Joined: Aug 2017 Posts: 625 Threads: 19
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Location: Sheffield South Yorks
Car type: 1932 RN saloon
Dave,
Has the fact that the king pin and the radarm bolt were broken also loosened the rivets attaching the front crossmember to chassis rails and the centre longitudinal member?
Dave.
Joined: Aug 2017 Posts: 762 Threads: 32
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Location: Beautiful Northumberland
Car type: 1933 RP Saloon (aka Mildred)
I had a similar problem earlier in the summer and it turned out with that I had tried to be too clever with tightening up the adjustment. I slackened everything off just a little to give more slack in the cables and it seemed to allow the left to right adjustment and front to rear to just work together rather than grab at first application of the brakes.
Andy
Enjoy yourself, it's later than you think!
Joined: Aug 2017 Posts: 1,700 Threads: 46
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Location: Auckland NZ
Car type: 36 Nippy, 31 RM, 38 Special, 24 Works Rep
With that amount of force it is likely that the end of the radius arm which houses the brass cups has been spread allowing the cup to move within the arm. No matter how tight the centre bolt is done up movement will still be present under braking, get your friend to remove the arm's and check the fit of the brass cups, if this is the problem I would expect it to cause worse grabbing in reverse though. It seems obvious that something related to the accident has caused the problem, what else has been changed to repair the damage, to break a king pin and radius arm ball other components must have been damaged, axle, stub axle crossmember, steering and track rod arms? Is the new king pin a good fit in the axle, with that amount of force I would expect the eye would be spread and axle possibly bent.
Black Art Enthusiast
Joined: Oct 2017 Posts: 1,498 Threads: 54
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Had an update today, the owner has had all 4 brakes drums off and checked they are all round. He also cleaned the drums and shoes with emery cloth after which the brakes were initially almost non existent. then it was soon back to th grabbing problem.
Joined: Aug 2017 Posts: 2,382 Threads: 33
Reputation:
36
Location: Deepest Frogland 30960
Car type: 1933 RP Standard Saloon
Dave, whilst the drums may well be round, has the relationship between the drums, the brake shoes and the cams been verified? If you cover the lining material with chalk you can very quickly determine which parts of the brake shoe are actually contacting the inner surface of the drum as where it touches will be cleaned off. I suspect that the contact area isn't as great as it should be. The leading shoes may be the culprit as they have a self-servo action.
Just my two-penn'orth
Bruce
Joined: Oct 2017 Posts: 1 Threads: 0
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I had a problem with rear off side brake grabbing on when moving at slow speed either forwards or backwards. In addition there was a “metallic clunk” noise as if a brake shoe was hitting the back plate.
When travelling at speed, providing I had “test” applied the brakes in a safe place when setting out, I found there seemed to be no problem of grabbing.
I did the usual things of filing the leading and trailing edges of the brake lining - a gentle slope for the first half inch either end of the brake lining. Also gently filed off the sharp edge of the brake lining.
Checked various dimensions to see what might be causing the shoe to rock over and hit the back plate
Ultimately after extensive detective work, I noticed that there was a bright metal rub line running around inside the brake drum at the edge of the rubbing face furthest from the back plate. I noticed that the brake lining hung over the edge of the shoe a tad on the side furthest away from the back plate. Filed it back the brake lining to be flush with the brake shoe. Cured ! No more grabbing of brakes and no “metallic clunk” of the shoe hitting the back plate.