1/2 ton vs 3/4 ton MC????

[Kapdin]

Soooo it has come to my attention that they are diff, which makes sence but really did not dawn on me. So went and picked a 3/4 ton up and installed it but noticed the lines are opposit. On the 1/2 ton the bigger diameter line was in the back of the MC and smaller in front.. while now on the 3/4 ton its the opposit. Any reason? i just swapped them and bled them.

 

[bucket]

People have done what you did and it has worked just fine for them. I personally would swap the fittings and re-flair the lines.

 

[Kapdin]

so even tho the lines them selves are diff size just change the fittings?

 

[bucket]

so even tho the lines them selves are diff size just change the fittings?

They are? Hmm, I'm going to look into this when I head outside in the morning. I thought the rear line was 1/4 inch on all of them.

 

[Kapdin]

yea, i also checked my k30 and they also are diff. And when i swapped rear axle's on the 79 i had to add and addapter to the break line cus the wheel cylinders were bigger than the 1/2ton.

 

[89Suburban]

 

[bucket]

Looks like you did it right and I learned something today. I had thought that ALL dual reservoir master cylinders had the front brakes operating off the rear cavity, apparently that's only true in recent years. Everything I have with an aluminum cylinder has the rear brakes (1/4 inch line) operating off the front cavity, while everything I have with a cast iron cylinder has the rear brakes off the rear cavity (even my '70 Impala), EXCEPT for my '79 K30 with hydroboost. It is set up like the newer aluminum cylinders. At any rate, all the trucks have the 1/4 inch (rear) line going to the same spot on the prop valve.

 

[Kapdin]

lol, ya i had time to call an old buddy that knows these alot and he assured me thats right, the larger resivore is always for the front becuase of the disk brake while the smaller res. is for the rear drums. Also drove it today and wow works great.