I've got a 99 Tacoma TRD...My problem is that, when I apply the brakes on a wet surface the brakes lockup and the truck slides..no control I've got oversized tires on,i was wondering if this might be a problem

I also get a vibration on the freeway over 50 mph

Thanks

Does this happen only on wet surfaces or on dry as well?

I kinda have the same problem with the rear brakes not working. Someone mentioned that junction block to me before. Sounds like yours is clogged or something. Maybe that's whats wrong with mine as well. When I last tried bleeding them I was able to get the rears to finally start working while on jack stands, but once I started driving it again I lost the stiffness in the peddle??? I would imagine the rears aren't working again. Fred