57 Tbird power assisted brakes.

[Critterpainer]

Any sign of damage on any steel line? Slightly pinched from a poorly placed chain at some time or a stone strike? Other than the primary/secondary shoes flipped I don't know where else to look!

This page contains affiliate links for which I may be compensated. As an eBay Partner, and Amazon Associate I may be compensated if you make a purchase at no cost to you.

 

[Pink T-Bird]

Any sign of damage on any steel line? Slightly pinched from a poorly placed chain at some time or a stone strike? Other than the primary/secondary shoes flipped I don't know where else to look!

For anyone interested in an update to this saga.... I put the car away for the winter until last week.

• No damage visible on any of the steel lines.
• I'm not sure what I did, or when I did it, but all 4 wheels now lock up when doing a panic stop (on a closed course) from 20 mph. But still pulls to the right in proportion to brake effort (planned stop for a light/stop sign barely noticeable, hard stop pulls hard to the right).
• After trying a number of other things without success, in exasperation I switched the front tires and drums left to right. I also swapped the outer wheel bearing left to right so it stayed with its drum. I cleaned the shoes and drums thoroughly (again) with brake-kleen when swapping sides. The car then pulled to the left! Progress? (NOTE: mechanic claimed he moved drums side to side last Fall, so why does it make a difference when I do it?)
• I left the drums switched, but put the tires back in the original locations. Car still pulled to left. AHA! I finally know it is the drums or the new wheel bearings. BUT WHY?!?
• Pulled the bearings and drums for close examination. No obvious problem. Took the drums to the local machine shop to be turned and measured for any difference in run-out, ID, or any other dimension or tolerance. The machinist clearly thought I'm nuts when I explained my issue, but he will check the drums over anyway. Waiting to pick them up.

 

[Critterpainer]

Geeze A dual master drum/disc conversion would have been easier and cheaper. I'm beginning to think defective drum/bearing hub assembly? Perhaps distorting when a wheel bolts to the drum?

 

[Ward 57]

I'm a bit of a loss. The problem moved with the parts. If you left the shoes in place and the problem moved then you did a good job of narrowing it down. Maybe try buying new drums $300 to make sure they are a matched pair. There is something weird about that drum.

 

[Pink T-Bird]

Geeze A dual master drum/disc conversion would have been easier and cheaper. I'm beginning to think defective drum/bearing hub assembly? Perhaps distorting when a wheel bolts to the drum?

We have a Winner!
The shop said the drum that had been on the side that pulled wobbled "all over the place" when put on the lathe. They suggest the drum was deformed at some point in the past either by someone trying to press the hub out without cutting the swages, or resting the car on the drum without the wheel on. They said hubs rarely get deformed to the degree they saw, but did not isolate hub vs. drum. Other drum/hub was true. Both had plenty of material left to turn down further, but it's pointless for the wobbly one. I asked them about replacing the drums as a pair and they said no need, just the one. So I guess this pull was there from the time I bought the car last year and never noticed it until to my first panic stop.
Just to be thorough - since I did replace the wheel bearings/races and CASCO now sources them from China, I reinstalled the old USA made races in the wobbly drum. I've had 'hit or miss' experience with Chinese car parts, mostly "miss". The pull was still there, so not mis-machined bearing races causing the wobble.
I get a perverse joy, I guess, out of keeping the old engineering technology in working order which is why I did not consider a disc setup on a car that has been kept at factory specs all these years.

 

[Critterpainer]

Wow!!!! What a weird issue to have!... I had a similar issue 30 years ago when I lost a front wheel off my 4x4 at 70 MPH (never could read a speedometer well). I put the spare on and stole 3 lugnuts off other wheels to finish the trip, but brakes were never the same.

 

[Ward 57]

I'd replace both at the same time. You don't want one turned to the absolute minimum and the other with still a lot of meat on it and then end up with one that is still wonky. Same principal of replacing tires in pairs or in the case of all wheel drive vehicles all four at the same time. Tell me it isn't so, I bought a hub and bearings from CASCO a couple of years ago and they were made in the USA. A tire shop had their lug guns turned up too high and spun a lug.