Ok everybody knows the symptoms of warped brake rotors right. Your vehicle hops or vibrates very badly when trying to stop. Well for 3 years now my truck has done exactly that. While going down hill even a little incline is when its absolutly the worst. I have had new slotted brake rotors put on in december of 05 and changed nothing. I have bled brakes, no air in lines. It feels like its coming from the back end. So i had brake drums turned still no change. The only thing i can do to make it brake smoothly is downshifthing and thats what i have been dong for 3 years. Downshifting makes it brake normally. Could it be a bad brake proportioning valve or axle wrap,or worn rear leafs?

 

Well, could it be a driveline vibration or a bad wheel bearing?

 

every now and them we see brand new rotors that are warped maybe have them turned and see if it helps

 

i have read that the wheel bearings could be causing this. only because i have the same excact symptoms.

 

I would be grabbng a dial=indicator and checking the run-out on both the front and rear brakes for starters. I have had more that one set of new rotorsthat where not in spec[warpped]. Sorry to ask this, but the work on the brakes did 'really" get done? I've heard horror storys [rare, but happens] of customers being told/billed for work that never got done. good luck, keep us posted on what you find. 1eye

 

Here is a long shot. I have a vacuum pump from a MR2 hooked up to my after market cruise control. When it is on (powered by the cruise power switch) my brakes will sometimes pulse going down hills with very strong breaking like coming off the highway onto a long downhill ramp. It is almost like anti locks. If I turn off the cruise and thereby turn off the vacuum pump, the pulsing stops. I cant imagine that is your problem but it is an interesting phenomenon either way.

 

I've had this same thing happening for about a year and a half on my '94. Even with new rotors and whel bearings it didn't improve. I need to follow up with what's going on with my rear brakes, but I don't think that they are the cause.

I recently put on some used but new-to-me tires since my old ones were slicks. The new tires seem to have helped alleviate the shaking problems during braking, but they didn't get rid of them completely.