Shuddering while braking?

LongrangeLauber · June 5, 2014

Had this problem a while, but now it has gotten worse, a lot worse. As many of yall know I did a whole brake job this time last year where I did a hydroboost swap, put 05+ brakes on the front, SUV dual pistons in the rear, braided brake hoses, slotted and dimpled rotors, EBC green stuff brake pads, etc. Basically everything except hard lines and ABS module. Anyways, when I get down to about 40 mph, the truck starts to shudder a little bit while braking, and once I hit 30 mph and below (while braking), it feels like bolts are coming loose and something is coming out. This is all with regular pressure at the brake pedal. If I apply it harder, it either doesn't shake as bad or doesn't shake at all.

At first I thought it was the tires I had cause I talked to another guy with Dick Cepek FC2's and he said he got the same thing from his truck, but there is no way it is all in the tires. Any ideas on what it could be? THE STEERING WHEEL DOES NOT SHAKE!!!

A couple guesses I have made are:

1) Unbalanced tires

2) bad brake pads/ cracked pads

3) don't think so, but possibly a bad rotor

These are the only things I can think of off the top of my head. Ive replaced just about everything on this truck in the past year (many of yall know lol) so kinda aggravating. Any advice or personal experience with this issue would be greatly appreciated!!

00Silverado4x4 · June 5, 2014

Loose lugs nuts front/rear of truck? That does sound odd. I'd still check for a warped rotor or unbalanced tire as well.

LongrangeLauber · June 5, 2014

Loose lugs nuts front/rear of truck? That does sound odd. I'd still check for a warped rotor or unbalanced tire as well.

Shouldn't be loose my impact does a damn good job on everything else lol. If i have time I will probably rip it apart this afternoon. I'm going to probably take it in to check the balance on the tires. Maybe I threw a weight or something

Sent while cruising down a back road...

Doug_Scott · June 5, 2014

Wheel lugs should be torqued to a specific number. Using an impact gun can actually give you a brake vibration. It will not be tire balance, simply because the wheel assembly will vibrate regardless of brake usage. A vibration from an aggressive tread pattern can happen more during braking. What tire pressures are you running? The tread pattern may create more or less vibration depending on tire pressures. Sorry, I have no recommendation for proper tire pressure in your case.

If the steering wheel does not vibrate or you cannot feel any vibration in the steering wheel, then the front brakes are not likely the cause. Do you feel anything in the brake pedal when the vibration happens?

About all I can think of given the information you supplied is to torque wheel lugs to proper spec, verify that all mounting hardware in the braking system is also torqued to proper spec, and verify that all brake pads are installed with the proper anti-rattle and mounting hardware.

LongrangeLauber · June 5, 2014

Wheel lugs should be torqued to a specific number. Using an impact gun can actually give you a brake vibration. It will not be tire balance, simply because the wheel assembly will vibrate regardless of brake usage. A vibration from an aggressive tread pattern can happen more during braking. What tire pressures are you running? The tread pattern may create more or less vibration depending on tire pressures. Sorry, I have no recommendation for proper tire pressure in your case.

If the steering wheel does not vibrate or you cannot feel any vibration in the steering wheel, then the front brakes are not likely the cause. Do you feel anything in the brake pedal when the vibration happens?

About all I can think of given the information you supplied is to torque wheel lugs to proper spec, verify that all mounting hardware in the braking system is also torqued to proper spec, and verify that all brake pads are installed with the proper anti-rattle and mounting hardware.

Not saying your wrong but all the times I've ever used an impact for wheel lugs I've never had a problem like this. I've pulled these wheels on and off between repairs and tire rotations probably a 100 times and this has been a progressively worsening (I know not a word lol) issue. Just from knowledge and what seems like it makes sense is unbalanced tires but who knows until I spend the money to get them rebalanced. Thanks though

Sent while cruising down a back road...

00Silverado4x4 · June 5, 2014

Forgive me for asking but do you have drum brakes in the rear? If you do, are they adjusted/adjusting properly? I've ran into that problem before, adjusters quit working leaving the shoes not grabbing right in the drum.

LongrangeLauber · June 5, 2014

Forgive me for asking but do you have drum brakes in the rear? If you do, are they adjusted/adjusting properly? I've ran into that problem before, adjusters quit working leaving the shoes not grabbing right in the drum.

No I dont. Stated in OP I installed dual piston SUV rear calipers when I did brake overhaul. I know what you are talking about though. My dad has that problem in his 09 Silvy.

Sent while cruising down a back road...

00Silverado4x4 · June 5, 2014

No I dont. Stated in OP I installed dual piston SUV rear calipers when I did brake overhaul. I know what you are talking about though. My dad has that problem in his 09 Silvy.

Sent while cruising down a back road...

Duh! You did, I'm sorry, bad hair day....& I'm bald....

Are the rotors bolted down before you put the wheel on? I know when my truck was new there was a screw that held the rotors in place prior to installing the wheel. I'm thinking that....highly unlikely...a rotor is torqued a bit from not seating flush prior to the wheel being mounted?

kstruckcountry · June 5, 2014

I really doubt it has anything to do with how your lug nuts are torqued. I doubt it's the balancing too but I guess it can't hurt to check.

I'd be willing to bet it's the EBC pads, mine have recently developed a slight shudder, noticeable to me but I doubt many others would notice. Maybe the pads in the rear?

LongrangeLauber · June 5, 2014

No screws on mine. Were none when it was stock

Sent while cruising down a back road...

LongrangeLauber · June 5, 2014

I really doubt it has anything to do with how your lug nuts are torqued.

I'd be willing to bet it's the EBC pads, mine have recently developed a slight shudder, noticeable to me but I doubt many others would notice. Maybe the pads in the rear?

I'll check fronts first then rears. Not sure why i didnt check these things when I put the new rear in

Sent while cruising down a back road...

kstruckcountry · June 5, 2014

At first I really liked the EBC pads but the mess they make and the vibration they have started has really turned me off.

It could even be warped rotors.

LongrangeLauber · June 5, 2014

At first I really liked the EBC pads but the mess they make and the vibration they have started has really turned me off.

It could even be warped rotors.

Agreed. They had some serious stopping power but they say they are low dust. If that is low dust I wouldn't want to see their other pads with more dust. If the rotors are bad as well (EBC slotted/ dimpled) I will just go with Wagner thermo quiets for pads and regular rotors. I'm beginning to realize aftermarket parts are not all that great. Now wonder they always recommend OEM or equivalent lol

Sent while cruising down a back road...

LongrangeLauber · June 5, 2014

Put new front pads on and it is still doing it. Brake feel is better though now lol

I'm going to ask this guy I know if we can swap wheels and tires for a day to see if it's the tires. If it is tires, I think it's a sign that I need new ones, like 37's

Sent while cruising down a back road...

Doug_Scott · June 6, 2014

Not saying your wrong but all the times I've ever used an impact for wheel lugs I've never had a problem like this. I've pulled these wheels on and off between repairs and tire rotations probably a 100 times and this has been a progressively worsening (I know not a word lol) issue. Just from knowledge and what seems like it makes sense is unbalanced tires but who knows until I spend the money to get them rebalanced. Thanks though

Sent while cruising down a back road...

Its not that you are using an impact gun, it is more that the lugs need to be torqued to an equal value. Ever since manufacturers started downsizing brake components to save weight, rotors have taken a beating. Wheels with un-equal torque on the lugs will create a warped rotor. Same for over torqued lugs.

What most don't get is that the lug nut itself is actually self locking. That tapered tip is not just to help center the wheel on the stud, it also grips the stud as the wheel and the taper connect. No need to run the nuts down at max torque from impact gun. That will create more issues than you have considered. Not trying to argue to put you down, but, in your exposure to that cars that you have owned is not anywhere near the same as the exposure a mechanic has seen. Prior to the late 80's, wheels were rarely torqued, but since then it has completely turned the other way.

The reason rotors and brake drums have screws holding them on was mostly for he assembly line. North American manufactures used to use small spring steel lock washers to hold the drums on. They caused more issues by leaving them on. Cars only came with 2 or 3 per wheel as well.