Consulting the list for wisdom..
1970 Ford Torino
Was driving around Lake Tahoe, using the brakes alot, due to curves, hills,
and congested traffic.
Strange vibration that is speed sensitive and intermittent. Comes on
gradually, and builds in intensity. Similar feeling to driving over
centerline dots with both sides of the car. Applying the brakes once this
vibration has begun intensifies the vibration. The entire car is shaking.
Vibration doesn't change if only the parking brake is applied, nor does it
change in neutral and coasting, or coasting and engine shut off. Vibration
disappears at speeds below 20 mph. There is no pulsing of the brake pedal at
slow speeds, and the brakes feel normal before the vibration sets in. Pulling
to the side of the road and letting things cool makes it go away.
I was worried I had a wheel falling off, it was that strong of a vibration.
Pulled into Les Schwab in Carson City, put it on their rack. Wheel bearings
feel fine, wheels balanced out fine, no tire separation found, all suspension
parts are fine except some play in idler arm and pitman arm. Rear brakes are
fine, front rotors don't show excess heat or glazing, and mic'd out just
slightly under spec, as I knew they would (last brake job turned them just
under). Front and rear u-joints are fine. Brake booster, master cylinder,
and proportioning valve are one year old and have under 1000 miles on them.
Left scratching my head, no problem found.
Car ran and drove fine at all speeds from Carson City to Reno. After some
bumper to bumper traffic in Reno, but not immediately after, the vibration set
in again. When I say vibration, I mean, like the car might explode. Pulled
off at Boomtown, tried to call a friend to come rescue us, but got his voice
mail. Decided to try to limp along at slow speed, and again, everything was
fine. Made it to just outside of Nevada City, and it came back again. Pulled
over in Grass Valley, cooled off, made it the rest of the way back to Chico.
Everytime I pull over I expect to find a red hot rotor, or a wheel falling
off, but there is no excess heat coming off any of the wheels. There is more
brake dust than normal, and I am guessing it is related to the front brakes
some way, but what?
David Riker
davriker@digitalpath.net
http://community.webshots.com/user/fool4mg
http://www.myspace.com/fool4mg
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