328 oil cooler hose info | FerrariChat

328 oil cooler hose info

Discussion in 'Technical Q&A' started by wolftalk, Jul 14, 2004.

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  1. wolftalk

    wolftalk Formula Junior

    Jan 27, 2004
    367
    san franciso area
    Full Name:
    phil
    long ramble follows. all you really care about is the hose size :)

    having developed a leak in the upper oil cooler line, I did what everone else did and had a good laugh over the price of a replacement. After that, I started reading, and here's what I found.

    The 328 has two different upper oil cooler lines. part number 128239 is the cheap one, and can be obtained for around $175. part # 136939 is
    twice as expensive.

    The difference is 136939 has reusable, screw-on fittings. You can simply
    unscrew the fittings and screw them onto a new hose. The cheaper
    hose has crimped on fittings. Oh, and the expensive one has a comfy
    steel braided jacket. The cheaper hose may or may not.

    my '89 uses 136939. While talking to the guys at GT car parts, I tossed
    them a measurement of the hose length. The cheaper part seems to be
    about an inch longer, which is bad news. It probably cannot be used
    to replace the expensive one.

    so I decided to try replacing the hose. I chopped the existing hose in half to measure the id/od:
    id: ~20mm
    od:~30mm

    remember, that's ths size for hose part #136939. The cheaper hose may be different

    then started looking for the hose to use with the screw-on fittings. One common supplier is aeroquip, but their hose specs are not promising. You have two choices with them...match the id, or the od, but not both.
    Their -14 hose has the right id, but od is too small. -16 has the right od, but the id is too big.

    the way the screw-on fittings work is the hose end is squashed between the ferrule and the fitting barb. As the barb screws into the ferrule, it's expanding the hose end inside the ferrule, and coarse threads on the ferrule dig into the hose jacket to hold it. If you don't have enough material sandwiched in there, the hose could pull out.

    I bought a chunk of -16 anyway to see if it would work. I wasn't happy that I could screw the banjo barb most of the way in by hand, but after it was fully seated, I tried pulling the hose to see if I could yank it off the bango. I managed to stretch the hose a bit without pulling it apart, but when I removed the banjo again, there wasn't much evidence that the ferrule was biting into the hose. Decided I didn't trust the aeroquip to hold, but I had no way to pressure test. It would be interesting to find out what would happen, especially as the oil deteriorates the hose end a little.

    Then I did what others did, when to a hydaulic shop to see what they had.
    The guy came up with Parker 421-12 hydraulic hose. id/od was
    ~19/29, so the size was right. It had an internal steel braid, and was rated for 1200 psi and 250 degrees.

    bought a chunk of that ($12) and made a hose. the banjo end went on pretty easily, the other end was harder. I wouldn't do it again...I'd let the hydraulic shop assemble the thing (if they could). I had no choice, since I cut the existing hose in half, I no longer had a reference for how to orient the ends, so I needed to be able to the fit things kinda by trial and error.

    the orientation of the ends is critical, as is the hose length. The hydraulic hose is a little less flexible that the original stuff...

    anyway, the conclusion is that if you have the screw-on fittings, you can fix the hose yourself or have a hydraulic shop do it. The trick is finding hose the right size. The shop should be able to do that, and may even find hose with an external braid rather than an internal one.

    if you have crimp on fittings, and can find a shop that can reuse/crimp the banjo end, then you have more hose options because the od doesn't matter.

    different hose manufacturers have different id/od specs. Usually the id is abou the same, but the od is often significantly different. Apparently, this forces you to use fittings from the same manufacturer :)

    I also poked around trying to figure out who made the original hose. If it was an italian company, it could have been rapisarda, diesse, or saiag.
    Rapisarda definitely did work for fiat.
    If it was saiag, then they sold out to ITR, who then decided to get out of the hose business and sold that unit to...parker.
     
  2. wolftalk

    wolftalk Formula Junior

    Jan 27, 2004
    367
    san franciso area
    Full Name:
    phil
    There's a slight (ok, catastophic) problem using hose without a braided jacket and the screw-on fittings.

    Inside the ferrule are coarse threads which mash into the hose and prevent it from sliding out. Unfortunately, these threads dig into the rubber exterior of the parker hose enough to cut down to the internal steel braid.

    The effect is like using a wire stripper. The rubber outer layer of the hose stays inside the ferrule, and the steel braided inner core slides right out. Kinda like stripping a piece of coax cable.

    The original ferrari hose has the steel braided jacket, and it prevents the slicing of the rubber. So only use hose like that.

    Frankly, I'm going to just fork out the loot for another ferrari hose. The thing takes 30 minutes to r&r, and it's not worth any more time trying to make it work. So whoever gets the next enzo off the assembly line...I paid for the oil :)

    I have the hose rebuilt with the aeroquip -16 stuff. I doubt it would hold, but if someone wants to use it as a template (what matters is the angle between the fittings, and the hose length) to find a shop that can rebuild the hoses for the next person who needs one, pm me and I'll send you the thing (along with the original ferrari hose pieces for reference).
     

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