Front end mystry

[apbright]

I have had some have problems with my front end recently.

A month ago the front-right brake would 'bang,' that is when applying the brakes with moderate pressure, a very loud bang could be heard, and also felt a strong hit in the brake pedal. I tightened up the brake wedge, and the problem seemed to go away.

Now one month later, back from tour, I was shocked to find the front-right part of the wishbone broken - as if the top of the spring perch had rotated forward through it (see picture). It was clear that the break had happened some time ago, as there was at least mild rust visible on the fracture surfaces.

While swapping out the wishbone for a replacement and re-setting the brakes, , I noticed that the lever for the front-right brake (the one causing the 'bangs' ) could pulled all the to about 10'oclock without applying any brake pressure. At first I assumed the cause was missing operating pin shims (which were missing). However, later inspection showed the pin (that holds the brake lever to the shaft) had sheered off on both ends (2nd, 3rd picture).

I also re-arched the brake shoes, suspecting maybe they were catching on the drum in some odd way.

Apologies for the long story, but interested in any ideas as to what could have happened, or of similar experiences (?).

 

[larrys40]

Interesting occurance. Probably cause by possibly a couple of things .
The wishbone broke probablyy because the perch nuts were not tight and it worked the wishbone. Also it is possible your backing plate bolts were /are loose which can cause the front brake pin to bind and lock up the brakes as it would bind in the inside of the spindle bolt.
Its important to make sure the backing plates are tight and all your brake and other parts are restored to spec and brakes restored and centered/adjusted properly

Larry Shepard

 

[TomballMottershaw]

I had the same issue on my 30' Tudor.
The top right side was was broken when I got the car.
I cleaned it, beat it back, and welded it, it held till found a good wishbone.
Stop doing the donughts and jTurns.... Till properly fixed.
Now Swapping it out takes a good air hammer... Sledge..

 

[Chuck Sea/Tac]

Within 12-15 thousand miles of rebuilding my brakes, including cast iron drums, I evidently had one actuating pin that was broke, and I snapped the 2nd one,while making a panic stop. Unfortunately, they were both on the left side, so I spun out and hit a guard rail.
Now I've tack welded the cam shaft to the arm ( which is easily ground off) to prevent another ugly situation, not to mention, piece of mind.

 

[apbright]

Yikes, that could have been really hairy were to have happened at the wrong place + time. From the fact that you're writing about it I'm inferring at least you tuned out alright.

I have to admit that, as I had no spare lever pins, I am using a 1/4 stainless steel bolt (w/nut, washer, & lock washer) as a stand-in. Not being a metallurgist, I have no idea whether that has a higher strength than a proper lever pin, but having re-arced the shoes, it no longer seems to be grabbing, and thus seems to work for now. I do like the idea of welding the lever to the shaft, though. Have to buy that TIG/MIG welder it seems...