Ill keep this simple. When I brake at moderate to hwy speeds I get a brake shimmy that is felt in the chassis for sure but not so much in the wheel. I had the FR rotors turned 2 years ago but IIRC it didn't eliminate the shimmy then. They may be bad again. I haven't touched the rear brakes or rotors and do not know what condition they are in. I want to know how to tell if it is FR or RR brakes just by driving it (e.g. if the wheel shimmys right along with the shimmy felt everywhere else it is the FR rotors.)

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2001 Bonneville SSEi. 1598xx mi.
great car. Wrecked


Burnt Bonny.

Note if you pull the injectors to obserbe fuel delivery...make sure you leave the plugs in and disconnect the ign. Believe me

Sounds like warped rotors, does the brake pedal pulsate? If yes, I would replace the front rotors with new pads. Make sure you properly torque your lug nuts to help prevent the new ones from warping.

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2004 Bonneville SE 151,xxx- 20% tint all around, 5% tint bar on windshield | 4500k DDM HID low | De-badged | Hardwired Passport 9500ix | FWI(inter-cooler piping) | FE2 Rear Sway Bar | Solid Motor Mount | 180* Stat | Firm Shift Kit



- '92 Bonneville SE - '85 Grand Am - '73 Catalina - '67 Catalina
- '87 Bonneville SE - '82 6000 - '78 Catalina [/color]

OK. thanks. There is no shimmy/pulsing in the brake pedal. Why would a pulsating pedal mean fronts? And I never thought of the loose lug nuts. I'll keep that in mind.

Kris

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2001 Bonneville SSEi. 1598xx mi.
great car. Wrecked


Burnt Bonny.

Note if you pull the injectors to obserbe fuel delivery...make sure you leave the plugs in and disconnect the ign. Believe me

the quality of rotors has declined in recent year, poor quality and corrosion shorten the life of rotors. I no longer turn my rotors and just replace them at every other pad change. Regarding the lug nuts I was referring to even torque all around for even pressue. Sometimes warped rotors can be attributted to incorrect/uneven lug nut torque. The back rotors tend to be less of a problem with warping as they are solid.

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2004 Bonneville SE 151,xxx- 20% tint all around, 5% tint bar on windshield | 4500k DDM HID low | De-badged | Hardwired Passport 9500ix | FWI(inter-cooler piping) | FE2 Rear Sway Bar | Solid Motor Mount | 180* Stat | Firm Shift Kit



- '92 Bonneville SE - '85 Grand Am - '73 Catalina - '67 Catalina
- '87 Bonneville SE - '82 6000 - '78 Catalina [/color]

if you feel the shaking in the steering wheel that topically is front rotors... if you feel it in the seat or floor then you are most likely feeling the rear rotors are warped. the rear park brake is cable driven to the caliper IIRC... Try lightly pressing on he park brake to engage the rear rotors only and see if it shakes.. if it does you found your warp... if it doesnt then you need to look either at the front or some other part of the brake/suspension.

S

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Shane "RedZMonte"
2004 Z16 Z06: Virgin
2000 SSEi: Kenwood DDX512, 3.25" MPS, ZZP DP, PLog, Puck Mount, NGK TR7's, DHP Tuned
1995 Monte Z34: T04e "60" turbo, 42.5# injectors, Borla Catback, OBDII swap, DHP Tuned, Much more...

OK Shane, thanks. I was able to figure out how to that with the ebrake. It's not the rears. So, it's down to front pads, calipers, rotors or maybe the master cylinder. How do I lower the odds?

_________________
2001 Bonneville SSEi. 1598xx mi.
great car. Wrecked


Burnt Bonny.

Note if you pull the injectors to obserbe fuel delivery...make sure you leave the plugs in and disconnect the ign. Believe me

The pedal and wheel have wobble at slow speeds. You can tell, by feel, the the wheels rotate once per wobble using slight break pressure. It's not clear what component this points two.

_________________
2001 Bonneville SSEi. 1598xx mi.
great car. Wrecked


Burnt Bonny.

Note if you pull the injectors to obserbe fuel delivery...make sure you leave the plugs in and disconnect the ign. Believe me

You can eliminate the master cylinder and the caliper right off the bat.
Put new rotors and pads on the front, and Bob's your uncle!

Leon

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2006 GTO
2005 GXP Bonneville (his) (SOLD)
2004 SLE Bonneville (hers)
2004 SLE Bonneville (sons)
2006 GXP Grand Prix (sons)
1998 SLE GMC Sierra
1991 Yamaha FJ1200
1983 Trans Am (SOLD)
1979 Trans Am