Air Squeak on 70 series when braking

[Eric Winkworth]

Hey guys
I have a 1986 BJ70 and I get and squeak when the brake pedal is at a certain level of depression, sounds like the booster is letting pressure out into the cab and gives off a fairly loud squeal... Is this a sign of a bad booster? Braking performance hasn't been effected that I notice.

Any comments/direction would be appreciated!

Thanks
Eric

 

[jblueridge]

I guess your brake warning light does not come on...
Does your brake warning light function correctly? There is a vacuum sensor/switch that registers not enough vacuum and turns the light on.
Since I installed a larger 2 diaphragm booster, my warning light comes on fairly frequently.

 

[Eric Winkworth]

just today I started getting my idiot lights popping up... typically I would have to rev the engine about 2000 rpm to get the idiot lights to turn off on a cold start up, is that that vac sensor? Now it seems like it cycles on off, on off quite a lot... hot hot weather seems to make it worse... its the e brake light and the battery light beside it, I always figured it was a chargin relay or something

 

[jblueridge]

The brake light in the dash is wired to the e brake handle as well as the vacuum sensor/switch. I think it is also connected to the brake master cylinder.
Any of these can make the light come on.

 

[Eric Winkworth]

what about the battery light that's the one comming on with the brake idiot light