Hand brake/Park brake ratchet slipping | FerrariChat

Hand brake/Park brake ratchet slipping

Discussion in '348/355' started by gatekeeper, Sep 21, 2021.

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  1. gatekeeper

    gatekeeper Rookie

    Jun 8, 2021
    33
    Full Name:
    Paul
    Hi. I've read that the F355 handbrake could be a bit suspect even when new, but I'm struggling to get mine to stay on. Most the time the ratchet will slip off causing the brakes to release.

    Upon inspection I can see why they've never resulted in a positive lock, since the ratchet teeth are pointing slightly down, therefore there is a risk of the locking arm simply slipping off the tooth. Of course with a 24 yr old car, these teeth have become slightly worn therefore making the issue worse. Why didn't they angle the teeth upwards in the first place??? :) I've tried cleaning the teeth to ensure there is no grease on them, but its still an issue. I've even tested the mechanism on a bench with some load added to the cable point and the lock simply slips off the tooth.

    Does anyone have any tips to either reshape the teeth or replace the ratchet with an alternative? I'm thinking that unless I bought a brand new handbrake unit, then I'm going to have the same issue with another 24 yr old part.


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  2. PhilB

    PhilB Formula 3
    Owner Silver Subscribed

    Feb 17, 2004
    2,311
    Southern New Jersey Shore
    Full Name:
    Phil
    Forget the handbrake and use 1st gear.
     
  3. Qavion

    Qavion F1 World Champ
    Silver Subscribed

    Feb 20, 2015
    14,167
    Sydney
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    Ian Riddell

    Superformance offer a ratchet repair kit which may be compatible with the 355.
     
  4. gatekeeper

    gatekeeper Rookie

    Jun 8, 2021
    33
    Full Name:
    Paul
    Many thanks Ian.

    I've just emailed Superformance to see if its compatible....It certainly looks the same.

    If it is, I may have a go at modifying the existing one to see if I can 'improve/reshape' the original design to make it work better...The existing design certainly looks like it was signed off on a Friday afternoon :)
     
  5. gatekeeper

    gatekeeper Rookie

    Jun 8, 2021
    33
    Full Name:
    Paul
    Unfortunately, although Superformance were unable to confirm that the part was compatible with a 355, they also they said that they no longer stock the part and are unable to obtain anymore from the factory :(
     
  6. Qavion

    Qavion F1 World Champ
    Silver Subscribed

    Feb 20, 2015
    14,167
    Sydney
    Full Name:
    Ian Riddell
    Sorry to hear that, Paul.

    I think others have had varying success reshaping/filing the teeth. I don’t know if you can heat treat the steel to make it harder.
    Is the pawl similarly worn? Are there springs on the pawl? Perhaps they can be replaced/adjusted?
     
  7. gatekeeper

    gatekeeper Rookie

    Jun 8, 2021
    33
    Full Name:
    Paul
    There is a spring on the Pawl, which I'm thinking I could try and increase the tension to see if that will help.

    I'm also looking around for some alternative types/manufacturers to see if its possible to fit/fabricate a different toothed quadrant into the Ferrari unit which will improve the locking.

    Will report back on how I get on.
     
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  8. GiulioP

    GiulioP Karting

    Jun 12, 2019
    94
    Full Name:
    Giulio Palazzo
    Having the exact same issue with my 1995 348 spider. The ratchet part is interchangeable with 456, 575, 550, enzo and 355. New part#154095
    Keep me.posted!!

     
  9. taz355

    taz355 F1 Veteran
    Owner Silver Subscribed

    Feb 18, 2008
    6,009
    Indio Ca/ Alberta
    Full Name:
    Grant
    Mine was not great but after changing the shoes it has been working very good for about 7 years
    It might be because now it engages at 1/4 pull and is grabbing in a different area
     
  10. GiulioP

    GiulioP Karting

    Jun 12, 2019
    94
    Full Name:
    Giulio Palazzo
    That could be another possibility. I did see the teeth on mine and they were scored though.

     
  11. gatekeeper

    gatekeeper Rookie

    Jun 8, 2021
    33
    Full Name:
    Paul
    I've managed to sort the issue by spending a few hours making a new Pawl.

    You can remove the old one by drilling the rivet out and as you can see in the photo the end which engages with the ratchet is very rounded. I used this as a template on some 5mm mild steel and with a bench grinder, made a new one but included a a clean and sharp point which would engage with the ratchet. This engages really well and I used a bolt to replace the rivet. You need to grind down the bolt so that it sits within the handle. The handbrake locks perfectly now.

    Time will tell how well it wears since I suspect the sharp point on the pawl could become rounded, but if press the button when using the handbrake, I'm hoping it should be fine.

    Hope this helps others
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  12. 308 GTB

    308 GTB F1 World Champ
    Rossa Subscribed

    Feb 7, 2002
    11,705
    New Jersey
    Full Name:
    Barry Wolinsky
    A new pawl for Paul. Well done!

    Barry
     
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  13. GiulioP

    GiulioP Karting

    Jun 12, 2019
    94
    Full Name:
    Giulio Palazzo
    Nice!! Keep us posted.

     
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