M1009 Help needed

[maritimer]

so somethings pooched in my brakes........
well the other night i was out with a lady friend and after i left her place i was heading down a country highway at about 3am doing 60-65mph* i was in a good mood so dont hassle me about the speed * there was a bit of snow on the roads and as i tap the brakes to negotiate a turn my tail spun up to meet me. turns out my front brakes arnt active.

whats the cheapest/easiest way to tell if its the master bypassing or the front calipers seized? keep in mind that i really dont want to have to redo the brake syustem more then once as DOT 5 here is $16 for 200ml.

known symptoms. pedal drops to about an inch to an inch and a half from the floor before grabbing. onyl grabs the rear brakes. and then only faintly unless on slick roads where it locks the rear end up.
i am thinking its the master, but if you pros know of anything else to check please let me know. also whats the correct NAPA part number for the M1009 master cylinder

now my lady friend likes my truck so i realy really need to get this beast back up cause as she puts it " something about these big ol diesels get her motor fired up"

Thanks a bunch guys

 

[FMJ]

Usually the seals in the Master, check the fluid levels in the reservoirs, if they are good, its most likey the Master cylinder. Can you pump them up at all?

 

[maritimer]

if by pump them up you mean when they bottom out on the first pedel and i let off a split second and reapply they get a tad firmmer then yes sortta

 

[CCATLETT1984]

sounds like either bad seals in the master, or you have air in it.

you may have to bench bleed it.

 

[maritimer]

i figured that it was likely the master. i may as well pull it and put a new one on, save this one for a rebuild later on. anyone know the correct NAPA part number? they have 2 listed for the 85 blazer with a 6.2

 

[CCATLETT1984]

I'm sure someone with a m1009 will chime in, as the trucks are different so i dont know.