High idle, goes higher when brake is pushed

[Jason Warrum]

It looks like the PCV connection. The brake booster connection comes from the front of manifold through a preformed steel line that transitions to a rubber line at the booster elbow.

Exactly

 

[Jason Warrum]

Found that with the water trick or just by checking with eyes? Is that a feed for the brake booster or what?

Took off air cleaner and looked. Same thing happened in my 94 c1500 I haven’t touched the booster yet. Gna swap this first. Will update tmorow after work

 

[GoToGuy]

A booster check. Before starting step on brake pedal and hold while cranking and start. What does brake pedal do?
1. Nothing. 2. Pulls lower to floor.

 

[Jason Warrum]

Found that with the water trick or just by checking with eyes? Is that a feed for the brake booster or what?

Took off air cleaner and looked. Same thing happened in my 94 c1500 I haven’t touched the booster yet. Gna swap this first

A booster check. Before starting step on brake pedal and hold while cranking and start. What does brake pedal do?
1. Nothing. 2. Pulls lower to floor.

pulls to the floor.

 

[Jason Warrum]

A booster check. Before starting step on brake pedal and hold while cranking and start. What does brake pedal do?
1. Nothing. 2. Pulls lower to floor.

Pulls to the floor. But it doesn’t seem to idle as high for and not as long when I do that and start it. But I did pull the vacuum line off the booster and try to plug it with my thumb and that didn’t seem to change much.

 

[scott2093]

Scanner may be useful. Have you tried seeing if there are any codes?
TPS reading right?

 

[Jason Warrum]

Scanner may be useful. Have you tried seeing if there are any codes?
TPS reading right?

No I haven’t. But no fault lights are on the dash so never even thought about that. I also thought about changing tps, but would the brake being pushed have any type of affect on the tps? Again I’m a tinkerer not a mechanic

 

[GoToGuy]

If nothing happened it meant there is a vacuum problem or booster failure. The fact that it had vacuum and pedal reacted. Have you checked all the vacuum lines, just to be sure. They look fine but get loose on the ends from age and heat. I second it being a good idea to hook up a scanner and check for normal sensor operation.

 

[GoToGuy]

It was just a quick brake booster check, not throttle or TPS function , cause you mentioned brakes and booster .