Shuddering when braking

[dtbnz]

Hi, I have had a what I would describe as shuddering when braking (mostly down hill). Have had the rear brake drums skimmed incase they were out of round, new steering stabilizer, new front leaf spring bushes all round, new front antiroll bar bushes. Felt like it had gone away, but drove it yesterday and was bad coming down a long straight hill, front was bobbing up and down slightly with cab shuddering. Truck is a 1982 K10 Silverado. Have Falken 33x12.5-15r tyres with really good tread on front. Only thing I have not done is rear leaf spring bushes. Any suggestions on what it might be and how to fix?

 

[squaredeal91]

Sounds like Front brake rotors possibly.

 

[PrairieDrifter]

Warped rotors.

 

[Rusty Nail]

Turn the front rotors.

 

[Ricko1966]

Do you feel it in the steering wheel?

 

[dtbnz]

Do not feel it in steering wheel. Think I might jack up front take wheels off and put a DTI on the rotors to see if they are warped. But everyone I spoke to kept saying it’s the rear drums that is causing it, so will be good to check the front hubs. Will keep you informed on outcome

 

[squaredeal91]

Sounds like rotors and probably is. But here comes another one of my stories lol. Last year I felt that warped rotor feeling on our 99k1500 suburban. But It was coming from the right rear. I removed drum and found a spring. It wasn't broken and I put it back on and fixed it. Was strange to me how much it affected everything.
And ill add now that I'm remembering more. Another one of my symptoms was I felt the pulse feeling in my brake pedal with that spring out. And I don't have hydroboost in this burb.

 

[PrairieDrifter]

You don't always feel front rotors in the steering wheel. At least not in all decel situations.

 

[Rusty Nail]

Meh.

 

[bluex]

Gently apply the emergency brake while holding the release handle. If you feel the same vibrations it's from the rear. If you don't it's in the front.

 

[dtbnz]

Put a dial indicator on the rotor and when rotating it was 004” or 0.100mm out both side. Would this be enough to cause the shudder? Got access to a lathe if I have to skim them. But don’t want to take them off if the runout is acceptable.

 

[Ricko1966]

Okay I just went and read your original post I don't think the problem is rotors,82K is hub and hat I believe, yes yours are out of spec but only if you had the rotors torqued evenly and made sure there was no dirt/rust in between the hub and the rotor. Dress the hubs and the rotors torque the rotors and check again.but the cab bobbing up and down .004 runout on a rotor not the cause. Imho.

 

[Steppin Razor]

I have a similar problem, and I suspect it's not the brakes at all, since my rotors are only a couple of years old, new front pads, and I rebuilt my drum brakes for this problem and still have it. At first I suspected the praking brake, but it seems to be working fine pre- and post- rebuild. My thought is something suspension related, maybe U joint, or bushings. Hope it's not a bent axle, but we have some African bush level road quality here.

FTR, mine is a shudder that feels like it's coming from the rear and feels almost like pulsing brakes. Maybe I got one of those rare super slow drum ABS brakes

 

[dtbnz]

I noticed one of the inner brake pads is nearly down to the metal, so gonna order a set, then pull caliper and disc off and will dress it with flat dresser. My manual says should be no greater than 006” out. So will check all that when they out.

 

[Ricko1966]

I noticed one of the inner brake pads is nearly down to the metal, so gonna order a set, then pull caliper and disc off and will dress it with flat dresser. My manual says should be no greater than 006” out. So will check all that when they out.

Sounds like you have a caliper,a hose,or a slide problem