Brake problem.

[Hightower79]

67 with Drum brakes all around (no servo).

After a long time off the road I took my truck for test drive. I was happy with all the work I had done, however I have a brake problem.

When lightly applying the brakes the truck pulls to the right and there is little brake effort (certainly less than expected). If I keep applying foot pressure to the brakes (Braking harder) there is little more brake effort until the LH wheel locks up.

Before I strip things apart am I likely looking at a RH or a LH brake issue?

Also, can someone tell me if the rear (firewall) master cylinder bowl goes to the fronts, as this was a lower level than expected.