Low Speed Brake Shudder/High Speed Vibration

[Blue95]

Alright guys I am stumped with my '95 GMC K1500 with 181K on it. I just did all new calipers, SS brake lines, and rotors on the front. pads are pretty new so didn't replace those.

I had a stripped out lower driver side caliper bolt for a while and it was causing a real low speed, like 10 MPH or less, shudder/vibration. Acted just like a warped rotor. Well I am still having this issue. Lower ball joints, idler, and pitman arms are new.

I replaced the wheel bearing on the driver side too, but it wasn't bad to begin with. U joints are new and greased, slight up and down play in the rear by pushing on the shaft, but nothing more than an 1/8". One piece driveshaft

I am wondering if the mounting location for the caliper on the spindle is worn and causing this shudder or if a bad BJ, tie rod end, or bad control arm bushings could cause this? Out of balance tires cause that much problems?

I am also having a vibration when slightly in the gas at hwy speeds, say to get from 70 to 72 to set cruise or I tap the brake to kick out of cruise.

 

[Blue95]

any help guys?

 

[Mean Green]

Long shot, but what kind of pads do you have installed? With new lines and calipers, the pads could come into play. The control arm bushings are also a possibility. When you have the front tires off the ground, is there any play side to side? Up and down? Corner to corner?

 

[Blue95]

Long shot, but what kind of pads do you have installed? With new lines and calipers, the pads could come into play. The control arm bushings are also a possibility. When you have the front tires off the ground, is there any play side to side? Up and down? Corner to corner?

Wagner thermoquiets for pads. Rear drums are all original as far as I know, drums slide right off, but could they be causing the issue at low speed?

Well I told the bushings are looking bad and they do look kinda bad. I am going to check play this weekend when I can get it up on a jack.

I just am so confused, it is like I have a braking or suspension issue and a driveline issue

 

[Mean Green]

Wagner thermoquiets for pads. Rear drums are all original as far as I know, drums slide right off, but could they be causing the issue at low speed?

Well I told the bushings are looking bad and they do look kinda bad. I am going to check play this weekend when I can get it up on a jack.

I just am so confused, it is like I have a braking or suspension issue and a driveline issue

I would start by checking play. Do you feel the vibration more in the steering wheel or the seats/floor? I high doubt that it has anything to do with your rear brakes. Also do you notice any vibration or hum when cornering at high way speeds? Does it pull one direction or another with your hand off the wheel going down the road?

 

[Blue95]

I would start by checking play. Do you feel the vibration more in the steering wheel or the seats/floor? I high doubt that it has anything to do with your rear brakes. Also do you notice any vibration or hum when cornering at high way speeds? Does it pull one direction or another with your hand off the wheel going down the road?

I had the idler and pitman arms done and the lower or upper BJ's recently, dont remember which. I feel it in the seats/floor. NO issue at cornering or pulling.

I think I may have a TC issue at hwy speeds too, but the low speed braking is what is bothering me since the front end brakes is all new.

 

[Hezsus]

Could definately be a wheel out or balance or tires that should have been rotated a while ago.
with the brakes applied at hwy speeds does it vibrate?
does it vibrate with the parking brake on?
Sounds like it could be a bad rotor from factory or mabye there was a piece of something on the hub surface when you put the new rotor on thats throwing it out.
Do you have abs? disable it and see what it does
Put it in neutral and brake, could be a universal, I've had many that dont have any movement until out of the truck. there also cheap insurance
did you check your cv's?

 

[Blue95]

Found my high speed vibration to be a rear u joint cap backing out of the shaft as the morons who did them did not clean the c clip channel and it was backing out, so that is all good now!


Well I am going to have the wheels and tires road force balanced, $9 a wheel at Dobbs. I may also have them take a few thousandths off the new rotors just to be sure, could be out of true.

I do have abs but that isn't the issue.
How can I check for a bad CV? OR what are the bad signs of one?

 

[Hezsus]

I check by prying on them for any noticable play, there will be in and out play so its kinda hard to tell 100%

clunking around corners and bumps, vibrations, similar to wheel bearings and ball joints

 

[sewlow]

I always have new rotors machined before I install them. Some new ones I've bought were out of round so bad right outa the box, it wasn't even worthwhile having them turned.
The RC1concepts on my '98 were damn near perfect, & they have stayed true since day one. They have also lasted much, much longer than any other replacements that I had on it.
The exhuberant backroad driving & canyon carving that I just love to do can beat up front rotors pretty good. The stock style rotors can't take the heat of that without warping.
The RC1's can.