new servo. Anyone else have this experience? The way it acted up initially makes me think it is vacuum related.
Thanks!
