1966 Coupe DeVille Front Brakes

[njones68]

Re the continuing saga of my '66 front brakes last mentioned in my post in June. After replacing the drums ( New, NAPA's best ) shoes, springs, and a complete overhaul I am still experiencing severe vibration when braking, this gets worse with speed. It is definitely coming from the front brakes (   braking with the emergency only produces no vibration ) and can be felt in the steering wheel. It feels like an out-of-round drum.

Now I'm told by a Machinist friend that nearly all new drums today require turning, especially on the front. Is this the sad state we have arrived at with this Chinese junk everyone is flogging? In all my 50 years of working on cars I cannot remember having these problems with good old American iron. Hard to beleive that parts turned out on CNC machines can be that far out of tolerance, I checked the Manufacturer's web site  ( China ) and everything is ISO certified state of the art but apparently still junk.

Can anyone else confirm my experience?

Thx,   Nigel Jones, Salmon Arm, BC/Can.

[Otto Skorzeny]

Not only with brake shoes but virtually everything else made in China. Rocker arms, pushrods and lifters from China are absolute junk.

Kanter had serious problems with Chinese brake drums several years ago due to incorrect sizes. They had none available for certain models for a long period of time. They were made out of spec and a huge shipment had to be returned. Maybe they ended up being sold to some other supplier instead of being destroyed.

[bill henry]

I would rather find some in a junkyard than put chinese crap on my car. you are risking your life with that stuff!

[Steve W]

I'm with Forrest (Otto) and Bill on this. I would rather have American re-built or wrecking yard stuff on my car than any new stuff from China or Korea or wherever.

There is a sticker on my air cleaner that says "Keep your GM car all GM"..or something to that effect.
I know, with these old cars of ours, that its very hard to do that, but I try to make sure I'm either re-building the original stuff, or replacing it with NOS or decent American used parts unless I just absolutely do not have a choice. (...and even some of the "all GM" stuff is/was suspect!)
Sometimes we don't even really know where the part comes from, what with all the knock-off and counterfit stuff out there, but we have to do the best we can.

But if the "new" brake drums have to be turned and machined anway, then go with a decent set from the wrecking yard.
...just sayin'

["Cadillac Kid" Greg Surfas 15364]

Nigel,
Due to the fact that we have to accept the world as it is, my suggestion to you is pull the front drums and BEFORE you have them turned, be sure who ever pressed them on the hubs for you did it straight and that isn't the problem.  Then have the drums turned.  I don't believe that in the past 20 years I have ever not turned drums before they were installed, especially on the front where the fit to the hubs can off set the center slightly.
Check the shoe  and hardware installation  with the service manual to be sure that is correct, and after adjusting the front wheel bearings as  (again) discussed in the service manual, adjust the brakes.  On my '66 I adjust them a bit tighter than the manual suggests.
Greg

[TJ Hopland]

The iso thing just means you have a documented process that can be checked and therefore you are building what you say you are building.  If your spec was crap you can then test and prove that you are building crap.  I have been told that one of the issues with things like cast drums and rotors is the 'seasoning' process.  Apparently to make something like that correctly the parts have to go through a cooling and heating process before they are machined and to save time and money they rarely do that process so the first time they heat up on the car they change shape.   I know very little about casting and nothing about casting cast iron but it seems very plausible to me. 

["Cadillac Kid" Greg Surfas 15364]

The real issue is the fact that the front brakes vibrate and the rear do not.  The '66 uses the same drums on all four corners, so (without defending the off shore manufacturers) I would look at the installation of the front drums.  Were they pressed on the hubs straight, and if so how far out of round are they with respect to the hub centerline?  I guess that I must be strange, but I always turn new drums regardless of their manufacturer.  Front disc rotors however are different.
If the drums are just within a few thousandths of true, just have them turned and put everything back together.
Greg

[Otto Skorzeny]

How do you know the rear brakes aren't vibrating too? You say you feell the front ones through the steering wheel.

Just pulling the emergency brake isn't going to tell you whether the rears are vibrating because you're unlikely to feel anything through that cable.

["Cadillac Kid" Greg Surfas 15364]

Forrest if they were out of round the car would pulsate enough that it would be noticable.
Greg

[njones68]

Thx to all for the feedback on this topic, will pull the drums next week and check the hubs then if straight will have the drums checked and if necessary turned. The "seasoning" of the cast also makes some sense, must be a reason why all American manufacturers used to toss the engine block casting out in the yard for a while to let them season before boring etc.

Nigel

[TJ Hopland]

With this pressed in hub setup could you install the hub and then turn them so even if things were not perfect they would then be aligned with the spindle? 

["Cadillac Kid" Greg Surfas 15364]

TJ,
If the drums were not pressed on straight, or there was some "debris" under the mating face of the drum it would not be correct.
Typically I have the front drums pressed on and then turned to make sure there are no complications and I have never had a problem (on my '66)
Greg

[TJ Hopland]

Thats what I was thinking, turning them after they are installed on the hub would eliminate minor alignment issues or differences between the drum and the hub. 

[whitewall]

Not sure if this will help but I also went through the same problem when I changed the front drums. Did everything but to cut a long story short for me the problem was the front strutt rubbers were worn. Changed them and the brakes were fine.

Another issue I have is if new brake shoes aren't matched to the drum there is vibration