Thanks, I was afraid it is a clutch issue.  Appreciate you thoughts.

If the right side clutch was not driving at all, then when you released the left side the dozer should not have moved at all. I think there is something wrong with the controls on the left side clutch.You should not be getting feed back like that through the pedal.

You would also know if one side wasn't driving as you would not be able to keep the machine driving straight.

have you driven it forward and back any real distance say a 50 yards or so if one drive isnt working correctly it should wander to that side if driving evenly it should stay straight on flat country

The movement in the brake pedal you described is caused by failure of the bevel gear bearings (cross shaft) that I suggested you check in my first reply. Care must be taken in setting the clearance of these bearings to prevent premature failure of the new bearings. Your problems require removing the steering clutches to replace the Teflon seals.
Craig

If the brake was getting feedback from worn bearings wouldn't it be more likely to be the output shaft to the final that has the worn bearings? The brake drum is mounted to that shaft not the bevel gear..The procedure for setting up the bearings is not just to prevent bearing failure, it is also to provide the correct contact pattern between the bevel gears to prevent premature wear.
The more I think about this the more I think the problem is in the left side clutch not releasing rather than a side not driving or braking. Either way I would not drive it anymore than necessary (ie to load it on and off a truck).

Thanks, I guess it's time to put it into the shop.

I had to replace the Teflon rings(seals) on a D6C and 2 D6Ds(same steering clutches) because the steering clutches would not release. These tractors all required the bevel gear bearings to be replaced. The D6C bevel gear bearings were so far gone that the steering clutches would move enough to cause the same "jump back" in the steering brake pedals. The output bearings were also worn out this is a major repair.
Craig

Thanks, would you have an estimate for what I can expect to pay to get it fixed?  I've been told the clutches could be $4-5 each at Cat.

John

That's $4-5K!

The steering clutches are probably okay, just needing seal rings. Your major expense is going to be labor. The cross shaft bearings being shot is the big expense in labor. I used to do my own mechanic work but I'm now disabled. I am fortunate to have a independent mechanic that I trust and I get my parts from Florin Tractor Inc. Caterpillar dealers are great, they stand behind their work but they charge a premium.
Craig