Joined: Aug 2017 Posts: 174 Threads: 53
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Hello all,
The uncoupled handbrake operated front brakes on my Chummy are really quite poor.
The handbrake lever seems to have too much movement and runs out of travel before the brakes are applied sufficiently.
I've already adjusted the nut on the handbrake, but I'm running into the issue of the brake(s) binding when the wheels are turned, so I don't really want to adjust it any further.
It almost seems like the handbrake needs to be more upright, but I don't really have any more thread to play with where it attaches to the cross member, so can't pack it out with washers.
Am I missing anything obvious? Is this a symptom of something else amiss? Can the front brake levers be the wrong way round as they are sometimes on the rear?
Any pointers much appreciated!
Joined: May 2018 Posts: 2,110 Threads: 110
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Location: Llandrindod Wells
Car type: 29 Special, 30 RK, 28 C Cab
Hi Rupert
One likely explanation for poor uncoupled front handbrake performance is the pivot at the bottom of the handbrake bracket. Three possible areas of wear: the pins, the pivot and the bracket itself. The pins can be a loose fit due to wear, the pivot also wears. Replacements for both of these are available from our cherished suppliers. But also the holes in the bracket can get enlarged and will need welding up and re-drilling.
It may also be possible that the ratchet is the wrong one. Later coupled brake cars have a different ratchet but can be erroneously fitted to early cars.
Finally don’t be tempted to shorten the stop on the gearbox which holds the ratchets. It’s there to prevent the handbrake hitting the fabric coupling!
Cheers
Howard
Joined: Aug 2017 Posts: 174 Threads: 53
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Thank you that's helpful - the pivots are definitely new but I can't recall if the pins are too so I'll check that and for play more generally.
Is there a straightforward way of identifying which ratchet I might have fitted?
Joined: Aug 2017 Posts: 613 Threads: 19
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Location: Hampshire UK
Hi
If the front brakes are binding when the steering is moved this suggests to me that the problem might be due to accumulated wear at the wheel end.
What angle are the brake cam levers when the brakes are fully applied ? Ideally they should be facing slightly forwards with the brakes off, then move to near vertical or maybe slightly (but no more) backwards when they are fully on. This places the lever's pivot ball immediately underneath the line of the kingpin so that turning the steering has minimal effect on cable tension.
You might need to experiment by shimming the end caps of the brake shoes or pack around the shoe pivot to achieve this, as there is no adjustment.
Joined: Aug 2017 Posts: 174 Threads: 53
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Great thanks very much all for the advice - plenty of things for me to check there. I've had an initial look and there's no obvious play in anything at the handbrake end and the ratchet looks correct.
The cars not in a massively accessible spot currently so when the weather clears up a bit I'll get the front end properly jacked up for a proper investigation at the front end.
Joined: Aug 2017 Posts: 986 Threads: 6
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Location: Scottish Borders
Another area to check is the mounting of the radius arms onto the crossmember. That needs to be tight.
I have modified our handbrake to give more travel. There are three washers between the handbrake pivot and the front crosmember. This makes the hand brake move further forward when released.
More significantly our handbrake ratchet mounting has also been modified.
Originally the speedo was driven by a belt on the propshaft. This was then modified to the worm & wheel on the gearbox output shaft. This is in a housing on the back of the gearbox. When this was done the handbrake travel had to be restricted tp allow space for the housing, otherwise the handbrake would foul the propshaft. The travel was restricted by adding the spigot on the ratchet mounting bracket which acts as the handbrake stop.
We have fitted a Hardy Spicer propshaft from A7 Componenents so the fabric coupling is no longer there to foul the handbrake. With this in place I was able to shorten the spigot to allow the handbrake more travel.
This works very well, and I have fitted long levers on the front brakes to increase the braking performance.
It is no longer possible to pull the handbrake to the limit of its travel.
Jim
