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Acty Brake Upgrade to Discs

Discussion in 'Performance' started by Acty 660cc, Jan 4, 2012.

  1. Acty 660cc

    Acty 660cc Member

    Hi All

    I replied to a post earlier, but think it was an old on and archived, so thought this might be of interest anyway so have posted it in the "Performance" section for info / refference - might be of interest.

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    hi there,

    i have a 1981 honda acty which originally had drum brakes all round. I have just spent some time swapping the old 545cc engine for the newer 660cc tripple, 12 valve. the donor vehicle being a 1993 also had disc brakes on the front, so i stripped the complete front suspension from the donor vehicle along with the rear beam including suspension and larger drum brakes for the back.

    Ive swapped everything in and just need to get some different brake hoses mde up to complete it.

    To upgrade to discs at the front, i fitted the complete disc, hub, mcphereson strut assembly from the donor vehicle onto the exisitng bottom arms - there were some complications however:

    Front suspension:

    1. I had to use the old strut top, as the new strut tops were too big to bolt to my inner wheel arch, so i had to strip the strut down and change the top bearing - it fitted directly onto the "new" strut with no problems. Be sure to change the swivel bearing aswell else the smaller strut top bearing binds to the larger casing, so just swap the lot from the top of the struts. (use a spring compressor for this, dont just undo the top nut as the spring has a slight pre-load and might try and jump off and whack you)

    2. On the newer acty vans, the steering arms approach from the front of the bottom arm. On the old vans the arms approach from the rear of the bottom arm, so they were the wrong way around. To get round this i fitted the passenger strut to the driver side and vice versa. Seems to have worked fine, only differnece is the caliper is now on the leading edge rather than the trailing edge - dont think that will make a difference.

    3. The dimensions of the position for the mounting points for the steering arms is slightly different, so when i put the steering arms on and adjusted them the front wheels were both turned outwards, so i had to cut the steering arm weld a 40mm section into each to lengthen them, all adjusts up fine now. On the plus side the old track rod arms fitted straight into the newer hubs no problem. (couldnt just swap in the new arms as the steering rack end is different, and they are too short anyway)

    4. The small 10 inch wheels would not fit over the calipers, so i now run 13 inch civic wheels - which should be another massive improvement over the old small wheels.

    5. It appears that the lower arms could do with being 10mm or so longer as i have some negative camber \ / when the van is unloaded - but i have a heavy camper body which goes on the back, so as the suspension is pushed down this improves, im debating whether to cut and lengthen the bottom arms.

    Rear beam differences:

    6. Rear beam track is all the same, it bolts in without event - but the damper mounts are different, i cut the mounts up from the tops of the old dampers and modded them onto the new dampers where they bolt to the body, the lower mounts also need cutting, bending towards the centre of the vehicle and re-welding. works fine now.

    7. Rear brake flexi hose that drops to the rear beam needs to be lenghtend as the rear beam has a slightly different curve to it.

    8. The handbrake cables are different - on the new beam they come out of the drum back plate and go forwards, one from each side. On the old beam they ran along the beam to a common point from each side on the drivers side (UK) and then one cable went forward to the cab. I havent sorted this yet but im planning to use a 1 to 2 bar from a citroen zx or similar, shouldnt be too bad to sort out.

    As you can see theres a far amount to it, might be other ways to get discs on the front but if you use acty parts from a newer vehicle its a lengths process.

    I have a camper body (Romahome) that goes on my acty and i ve had instances where ive been going down a hill with a junction at the bottom, standing up on the brake pedal, clicking the handbrake on nervously to get it to stop - so i thought some front discs were a must to get rid of my brake fade problems.

    if you do it you need to address the rear axle aswell becuase you will need larger front wheels to go over the calipers, so need larger wheels on the rear aswell really.

    its a fair bit of work and you need to be pretty competent to get it all sorted but im sure that the benefits of discs, and bigger wheels will be well worth it. The new engine also has a tapping for a brake servo, the donor vehicle had a servo but it was a direct unit fitted to the end of the brake pedal - old acty dont have space for this so i need to find a remote servo to go under the bed somwhere - project for another time.

    good luck!!!


    Acty 660cc
     

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