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Rear brakes

Posted: 28 Sep 2013 15:01
by bmcecosse
having pulled apart the RH rear brake (9") to free off a stuck piston - is there any special trick to resetting the 'self adjust' mechanism ? Put it all back together (exactly as it came apart..) - applied the footbrake hard - then tested the handbrake - doing nothing! I opened up again -and manually moved the self adjust along, and it seems 'better' - but should I have to do that??

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Posted: 28 Sep 2013 16:39
by Workshop Help
Yes.

Mildred Hargis

Posted: 28 Sep 2013 17:49
by bmcecosse
Surely it should ratchet up by itself???

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Posted: 28 Sep 2013 18:02
by busheytrader
I've had issues in the past where some light surface rust on the components caused lots of "stiction". It stopped the handbrake and ratchet mechanism from working properly.

A wire cup attachment in a drill cleaned up the stripped compoents and all was well again.

Has your piston got stuck again?

Adam



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TR7 V8 DHC Jaguar Solent Blue. 9.35cr Range Rover V8, Holley 390cfm, JWR Dual Port, 214 Cam, Lumention, Tubular Manifolds, S/S Single Pipe Exh, 3.08 Rear, 200lb Spax & PolyBushes all round, Anti- Dive, Strut-Top Roller Bearings, Capri Vented Discs & Calipers, Braided Hoses, 4 Speed Rear Cylinders, Uprated Master Cylinder & Servo, AT 14" 5 Spokes or Maestro Turbo 15" Alloys, Cruise Lights, S/S Heater Pipes, Replacement Fuel Tank. No Door Stickers. Mine since July 1986, V8 from 1991 courtesy of S&S V8 conversion and big brake kits.

Posted: 28 Sep 2013 18:22
by bmcecosse
No - the piston is nice and free... It's all nice and clean in there - although I resisted the urge to put any lub on the moving parts - reasoning it would just attract brake dust and end up as sludge.

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Posted: 28 Sep 2013 21:22
by Beans
Connect the handbrake cable after bleeding the brakes

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Posted: 28 Sep 2013 22:34
by Hasbeen
Polish up all parts that rub on each other as recommended by Busheytrader, with a wire brush, so they will slide.

You should still be able to get powdered graphite.

If you can a puff or two of this during assembly will aid movement. Don't use too much, it doesn't need it, & you don't want it on your linings.

Hasbeen

Posted: 30 Sep 2013 06:07
by Howard722
There is a pivot pin that secures the handbrake arm to the horizontal actuator plate inside the drum-this can seize making the mechanism poor in function.
The self adjuster ratchet teeth can wearout and this causes problems, also both ratchet parts need to move freely on their pins with good spring action.

Enjoy& regards Image

Posted: 30 Sep 2013 09:19
by bmcecosse
Thanks all - everything seemed to be moving ok - certainly that pivot pin. The handbrake was never an issue - the car won't move in 1st gear against the handbrake! Not sure if this indicates a weak clutch - or a good handbrake.........

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Posted: 30 Sep 2013 13:24
by FI Spyder
To put the drum back on you have to have them adjusted "in". Some people have a hard time removing the drum because the one edge (can't remember if it is leading or trailing) is almost if not touching the surface of the drum. If there is a slight wear on the drum that edge catches on the drum. Any ways to put the drum back on the shoes are adjusted in (especially if you just out new ones on). With everything back together you now have to manually adjust the shoes out until they are just dragging. This is done with a large screwdriver (or brake adjustment tool) through the back of the brake by levering the screwdriver on the star wheel. The automatic adjusters will do it but it will take forever as they operate one tooth at a time every time you brake hard(er) in reverse then forward. Manually setting them gets them in range so the automatic adjuster can make the last bit of adjustment. The brakes have to be set right for the emergency to work as you don't have a lot of room for error in the mechanism.

- - -TR7 Spider - - - 1978 Spitfire- - - - 1976 Spitfire - - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra - Yellow TCT
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