master cylinder toast???

[General Mayhem]

hey guys i just bought a 1988 full size Jimmy and i love this thing but the brakes suck and it is starting to make me mad cause i have been changing parts and bleeding them like mad,

now this is what it is doing the pedel goes right to the floor boards and it seems to have no presure to me this is a master cylinder, but i want to be sure before i change it,

And when i get my buddy to push the brakes i notice fuild goes flying up in the first section of the reservoir (closest to the fire wall) now to me that means that there is a check vavle or something that is toast and it is getting blow by,
can any one verify this before i go spend more money?

thanks Tom

 

[Thunder]

Looks to me like the MC is bad. I would get a new one.

 

[Mudstud]

It could be a bad MC but the fluid squirting out is normal. Have there been any mods doen to the brake system? 14 bolt swapped in, 4 wheel disc, anything like that?

 

[General Mayhem]

It could be a bad MC but the fluid squirting out is normal. Have there been any mods doen to the brake system? 14 bolt swapped in, 4 wheel disc, anything like that?

no this is a dead stock truck with a 72000 miles

 

[Mudstud]

I'd check all component for leaks- wheel cylinders in the rear, T fittings, caliper connections. If you have no fluid displacement in the front reservoir when the top is off and the brakes are applied then yes I wouold say the MC is shot. When you replace it be sure to bench bleed it before you put it on the truck.