Another braking question

[mocrawler]

I have an 89 1/2 ton suburban.The brakes have all but quit working so I removed the wheels and checked the pads . They are all fine. I then tried to bleed the lines thinking maybe they had air in them. Even when I pump on the pedal no fluid comes out of the lines. And yes the master cylinder is full of fluid. I am going to replace the master cylinder tomorrow. Do you think i'm on the right track?

 

[kd7kmp]

I have an 89 1/2 ton suburban.The brakes have all but quit working so I removed the wheels and checked the pads . They are all fine. I then tried to bleed the lines thinking maybe they had air in them. Even when I pump on the pedal no fluid comes out of the lines. And yes the master cylinder is full of fluid. I am going to replace the master cylinder tomorrow. Do you think i'm on the right track?

You could be, but it's had to say. If there are no obvious leaks, then there is an internal problem. It could be the MC or it could be frozen calipers, or bad hoses, etc.

I assume you know the proper way to bleed the brakes...right? If so, I'd start with the MC. It is a relatively inexpensive part to replace, just kind of a pain in the butt.

Kevin

 

[mocrawler]

Yep, i've checked all four brakes. I'll change the MC tomorrow and go from there.

 

[4X4HIGH]

The bleeder screws do become clogged with crap so i would either replace the bleeders screws or remove them and clean them out (a drill bit of the proper size works for this) so you can attempt to bleed the system first.

 

[mocrawler]

I swapped the master cylinder and nothing changed I loosened the lines at the brakes and it flows fine. I think all of the calipers are plugged. I know they've never been changed. I guess its about time.

 

[Muddytazz]

Couple bucks for bleeder screws will save time in having to replace the calipers if not needed.

 

[mocrawler]

I pulled the bleeder screws and cleaned the holes in them. I even stuck a small piece of wire into the caliper itself and still go nothing. Is it possible there could be rust in the system?

 

[Muddytazz]

Pull the inlet hoses off your calipers, if you are getting fluid out of the lines, then the calipers are bad.

 

[mocrawler]

I did it. Lots of fluid coming out. I am going to pick up calipers tomorrow.