88 Reatta cruise release switch

[johnwilly]

I need a little clarification on the function of the cruise release switch. 
I disconnected the vacuum line that goes to the release switch and applied vacuum and there was a very small leak. I then depressed the brake pedal and the leak virtually went away. This seems opposite of what I thought it should work. 

The cruise seems to work fine. 
thanks. 
 

[Jolly_John]

You'll have better luck getting an answer, if you post on the specific Reatta forum found in the BUICK portion here on the AACA board. Here's a link to the Reatta forum. John

 

https://forums.aaca.org/forum/11-buick-reatta/

Edited November 16, 2022 by Jolly_John (see edit history)

[joe_padavano]

It's the same cruise release switch used on every GM of that vintage. It is a normally closed vacuum switch that is supposed to open when the brake pedal is depressed to vent all vacuum in the system and instantaneously release the cruise servo. If the switch is not venting properly when the pedal is depressed, the cruise will work just fine under normal conditions, however it may not release fast enough in a panic braking situation. That is the sole purpose of that vacuum switch. Normally, the electrical contacts in the switch will also release the cruise servo, but it might not bleed off vacuum and disengage the throttle as fast as it could in a panic situation.

 

[johnwilly]

Appreciate the feedback. What you are saying makes sense, I’ll do some more investigation.

Thanks!