Dot 5 conversion

Discussion in 'The whoa and the sway.' started by David Van Horn, Apr 8, 2005.

  1. I'm restoring my '68 Wildcat so I've got the body off the frame and all the brake stuff is real accessible. So, I'm thinking of using silcone brake fluid (dot 5) because it doesn't absorb water like dot 3. Therefore, no rust in the system. Do I have to change all the rubber parts when I go to dot 5? If so, are all the dot 5 rubber parts available? TIA. :puzzled:
     
  2. GStage1

    GStage1 Always looking for parts!

    I would get new brake hoses. They are relatively cheap.
     
  3. I would change out all the rubber parts such as hoses and wheel cylinder boots (you were doing that as part of your brake job anyway, right?) when converting to DOT 5. I found this blurb at http://www.xs11.com/tips/maintenance/maint1.shtml:

    I would assume all new brake hoses and components are good for DOT3 or DOT5, just as fuel hose nowadays does not get eaten by alcohol. But, that is just an assumption. I would go to the parts counter at your favorite car parts place, ask them if the part will handle DOT5, and then get them to point that statement out to you on the manufacturer's packaging, catalog, or website.
     
  4. 1979SHX

    1979SHX derevaun seraun

    DOT 5 is good for a show car, since it's paint safe, but not good for performance. And, it still needs changed occasionally.

    The chance of internal corrosion is still there, too, just as it is with DOT 3 or 4. You'll still get moisture in the system, and it will end up in the calipers.

    Your stock pieces should be ok, but be sure to flush it thoroughly with the DOT 5 to get all of the original fluid out....master cylinder, slave cylinders, etc.
     
  5. Willy

    Willy New guy!

    Getting everything to seal up good with DOT5 is a bear, you will have leaks where you think the seal is good. Stick with 3/4 and leave 5 on the shelf.
     
  6. jamyers

    jamyers 2 gallons of fun

    I agree that DOT 5 is more trouble than it's worth. Had a '71 MGB with the stuff in it. DOT 5 will give you a slightly more "spongy" pedal feel. It won't absorb water, but any water that gets in (and some WILL...) will then migrate to the lowest point and start corroding there. I changed back to DOT4, had firmer brakes, and was a lot happier.
     
  7. nailheadina67

    nailheadina67 Official Nailheader

    I have to disagree. I switched to dot 5 and it was the best move I ever made. My wheel cylinders always seeped a little with the old stuff, but after I made the switch everything has been dry as a bone for over 3 years now. The best way to do it is to replace ALL the rubber parts, that means hoses, master cylinder and caliper and wheel cylinder seals included, with new parts. Once rubber has been exposed to dot 3 it absorbs it to a certain degree and can come back to haunt you later.

    Only thing I noticed is the silicone fluid aerates easy, so it's harder to bleed. Take your time, and once all the air is out your pedal will be just as hard as it was with the old stuff. I left mine sit overnight and bled the system by gravity the following day to make sure all the air was out. You have to leave the check valves out of the master cylinder or else gravity bleeding won't work. The reason people say it's not as good is because they don't know how to do it right. Make the switch.......you won't regret it. The fact it doesn't eat paint is the greatest part about the stuff. :bglasses:
     
  8. Iceman8.6

    Iceman8.6 Well-Known Member

    Where do you get the DOT 5 stuff at? Who makes it? I don't think I've ever seen any around here.
     
  9. GStage1

    GStage1 Always looking for parts!

    DOT 5 is silicone and you can get it at Autozone.
    You should be able to get it at any auto parts store. If not, you can get it
    from www.vettebrakes.com
     

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