ferny
Club Retro Rides Member
Posts: 979
Club RR Member Number: 13
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Sept 26, 2019 18:22:44 GMT
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So, that's the brake adjuster from the herald. It failed when the car was jacked up with the handbrake on. I can't see that as a genuine reason for failure. The threads inside the aluminium housing have stripped. The 'gunk' on the thread is an anti-seize. The part is a few years old as I replaced them at some point, but no idea when. If it's relevant, the shoes on this side have more wear and are cracked, presumably from getting too hot. The ones on the other side are fine. The braking system worked fine and would happily lock up all four wheels at 40mph - never tried a faster speed and had no plans to try at that one either until a car pulled out in front of me! I consider myself lucky to have it fail when stationary rather then in movement. It's a single circuit system and recently had a servo fitted.
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Last Edit: Sept 26, 2019 18:26:25 GMT by ferny
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Sept 26, 2019 21:20:29 GMT
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Failed as in collapsed to the fully unadjusted position purely from the pressure of the followers on the cone?
Unless you know these are OE Girling parts (which last indefinitely with a bit of greasing) I'm tempted to suggest that this one might be a will-nearly-fit copy part made to a poor standard?
Nick
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1967 Triumph Vitesse convertible (old friend) 1996 Audi A6 2.5 TDI Avant (still durability testing) 1972 GT6 Mk3 (Restored after loong rest & getting the hang of being a car again)
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ferny
Club Retro Rides Member
Posts: 979
Club RR Member Number: 13
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Sept 27, 2019 5:37:44 GMT
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Yep, that's how it failed Nick. We replaced the tyres at work and I found out it had failed when leaving and I had no brakes. The above picture is the quality of the replacement, bought from specialist based in the middle of the country but not the overly priced one. It also had a piston/follower missing.
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Last Edit: Sept 27, 2019 5:39:07 GMT by ferny
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Darkspeed
Club Retro Rides Member
Posts: 4,642
Club RR Member Number: 39
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Sept 27, 2019 6:14:11 GMT
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I would suggest that at sometime in its past someone tried to unwind it further than its limit - The adjuster screw was wound all the way back but as the drum was still not moving they heaved on the screw further and sheared all the threads. However there was still enough bits of aluminium left in the bore for the adjuster to screw back in until heat and vibration and multiple applications of the brakes made it give up what sticktion it had left.
The little pistons stick in the bores and people seem to think that yanking on the adjusting screw will somehow free them - LOL
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Sept 27, 2019 8:33:58 GMT
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I would suggest that at sometime in its past someone tried to unwind it further than its limit - The adjuster screw was wound all the way back but as the drum was still not moving they heaved on the screw further and sheared all the threads. However there was still enough bits of aluminium left in the bore for the adjuster to screw back in until heat and vibration and multiple applications of the brakes made it give up what sticktion it had left. The little pistons stick in the bores and people seem to think that yanking on the adjusting screw will somehow free them - LOL could also explain why it has anti seize on it, someones bodge to compenstate for partially stripped threads. In good condition that length of thread should take a couple of tons of load its either a very poor quality part or damage caused by mistreatment.
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ferny
Club Retro Rides Member
Posts: 979
Club RR Member Number: 13
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Sept 27, 2019 16:17:41 GMT
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Deffo not mistreated as I fitted it some years ago. Which has just made me realise I've had the car 13 years! I put the anti seize on there when I put it on and adjusted the brakes two or three week prior to failure. Everything worked fine then. I've replaced both sides with new now and all bits on both were free moving.
It's a puzzler!
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Sept 27, 2019 17:24:58 GMT
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Hi, In that case I would say it's poor quality Aluminium that has degraded over time.
Colin
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ChasR
RR Helper
motivation
Posts: 10,188
Club RR Member Number: 170
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Sept 27, 2019 21:26:32 GMT
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Darkspeed's analogy sounds right when you think about how it works.
I've seen them seize, but never break apart. If it had a County badge on the box when you bought it, I'm sorry, but it was never going to last.
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