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Thread: Changing Brake Discs on my 63 BJ7

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    Changing Brake Discs on my 63 BJ7

    Hello Motor Heads,

    I am a new Healey owner of the above. I am about to undertake my first big project on the car and would appreciate advice. Both Girling front calipers are leaking fluid. Rebuild kits are on their way along with the O-rings that seal the two caliper halves-the calipers are not obviously leaking around the pistons. I am ok with "splitting the halves and hopefully this part of the job will go well. After some research I have decided to give the expensive EBC green pads a try and change out the rotors. The old rotors are technically useable with relatively shallow concentric grooving. However honestly I am totally underwhelmed with my big Healey's stopping power and would like to do what I can to improve upon that by replacing the discs as well. Here is where I would like some advice. I do not have the Healey tool to remove the grease cap. I was planning on screwing on the appropriate nut and prying the cap off with two screw drivers. Does this sound right? If so, what is the best way of reinstalling the cap? Also with regards to the hub/disc unit, I do not have the tool to remove it. In most of my learned fellow Healey enthusiasts opinion, does the unit generally slide off of the hub axle with some gentle back and forth tugging or does this tend to be a problem? Since we are rapidly approaching prime Healey driving weather here in North Carolina, I am considering just rebuilding the calipers and stopping there for now. I realize that I can deal with the discs and new pads at a later date.

    Thanks for your help,

    Bill

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    Jedi Knight Healey Nut's Avatar
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    Re: Changing Brake Discs on my 63 BJ7

    Get a 5/16 fine thread coupling nut & a short piece of 5/16" threaded rod . Screw the coupling nut onto the grease cap stub screw the threaded rod into the coupling nut . Then using another nut and a large fender washer or washers create yourself a small pulling tool to extract the grease cap .
    once the axle nut is removed which you need a 1 1/8" socket for if I remember correctly the disc and bearings should come off with some gentle persuasion . Dont loose the shims !!!
    "If it aint broke ....dont fix it "
    " Thats not an oil leak ..........its a special automatic British rustproofing system "
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    Re: Changing Brake Discs on my 63 BJ7

    I based my slide-hammer Remover/Installer on a 5/16-24 coupling nut with appropriate bolt:
    AxleCapRemover.jpgAxleCapInstaller.jpg
    Steve Gerow
    Altadena, CA, USA
    Maker of most complete Big Healey rear disc kit
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    Re: Changing Brake Discs on my 63 BJ7

    Re-packing the bearings and checking the shim clearance is the more intimidating part of the front brake job for the new owner/mechanic.
    Strongly urge purchase of Norm Nock's Austin Healey Tech Talk book for great info on this and many other topics. It's great rainy-day reading.
    See this (scroll down):
    https://www.britishcarspecialists.co...lications.html
    Steve Gerow
    Altadena, CA, USA
    Maker of most complete Big Healey rear disc kit
    Check out my galleries:
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    Re: Changing Brake Discs on my 63 BJ7

    Quote Originally Posted by Healey Nut View Post
    Get a 5/16 fine thread coupling nut & a short piece of 5/16" threaded rod . Screw the coupling nut onto the grease cap stub screw the threaded rod into the coupling nut . Then using another nut and a large fender washer or washers create yourself a small pulling tool to extract the grease cap .
    once the axle nut is removed which you need a 1 1/8" socket for if I remember correctly the disc and bearings should come off with some gentle persuasion . Dont loose the shims !!!
    ^This. After you remove the calipers, check the end float of the hubs/rotors by grasping the hub and pulling and pushing; you should feel a tiny 'smidge*' of end play; any more than that and you may need a different shim pack and possibly new bearings and races (inspect both for damage or heat coloring, and repack with disk brake grease and new seals). Inspect the splines on the hubs and inside your wheel hubs--assuming wire wheels here--if the splines don't have a flat spot on them--i.e. they are worn sharp--you'll need new hubs and possibly wheels. Don't skimp here, if the splines are worn you can lose a wheel.

    * There's a book value for this, a couple to three thousandths IIRC using a dial micrometer, but last I did mine I used shims to get just barely perceptible end float, and I've put at least 60K miles on them with no issues. Typically, you need 0.030" of shims, give or take a thou or two.

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    Re: Changing Brake Discs on my 63 BJ7

    To All,
    Thanks for what I feel is excellent advice. I probably would have come up with the above slide puller in about 100 years.

    Bill

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    Re: Changing Brake Discs on my 63 BJ7

    Just finished installing new splined hubs and bearings on my BJ7 - bit of a pig having to remove the studs/bolts from the splined hubs and then install them in the new hubs - but you should not have to do that if your splines are OK. When I changed the discs (rotors) some years back I gently tapped off the discs and then installed the new ones using a tube placed over the studs/bolts and hammered the tube going around each in turn easing the discs over them until they registered against the hub, I have a large vice so supported the hub on a piece of wood on the bed of the vice and the splines were protected in the jaws with several wraps of cloth, the wood is necessary to prevent the front of the hub from being damaged during the hammering process. If you do not have to change the bearings - you should still change the seals at the rear.

    It pays to get a selection of shims, I have a load of each of the major 4 sizes, gathered over the years, and lay them out on a sheet to make selection easier.
    This time I installed the hubs dry (with a little grease on the seal) with extra shims of known thickness as the book, measured the end float with a dial guage and adjusted the shim packs to suit - dry installed the hubs again, checked for ease of turning and any end float then dismantled and greased everything up and reinstalled. It is a PITA but it is better than guessing which I had done before, because that is even worse.



    Bob

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    Re: Changing Brake Discs on my 63 BJ7

    Bob,
    Above was helpful. Between the above responses and what I've been able to read, I believe that I'm starting to understand what is involved with this job. The calipers have been cleaned, split and rebuilt. I will go on to remove the hub/disc assembly this winter and replace/repack the bearings as indicated. A new seal will be installed. On the left hub there has been some "sharpening of the splines" with subsequent decreased flattening. As indicated above, they may need to be replaced. I will have an experienced set of eyes take a look at them.

    Thanks for your help,

    Bill

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    Re: Changing Brake Discs on my 63 BJ7

    If they are available and You aren't concerned about period correct, braided flex lines add a ton of pedal firmness.

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    Re: Changing Brake Discs on my 63 BJ7

    Bill

    You can tell how far the splines are worn - put a wheel on but do not tighten up the spinner, wedge a suitable length of stick between the brake pedal and your seat to apply the brakes and then rotate the wheel back and forth on the splines - when both wheel and hub are new there is no movement. Mine were so bad you could hear the clunk when the brakes were applied when stopping. Doh just realised that you can not do that if you have stripped things down. When you remove the hubs try them in a good wheel if you have one. It would pay to determine how bad things are before you change the discs over. I now have new tyres, wheels and hubs all round - it was a long time coming but the best thing I ever did for the handling and no clunk on braking.



    Bob

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