Brake Valve - Rear | Page 2 | FerrariChat

Brake Valve - Rear

Discussion in '365 GT4 2+2/400/412' started by samsaprunoff, Mar 30, 2020.

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  1. samsaprunoff

    samsaprunoff F1 Rookie
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    Jun 8, 2004
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    Edmonton, AB Canada
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    Sam Saprunoff
    Good day Raemin

    I said "nasty" as a play on words... meaning Paul is somewhat teasing me in that he is enjoying some nice Spring weather, whereas, I am not. In your case, you are even making me feel worse, as we will be lucky to get to +3C as a daytime high over the next week.

    As for your rear brakes locking... I would think that your rear brake limiting valves are not working as they should. From what I have read so far and from what I can understand by examining my valve, the rear brakes should never lock up. I say this, as one of the features of this valve is to limit the maximum brake fluid pressure as seen by the rear brake caliper pistons. This would be a good thing, as locking the rear brakes could cause the car to "spin" during hard braking. Given what I know now, I would suggest you have someone remove and examine the rear valves, as the internal piston could be stuck, internal seals not working, etc and thus not doing their job properly.

    Cheers,

    Sam
     
  2. pshoejberg

    pshoejberg Formula 3
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    Dec 22, 2007
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    Peter H
    Just a general warning to all that plan to dismantling these pressure control valves. Treat the seals very carefully if you for any reasons plan to reuse them. The rubber seals are very sensible to any chemicals other than brake fluid and might be permanent damaged if cleaned in any other hydrocarbon based fluid. Even WD40 can damage them (Ask me how i know...-:)) Good luck finding replacement seals to all.

    Best regards Peter
     
  3. samsaprunoff

    samsaprunoff F1 Rookie
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    #28 samsaprunoff, Apr 6, 2020
    Last edited: Apr 6, 2020
    Indeed, this is sage advice. Seals that come into contact with brake fluid are made from a different material than seals coming into contact from oil, etc. From what I have seen EPDM (ethylene propylene diene monomer) is the material used for brake seals.

    Cheers,

    Sam
     
  4. samsaprunoff

    samsaprunoff F1 Rookie
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    Jun 8, 2004
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    Sam Saprunoff
    Good day All,

    With the Covid-19 lock-downs and restrictions put in place for many businesses I am finding it challenging to find the wiper seal used in these valves. Since the valves are made by Ate I am confident that Ate used the same seals in some other Ate brake equipment. The problem is how to find which equipment used these seals and/or if these seals are available to purchase. Given that I can see spending a lot of hours reviewing, analyzing, and testing a number of possible seals I decided to simply buy the seal Kits from PMB and be done with it and move on to other tasks. The PMB seal kit also includes the spring chamber gasket and so buying the kit also saves me from making these gaskets. The seals are in stock, but since the mail system is moving a bit slower these days I do not expect to have the seals in my hands for at least 2-3 weeks. I will update this thread with how the PMB seals compare/match up.

    Cheers,

    Sam
     
  5. rovexienus

    rovexienus Formula Junior
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    Jun 10, 2010
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    Sainte Colombe, France (near Lyon)
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    Jean-Michel Savary
    Hi Sam, just a suggestion, perhaps ATE Classic would help identifying the kit components? Unless they do not want anyone to maintain this item of course.
     
  6. samsaprunoff

    samsaprunoff F1 Rookie
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    Sam Saprunoff
    Good day Jean-Michel,

    From the Internet research I have done on these valves it appears that a rebuild kit (e.g. seals) was never available by Ate nor Manufacturers that used these parts. Most speculated that the reason for this was because of the valve's adjustability and that it's setup was specific to the Auto manufacture's specifications (model specific). Thus Ate did not want the units rebuilt in case the resulting rebuild was no longer in spec and thus could create a brake safety concern and so could be potential liability for Ate. Now, all of this is conjecture and so who really knows the reason for not supplying the seals separately? However, the fact is that a rebuild or seal kit was never available by Ate or other third party brake component manufacturers and so there must have been a reason.

    As for Ate Classic.. Interestingly, I could not find one single Internet post or thread that spoke positively of the Ate Classic department. The comments I found were similar to those made of Ferrari Classiche, where these specialty departments' focus were specific to high end, specialty, and/or big pocket customer restorations. That being said, it does not hurt to try and reach out to Ate Classic, as the worst case they can simply say no or that they cannot help. I will e-mail them and will post their response.

    Cheers,

    Sam
     
    rovexienus likes this.
  7. rovexienus

    rovexienus Formula Junior
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    Jean-Michel Savary
    Thanks Sam, I understand
     
  8. samsaprunoff

    samsaprunoff F1 Rookie
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    Good day Jean-Michel,

    I had a quick response to Ate Classic:

    I am very impressed at how quick they responded and especially so given the times we are in. However, as what was eluded to in my Internet searches, the seals are not separately available nor will they provide any seal dimensions. Although this is disappointing it is not entirely unexpected and so the seal search continues. Thankfully PMB's seal kit is available and there is a high probability that it should have the correct seals for these valves. Once I receive the PMB seal kit I will post up further deals and how it matches up to these valve seals.

    Cheers,

    Sam
     
  9. rovexienus

    rovexienus Formula Junior
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    Jun 10, 2010
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    Sainte Colombe, France (near Lyon)
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    Jean-Michel Savary
    Hi Sam, thanks for the update.
     
  10. samsaprunoff

    samsaprunoff F1 Rookie
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    Jun 8, 2004
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    Sam Saprunoff
    Good day All,

    Just an update to this thread...

    I received the seal kit from PMB and for the most part it is the seal kit that I was looking for. I say mostly, as the two supplied o-rings are not exactly the same size as the originals, but I think they will work fine. The larger/outer seal will not be an issue, but the smaller one I just need to double check the fit and tolerance. I will report back on how this goes when I start the refresh process. The most important and critical seal is the wiper/c-cup seal and the supplied on looks to be an exact match... So, all is good. So... If you need to do this PMB's seal kit is $59 USD for each one and can be found here:

    https://www.pmbperformance.com/diy-caliper-parts--acces/Pressure_Regulator_Kit.html

    I have attached some pictures of the old seals and how they compare to the PMB supplied ones. In all pictures, the left side is the original seal. The small little bullet head is not used by our valve and so it can be ignored.

    I am hoping to start the refreshment process in a few weeks. I am planning on lightly blasting (soda first) the external housing and spring container with special attention to the latter, as I do not want to disturb the original epoxied adjustment bolt. Afterwards I will be repainting the items using Satin-black caliper paint. I opted for caliper paint (from VHT), as this paint is more resistant to brake fluid which could drip, etc during the installation and bleeding process. I will test how well the VHT paint holds up to brake fluid and if it is so-so, etc then I will be using some specialty 2-part epoxy paint that I will be using for the undercarriage and this stuff is virtually impervious to almost any chemical or condition thrown at it.

    I will follow up with pics when I am done.

    Cheers,

    Sam

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