when braking above 40 miles an hour my car shakes very badly, so ive taken to downshifting. but anyways im pretty sure this would be the calipers. how would i go about checking if the are bad and/or fixing them..o yes she would be an 81 n/a
Most likely you have a warped rotor. But you need to check the calipers too. I don't know if the 81 has a floating caliper or dual piston but either way if something's jammed it's easy to bend the rotor. If you have a run-out gauge you can check it.
Try stopping using the handbrake only, if the problem still exists it is likely that the rears are at fault. Check them as SoM suggested.stamonkey wrote:
> when braking above 40 miles an hour my car shakes very badly,
> so ive taken to downshifting. but anyways im pretty sure this
> would be the calipers. how would i go about checking if the
> are bad and/or fixing them..o yes she would be an 81 n/a
It is also possible that the pad is getting twisted because of excess play. If the pad rattles at low speed (windows down) then this is the case and fixed but adjusting the pad distance. With the caliper off you can take needle nose pliers and unscrew the piston until the proper clearance is achieved. The notches must line up with the peg on the pad.
Enjoy the ride!
But this is a very common problem on Z-Cars. My 82 did this mostly above 60mph and it didn't shake very bad. I rebuilt all four calipers, put on all new pads and had all four rotors turned. The shaking was not as bad, but later I found that one of my wheels had gone out of balance somehow. So once the tire was balanced again the shaking is hardly there at all.
Sloppy bushings in your steering rack and sway bars can cause a tiny bit of shaking at higher speeds also.