Dig

Hey all,
Just a question regarding braking, when I'm going a decent clip and coming to a stop, the truck hops pretty good - more so when I'm braking quicker, any ideas what this could be? Front or rear brakes? Warped rotor, etc. I have no way of lifting the truck right now so it will more than likely need to go to a shop.

Thanks again,
Dig

Mexstan

Possibly the result of worn out rear shocks.
Once you resolve the problem, let us know what fixed it so that we can all learn.

Rug_Trucker

Probably the rear. These things are heavy on the nose, and the weight goes forward when you brake. Does your truck have the ABS? More info is needed. How's the rear tires?

Dig

Truck does have ABS and the rear tires look like they're in decent shape, probably best just to have a shop look at it. There's a system on the driver side inside of the frame near the rear axle (The RWAL?) that's already been bypassed it looks like.

Rug_Trucker

IIRC li looks like a drum brake wheel cylinder on the axle. It's rebuildable. They are sometimes sold for $275+ if you can find them. Probably just a couple of 0-rings.

cougar

If you are going to tear your rear brakes apart, upgrade. 3" shoes and larger brake cylinders. Both my 91.5 and 92 had something I called basketball bounce. It occurred while coming to a sow stop. Never did fully figure it out but I suspected either spring wrap and/or out of phase drive shaft. It went away on my 92 after having the drive shaft shortened.

Dig

I did just replace the u-joints in the rear shaft and I have the front one out right now looking for a new one. I don't know if that could possibly be a reason for the hopping/bouncing.

pind

How about rear drums gone out of round?

Mexstan

Hmmm, not saying that you are wrong, but wouldn't this create a brake pedal pulsation before any bounce. The OP has not mentioned any pulsing.

Dig

My bad, pedal feels all normal, I'm just feeling and seeing the truck hop/bounce.

cougar

Search YouTube for something called drive shaft phasing. Out of phase U joints and or out of spec pinion angles will do it.

Dig

Hey all, just came back to wrap up the issue, I had my guy take it for a drive and he opened up the breaks and adjusted the front brakes (one had a sticking caliper). I got the truck back and the hopping has gone away. Seems odd but that's what seemed to do it, just figure I would let everyone know.

Dig

Rug_Trucker

thanks!!

KRB

Cool video. I always knew angle and phase had an effect. To see what it actually does really helps.