Help with my braking problem

[BlueOx]

I’m trying to diagnose my braking problems and thought I would post here. I have a K5 with D60/14blt. The front calipers have been ground down to fit 15” wheels. I rebuilt the calipers about a week ago. When I hit the brakes the truck pulls real hard to the right. Also when I hit the brakes I hear an air sound from the brake pedal area. It sounds like I’m pushing on an air bag. I thought it is the brake booster but the brake pedal is not hard, it’s soft. I bled the brakes but it still does it. Could the front calipers be the problem since they are ground down? Any ideas would be great.

Thanks.

 

[pauly383]

[ QUOTE ]
I thought it is the brake booster but the brake pedal is not hard, it’s soft

[/ QUOTE ]

It could still go bad like that . My first one and the parts store replacement both went real soft , pedal did really nothing . Luckily I was in a driveway both times . New booster fixed the pedal . As for pulling make sure all the parts the caliper slides on are smooth with a little disc brake ( hi temp ) grease on them ( none on pads ) /forums/images/graemlins/k5.gif

 

[BlueOx]

Is there a way to test the brake booster? I would hate to buy one and that not be the problem.

 

[pauly383]

If it helps , when they go bad like this your engine will change idle speed , maybe stall too , since its vacuum operated . Also unlike with a good booster which makes stiff pedal with engine off , bad booster could make pedal not really work at all if bad /forums/images/graemlins/k5.gif

 

[diesel4me]

You can do a crude test to check the diaphram with one of those Mightyvac tools they use to test vacuum advance and other vacuum operated devices--you will need to find something that will fit in the vacuum hose hole that will allow the mightyvac's hose to connect to it,pump it up,and watch the gauge to see if the diaphram has any leaks--you wont know if the rest of the booster is good until you install it unforunately.Usually when a diaphram fails,you can hear it hissing,either inside the cab,or at the master cylinder,there is a hole at the bottom rear of the master,
sometimes you can hear it leaking there--thats what mine did. /forums/images/graemlins/crazy.gif