Car shudders when braking.

[Paul Stubbs]

Slowly working out the bugs on my 67 Fury II.
All drum system. In town brakes work fine no issues. When stopping from higher speeds (40ish) and higher pedal force, the car shudders pretty badly.
I have noticed the parking brake cable is disco'd. Would that in itself cause this phenomenon?

 

[Davea Lux]

You should start by pulling all 4 wheels and inspecting the brakes. The shudder can be caused by brake fluid on the lining, a warped drum or cheap brake linings that are glazed or have the wrong type of material installed. Brake shoes made of the finest Chineseium are famous for squeaking, pulling and thumping as the car is stopped. Another possible cause is worn shocks, worn tie rod ends or worn control arm bushings. A disconnected park brake cable should not cause the shudder but it would be wise to repair this problem.

Dave

 

[Paul Stubbs]

Thanks for your reply! The brakes may have some residual fluid on the shoes, I just replaced the rear wheel cylinders. Cause they were leaking. Shoes looked good as far as material thickness.
Front shocks are probably shot, tie rods don't look great either. Wanted to eliminate the park brake cable as the culprit.

 

[496 polara]

My guess would be warped drums.

 

[Mntac]

I had the same bad shudder problem with the 66 wagon. The brake shoes on it were this brown organic material that around town worked fine but heated up bad when used at high speeds. I swapped them out for the old style metallic brake shoes, looked like crushed metal shavings. No more shudder problem.

 

[Gerald Morris]

Slowly working out the bugs on my 67 Fury II.
All drum system. In town brakes work fine no issues. When stopping from higher speeds (40ish) and higher pedal force, the car shudders pretty badly.
I have noticed the parking brake cable is disco'd. Would that in itself cause this phenomenon?

I would bet on taco salad shell drums. I acquired one recently myself, last Thursday, when the front left quarter of the car dropped onto the drum while rolling. It doesn't give me much pedal-chatter, miraculously enough, but I have discovered some the past couple days as I cruise the newly rebuilt and DECENTLY ALIGNED front end at more nromal speeds. I plan to replace that drum, and likely all shoes this Fall, when the ambient day temperatures drop below human body temp. I prefer to work under such conditions, as while working in high fever environments puts me in a suboptimal mental state.

Pay special attention also to your emergency brakes. Those can get in a SORRY state when allowed to run totally slack, take my Word on it. It's happened to me about 8-9 yrs back, with our family '66 Newport. Still, my first bet would be on the drums. Bad bearings can also cause shimmy-n-shake-brake. Try cruising in the quiet hours and listen to your wheels. That can tell you things.

 

[MoPar~Man]

@Paul Stubbs Did you find the cause of your brake shudder?

I took my '67 Monaco on the highway today, and the little bit of shudder that I was feeling at city driving (30 mph) was really bad at 55 - 60 mph. This is after the entire front end being rebuilt, right down to a new front stub. All new front end parts including the drums. Rear drums have been turned. New tires, all wheels have been balanced, the rears were road-force balanced. New u-joints also. New rear shocks. New rear flex hose - and cleaned out the rear distribution block (found out 2 weeks ago it had junk in it! One port was blocked! Probably from internal disintigration of old rear flex line).

I wonder if the front distribution block can cause this shudder. It has an internal spring - doesn't it? Or the booster? (booster is original, has had no work ever done to it).

I'll have to try the e-brake trick. Might also plug the rear brake line to isolate the front brakes.

 

[Paul Stubbs]

I did see an improvement with new front gas charged shocks. The old ones were horrible.
I need to change the organic brake shoes for semi-metallics. Hoping that helps out.
Sounds like you have gone through most things that could cause a shudder.

 

[Gerald Morris]

@Paul Stubbs Did you find the cause of your brake shudder?

I took my '67 Monaco on the highway today, and the little bit of shudder that I was feeling at city driving (30 mph) was really bad at 55 - 60 mph. This is after the entire front end being rebuilt, right down to a new front stub. All new front end parts including the drums. Rear drums have been turned. New tires, all wheels have been balanced, the rears were road-force balanced. New u-joints also. New rear shocks. New rear flex hose - and cleaned out the rear distribution block (found out 2 weeks ago it had junk in it! One port was blocked! Probably from internal disintigration of old rear flex line).

I wonder if the front distribution block can cause this shudder. It has an internal spring - doesn't it? Or the booster? (booster is original, has had no work ever done to it).

I'll have to try the e-brake trick. Might also plug the rear brake line to isolate the front brakes.

If you slapped brand new drums on up front without having them properly turned for circularity, then do so now. New drums are every bit as subject to distortion as old ones, IF NOT MORE SO! I bought a pair of nice, brand new drums about 5 yrs ago, which were warped out of true by shipment or shoddy QC, and required turning. They've served me very nicely since that. What tiny shimmy my brakes gave a couple weeks ago has since disappeared, so I reckon the weird incident with the wheel popping apart didn't harm that one drum much. I think the fact that the tire cushioned the car coming down saved it. Still, I might yet invest in de-swedging the old drum-hub combo, and having the other drum(s) dressed and ready, if they have enough iron left to warrant it. They're not getting cheaper.

 

[Gerald Morris]

I did see an improvement with new front gas charged shocks. The old ones were horrible.
I need to change the organic brake shoes for semi-metallics. Hoping that helps out.
Sounds like you have gone through most things that could cause a shudder.

The graphite-metal shoes are about as good as modern materials get. I've copped enough of the old mesothelioma shoes to last us the rest of my life here, but I run graphite-metal for the rear ones. I see PLENTY of the 3 inch drums and shoes popping out of the woodwork, including backing plates. I'm tempted, but now have enough stuff to not really need them.

 

[R&R]

No telling. but if I had to put money on one thing. It would be lower control arm bushing. As long as the tie rods, idler, pitman, ball joints aren’t falling apart, wheel bearings not loose. I don’t know if having the fronts adjusted tighter than the back would cause it to shudder, just a thought, on the old semi trucks it does.

 

[MoPar~Man]

I should close this thread by saying that the shudder was being caused by the new front drums. Specifically, they are Winhere (brand) 446541 (2.75 inch x 11 inch) drums. Even though they were new, purchased from a local parts retailer (here in Canada) where I had a look at them for signs of being dropped (dents, etc) they looked fine, they needed to be turned to make them true and round. One more than the other (as I suspected).

Moral of the story- it's probably a good idea to have new drums turned before you install them. They might not take any material off if they're already perfect, so no harm there, and at least you know if there's brake or suspension issues that it's not the drums. I would buy these again, given that there aren't a lot of choices any more for drums. They're about $110 now (about $10 more vs last year), that's about $80 USD. If you have 3 inch front drums, Winhere has P/N 446497 for that.

 

[Just Carbs]

Yep, most new drums suck.
Out of round, inconsistent metallurgy, bad surface texture.
Most all need a good cutting. And often another cut after some good heat cycles.
Minimum cleanup cut on a new or old drum would be .003". Even if it's round.