Access to brake lines at inside mounting point? 308 | FerrariChat

Access to brake lines at inside mounting point? 308

Discussion in 'Technical Q&A' started by Mike328, Jan 7, 2004.

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  1. Mike328

    Mike328 F1 Rookie
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    Oct 19, 2002
    2,655
    Boulder, CO
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    Mike
    I'm working on replacing the brake lines in my 1978 308 (US Spec).

    Each of the four hoses is mounted at either end by two similar assemblies (nut around the outside of the brake line fitting, hydraulic hard line inserted into the same brake line fitting, which is threaded both internally and externally.

    I've managed to get things undone on the "outside" connection--closest to the tires--of the front and rear lines.

    Trouble is, I'm at a loss to see how things get disconnected at the INSIDE mounting point. There's virtually no clearance for any kind of a wrench. Suspension parts and A-arms appear to be in the way. Access from below may be a bit better (requires removal of underside access panels, I think).

    Anybody have any ideas in this regard on how to get to the inside mountings?
     
  2. Mike328

    Mike328 F1 Rookie
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    OK. I got them off. I better get down what I did for the benefit of others who might try this pain in the ass job.

    I did the rear left and the front left. I'm assuming the rights should be identical.

    FRONT:
    Inner Mounting
    NOTE: I had to cut this line to get it off
    NOTE: This assumes you have the outer mounting already apart.

    1. Lube everything up ridiculously with penetrant. Wait. Do it again. Wait. Do it again. Preferably overnight, though I did it in one night.

    2. There's very little clearance for any kind of wrench here. There are two nuts we're concerned with. First is the 11mm hard brake line nut that fits into the flexible brake line we're installing. Second is the 17mm nut/fitting on the actual flexible brake line itself that fits into the mounting. I tried a 17mm stub wrench on the brake line fitting but couldn't crack it. This is where I decided to cut the hose to get it off, allowing for a socket.

    3. Cut the hose as close as possible to the 17mm fitting near the inner mount for the flexible brake line. This should be short enough to allow a deep socket to fit over it.

    4. Now get your 17mm deep socket. I used a Craftsman 3/8" 17mm deep socket with a standard craftsman 3/8" ratchet drive.

    5. Loosen the 17mm nut / hex fitting at the inside mount. The flexible brake line will turn as you do this, since they're attached. You only want to loosen this enough to CRACK it.

    6. The big problem is that the 11mm hard brake line nut at the inside mount will be stuck in the now cut brake line's inner hex fitting. Unfortunately there's not enough room to loosen this, not that I found anyway.

    7. So the idea is that we would use our deep socket and ratchet drive to loosen the 17mm hex fitting. Ideally, it would unscrew itself from the 11mm hard line nut part. Since they're stuck, you'll just end up twisting this. Note that the hard line itself started to bend a bit.

    8. Yikes! This is where I immediately stopped. I was able to put a 11mm open ended wrench (flare wrench wouldn't get on!) by "feeling" onto the 11mm hard line nut part to hold it firm while I turned the deep socket on the other side. Note that you may have to do some preliminary turning with the deep socket to be able to get an angle on the 11mm nut (there's < 60 degrees clearance for it). Note that I was able to hold the 11mm nut fixed with the wrench, with the wrench extending out towards the front of the car.

    9. With the 11mm nut fixed, I was now able to rotate counterclockwise (loosen!) the short part of the brake line via the 17mm deep socket/ratchet. Loosen it all the way. You'll have to manually unscrew the 11mm nut and/or continue to hold it steady with the wrench as you unscrew the now cut brake line.

    10. The 23/24mm nut on the other side should be able to be easily removed. I had to hold this and the middle mouting "plate" steady with my hand as a I further loosened with socket.

    11. Voila! The inside brake line is now removed. I wish I knew how to do this without cutting the line, but I really do suspect that it may not be possible.
     
  3. Mike328

    Mike328 F1 Rookie
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    REAR:
    Inner Mounting
    NOTE: I did NOT have to cut this line to get it off.
    NOTE: This assumes you have the outer mounting already apart.

    1. As above, spray penetrant liberally (don't get this in the brake lines, by the way).

    2. Here we're fortunate to have a little extra room to work with with a wrench.

    3. I used an 11mm flare wrench to attach loosen the 11mm hard brake line nut that goes into the flexible brake line we're trying to remove. I was able to "crack" it and then loosen it quite a bit.

    4. I took the box end of a 17mm stubby wrench and threaded it over the now unattached free outside end of the flexible brake line. I placed it over the 17mm hex fitting at the inside mount of the flexible brake line we're trying to remove.

    5. This is what I loosened the line with. Note that I did this with the 11mm hard line nut part already loose. In this manner, I "unscrewed" the brake line from its inner mount with the 17mm stubby. Since the 11mm hard line nute part was loose it just "unscrewed" itself over that fitting. Towards the very end I actually ended up twisting the brake line itself to finally get it off all the way.

    6. Voila! One removed rear brake line, intact.

    NOTE: For the inner mounts I believe I had to bend the part of the "safety" tab outwards, referring to the flat metal part that points towards the outside of the car at you when working on it. I bent it downwards to be able to get a wrench/socket on it. I did not have to bend the one little "tab" on that same safety bracket which points towards the inside of the car away from you (the worker) and covering the 23mm/24mm hex nut.
     
  4. Mike328

    Mike328 F1 Rookie
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    OUTSIDE MOUNTS
    NOTE: These are easier than the inside mounts :)

    In all cases,

    1. Make sure everything is sprayed well with penetrant.
    2. Make sure the hydraulic hard line has been broken "loose" out of the brake line and can begin to rotate out (counterclockwise) of the brake line. Use an 11mm flare wrench to do this.
    3. Bend back both little tabs on the safety bracket just enough to allow the 23/24mm nut to turn.

    FRONT OUTSIDE MOUNT
    1. You can try to loosen the 17mm brake line hex fitting at the outside mount. I was unable to get this cracked. So, I focused on the 23/24mm nut.
    2. Loosen the large 23/24mm nut that goes around the outside brake line fitting which attaches the brake line to the actual bracket. Use a medium/large open-ended adjustable wrench for this. You'll really have to make sure those metal tabs are out of the way to be able to get the wrench on them. You want to "crack" this nut and then just remove it by hand. Voila, free outside end of the front flexible brake hose. Keep track of the safety bracket and large nut.

    REAR OUTSIDE MOUNT
    1. Loosen the 17mm brake line hex fitting with a flare wrench, just enough to "crack" it. Everything should now be loose, including the 23/24mm large nut. You can now loosen this large nut by hand, and everything comes apart nicely. Voila. free outside end of the rear flexible brake hose. Don't loose the bracket or the nut!

    NOTE: NOWHERE on these lines and mounting assemblies did I identify the presence of a SINGLE washer.
     
  5. Mike328

    Mike328 F1 Rookie
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    Here's a final revised Word Document I prepared that records this information.
     
  6. Russ Gould

    Russ Gould Formula 3

    Nov 8, 2004
    1,073
    I spent most of an afternoon trying to install braided flex front brake lines on my 308. The inner mounting is exceedingly difficult to work as you pointed out. There is not enough slack in the hard brake line to pull the junction through the hole in the mounting plate after removing the clip. But it can be done without cutting the hose, 1/16 of a turn at a time, using a SHORT 11mm (or 3/8") box wrench on the inner part and a LONG 17mm box wrench (or 7/16") on the outer part. This can be done with the suspension intact but it's a bit easier with it removed. You access the inner nut from the nose end of the car, that wrench just holds the junction so all you have to do is get it onto the nut. You undo the outer (after removing the hose from the junction nearer to the caliper) with the long wrench from behind the shock, ie from the rear. You just need to get it to move and then you can unscrew the hose easily. Reinstall is worse, you have to get under the car and manipulate the short 11mm wrench a ridiculous number of times, or at least I had to. I have to believe the factory installs this brake hose before installing the tub for the spare wheel. You will cuss more in one afternoon trying to get this done than you normally cuss in about a month. This is by far the trickiest nut I have ever had to wrench on, worse than trying to remove the oil filter pedestal on one of these cars without disassembling the fuel plumbing.

    I think a short 11mm crow's foot wrench might make it easier but I didn't try that as I don't have one. You could maybe access the inner nut through the hole in the chassis just above it.
     

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