360/430 bleed block installation standard (new?) | FerrariChat

360/430 bleed block installation standard (new?)

Discussion in 'Technical Q&A' started by vrsurgeon, May 6, 2018.

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  1. vrsurgeon

    vrsurgeon F1 World Champ
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    Curt
    #1 vrsurgeon, May 6, 2018
    So I had my clutch replaced about a week ago. Got it home and the clutch pedal was alot "lighter" than prior with an uptake point way down near the bottom of travel.

    So I decide I'm going to bleed the system. Could be some air in the system right? As I'm taking off the tray I notice clear fluid coming from the bottom of the tray.. I get to the Hill bleed block and its dripping brake fluid. I try to tighten the lines and it drips MORE! Turns out the block had cracked along the top and bottom (smaller) faces. Tightening the lugs resulted in the aluminum cracking. So the "upgraded" hill bleed blocks aren't infallible!

    Luckily I had the old OEM bleed block that I reinstalled WITH PLUMBERS TAPE on each lug. The input lug from the line from the clutch pedal was a bit rounded as well and of course the line is NLA.. So I removed the line and freed the block from the line. Then reinstalled it to the old bleed block with 3-4 winds of plumbers tape.

    I'm argue that this should be an acceptable installation standard vs the OEM just install steel to aluminum block and tighten. With subsequent installations, you're going to get some stretch in the steel with tighter torquing down needed. Installation of the plumbers tape resulted in a tighter seal with less torque required on the pipe fittings to prevent leaks. I know some customers may balk at the thought of tape being used.. but I'm going to argue that it's an acceptable installation standard.
     
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  2. hessank

    hessank Formula 3
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    #2 hessank, May 8, 2018
    Wow, thanks for sharing. I'm a little upset because I followed the masses who continually suggest the HE replacement parts as being better and after I got my F car I couldn't wait to remove the steel block and replace it with the HE part (during a clutch job). Now I am sorry I did not keep the OE part as a spare because there was nothing wrong with it.

    Lessons learned. Again, thanks for sharing Curt
     
  3. vrsurgeon

    vrsurgeon F1 World Champ
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    #3 vrsurgeon, May 8, 2018
    Thank you for considering the post! And there's nothing wrong with the Hill block either. :) Mine lasted YEARS in the car with absolutely no issues. I just used the old to get back to driving. :) Always save your old parts! LOL :) With both just be careful how much you tighten because both can crack (apparently). My experience is the plumbers tape with installation has no negative effects, seals the threads nicely, and lowers the torque needed for a functional seal. I just want to put this here so some "I don't know bleed block from a Lego block I just write the check" owner doesn't assume that the repair was done to a lesser standard with plumbers tape.
     
  4. 24000rpm

    24000rpm F1 Rookie

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    #4 24000rpm, May 8, 2018
    I've wanted to say this for a long time:

    Is there any empirical evidence that Hill engineering parts are better than OEM?

    I couldn't find any.

    I bought a lot of Hill engineering stuff ( more than $5000) , not because they are better, but because they are cheaper.

    I never had any problem with hill engineering stuff except a tool that was broken(it might be my fault, not Hill Engineering's, but I am not sure).

    Don't get me wrong, I have nothing against the company.

    It is just that there's no evidence. If Hill reps can come out and show something, that'll be great.
     
  5. krazykarguy

    krazykarguy Formula Junior

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    #5 krazykarguy, May 8, 2018
    You need to be cautious with plumber's (teflon) tape on threaded bungs where there are dissimilar metals or fitting stretch going on. Especially so when the part being threaded into is aluminum or an other soft material.

    I ran into this regularly at a shop I used to work at. Subarus are notorious for leaking from the rear differential drain plugs after they have been drained and refilled at the 30k or 60k service. One of our techs got the smart idea to start wrapping the plugs with teflon tape (several wraps worth), and ended up cracking the several differential housings. The tolerances were so tight that the extra tape on the thread cracked them...
     
  6. timwu12

    timwu12 Formula Junior
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    #6 timwu12, May 10, 2018
    great information, Curt!

    everyone holds Hill Engineering parts on such a pedastal for being vastly superior to OEM parts so this is great to know that just slapping on a HE bleed block doesn't mean that the cracking problem will no longer be an issue.
     
  7. vrsurgeon

    vrsurgeon F1 World Champ
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    #7 vrsurgeon, May 10, 2018
    It's actually very interesting. And agreed btw.. What appears to cause the crack in the Hill piece is both the incoming line and bleed line in the block are essentially two holes drilled longitudinally through the block. Each "bung" has a wedge tapered inner end to it with threads on the outer. When you overtighten the bung, REALLY crank down on it, the wedge of the bung will act like an axe splitting a log. It forces the metal outward, which splits the block longitudinally. What I'm seeing is it requires less force to seat... and theoretically therefore less risk of cracking. The last time I used tape on the old block it lasted 5 years with no issues and no corrosion. The cracks I saw were on both ends of the spectrum BTW. Wrapped and unwrapped.
     
  8. Ferrari Tech

    Ferrari Tech Formula 3

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    #8 Ferrari Tech, May 11, 2018
    I am glad the teflon tape helped keep the fluid in. I see teflon tape on all types of fittings. The problem I have with it is when the threads are not the source of sealing. This is the case in every situation except tapered pipe thread. The clutch bleed block has, 1: conical seated tube end that provides the seal and 2: copper washer sealed bolts. Drain plugs on F cars have copper washers, (that never seal on the second use). In all of the cases I have seen teflon tape on any fitting that is not tapered, I have removed the tape and corrected whatever the issue was that prevented the proper seal of the unit. Cracked housing, bad conical seat, old copper washers, nicks and gouges on the copper washer seat surface, rust and or corrosion.
    I do understand that the need for a thread filler is helpful, I just want to remind those reading that understanding the sealing needs of the fitting and correcting the issue should not be over looked.

    Now go drive the hell out of it.
     
  9. 348paul

    348paul Formula 3

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    #9 348paul, May 12, 2018
    The clutch blocks Hill Engineering manufacture are from a far higher tensile strength aluminium than the original OEM parts and far lees susceptible to cracking. I would suggest looking at a fresh clutch pipe and see how much crush there is on the swagging in comparison to the old one that has been on car for 15+ years (or has been over tightened) - you will be very surprised. The main reason why we see any clutch block crack is the over-tightening of the union into the block due to the lack of crush left on the pipe swagging. Try putting the old pipe into a new OEM or Hill block and tighten it up on the block and you will find that the pipe will still have the ability to spin around (with a small amount of force and not seal!) This unfortunately is a classic problem of thinking that the replacement part is the problem when in-fact its the old mating part that is the culprit! (This subject is actually on our to-do list to put the pictures and information up on our new blog section on our new website.)

    Paul Hill
     

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