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Technical 1961 Olds 88 dual master cylinder conversion??

Discussion in 'The Hokey Ass Message Board' started by jakespeed63, Jun 8, 2015.

  1. Trying to help a friend, with his 1961 Olds Super 88 Bubbletop. Sweet original survivor , but he wants the peace of mind with dual master and front discs. Was able to get the front disc conversion, with help from Scarebird. https://scarebird.com/index.php?route=product/product&product_id=111
    But needs to swap out the single master and maybe booster, for a dual/disc model. Anyone done this or know of supplier, whom offers the parts??
    Thanks,
    JT
    1961 Olds Super 88.jpg
     
    Last edited: Jul 8, 2015
  2. oldrelics
    Joined: Apr 7, 2008
    Posts: 1,727

    oldrelics
    Member
    from Calgary

    I'm looking for the same answer for my 61. The olds has the common 3 3/4"? four bolt booster mounting pattern so an aftermarket combo should be a fairly easy swap.
    Mine has an unknown mopar ( I think) dual master with and aftermarket booster. Great braking power even with drums up front, in fact it almost has too much braking power.
    I am looking to replace it with a new combo sometime soon.
     
  3. Mr48chev
    Joined: Dec 28, 2007
    Posts: 30,185

    Mr48chev
    Member

    Well a direct master cylinder swap is probably out do to the original one having four bolts.
    From whoat Oldrelics said above I'd think that he might find a mid 70's master cylinder/booster combo that would be pretty much a bolt in.
     
  4. oldrelics
    Joined: Apr 7, 2008
    Posts: 1,727

    oldrelics
    Member
    from Calgary

    The booster to firewall is the 4 bolt pattern, not master to booster....
     

  5. gimpyshotrods likes this.
  6. Inline Tube has a vast amount of good shit, hope it works out. Both my '62 and '64 Olds had great stopping with the power brakes and drums. If I had another one, I'd stay drums and just change to a dual master.
     
    gimpyshotrods likes this.
  7. Lucked out, on my '64 98 project. Was able to swap out a '66 Cadillac dual master cylinder, for the factory single master. (also keeping drums all the way around) Was actually a piece of cake. Even re-used the 4 way brass junction block. Just relocated it up towards the 2 front brake lines and blocked off the large port with a flare plug. of course, other port went up to the master.
    Still need to replace wheel cylinders and hoses, so do not have definitive test results yet. See no reason, why it shouldn't work.
    JT
     
  8. Been diving into this brake upgrade project. Will definitely require some modifications, but none too drastic, to make the swap impossible. First and foremost, the booster push-rod is too long and needs an eyelet, on the end. So, cutting it down to 3 1/2" (from booster face) and having it tig welded with the eyelet from the old brake booster. I think I am going to trim that round tube about 3/8" as well. Worried about the brake pedal travel being limited. I also had to slightly elongate the 4 holes, in firewall plate. Centerline on new booster mounting studs is smaller by about 1/8"-3/16"

    Other fun will include drilling holes in driver's fenderwell, to allow lines to exit master cylinder. Clearance is very close. Tried getting a master, with outlet, on the right side, but those are only for 4 wheel disc applications.
    1961 Olds Super 88.jpg
    DSCN6730.JPG DSCN6730.JPG
    "kit" supplied from Inline Tube Company.

    DSCN6731.JPG
    DSCN6732.JPG
    DSCN6733.JPG
     
    Last edited: Jul 8, 2015
  9. Cut down the push rod, to duplicate the 3 1/2" of the original. Cut eyelet from old booster. Also had to trim the Delron collar .750" there is a thin inner metal collar, that will come out. Trimmed that one about .675"
    Dropped it off at Badger Welding, for Jose' to work his tig welding magic. Was worried about transferring too much heat to the rubber bellows.
    JT
    1961 Olds Super 88 2.jpg 1961 Olds Super 88 1.jpg

     
  10. Sliced my leg open, at work last week, so out of commission, till later next week. In the mean time, thought I would share a few more pics I snapped. Love this body style.
    DSCN6746.JPG DSCN6741.JPG
     

    Attached Files:

  11. papajohn
    Joined: Nov 2, 2006
    Posts: 892

    papajohn
    Member

  12. Well, the new dual outlet master arrived today, from Speedy Bill. Also the 10lb residual check valve. So glad it came with the small bushing, for the push rod. Would have had to make one. Secured it with a dab of silicone, just to make sure it would not get lost.
    Now i have to fab a small bracket to support the P-valve, under the master. Also need to source out a few reducing adapters, for the P-valve, as the two inlet ports are 7/16-24 and 1/2-20 respectively. Master cylinder outlets are both std. 3/16" tube fittings(3/8-24 thread??) Hoping NAPA can hook me up. Hate to have to wait, for an online co. to ship them.
    DSCN6750.JPG DSCN6752.JPG DSCN6753.JPG DSCN6754.JPG
     

    Attached Files:

  13. Kinda tight quarters, on this body style. May not have the room to get fancy, with all the lines, like I did on my '64 Olds 98. :cool: At least I am not having to go through the damn fendewell, like with the original m/c, from Inline Tube. Very surprised, they do not sell this dual outlet version. :confused:o_O
    DSCN6724.JPG DSCN6725.JPG DSCN6727.JPG DSCN6728.JPG
     
  14. BuckeyeBuicks
    Joined: Jan 4, 2010
    Posts: 2,430

    BuckeyeBuicks
    Member
    from ohio

    That Olds is slicker than a minies dick!!
     
    jakespeed63 likes this.
  15. Attempting to take full advantage, of being out of work, from an injury. Did a little fab work today. Found the correct brake lines, I needed, at NAPA. Had to shorten both lines about an inch and re-flare. So grabbed a piece of scrap, from my buddy's shop and made a bracket, similar to the ones I have seen from Inline Tube. Ready to bench bleed and hang on the booster and finish plumbing.
    JT
    BTW.. that is a 30 degree bend, on that bracket. :)...found out the hard way. ;)
    1961 Oldsmobile 007.JPG 1961 Oldsmobile 008.JPG 1961 Oldsmobile 009.JPG 1961 Oldsmobile 010.JPG 1961 Oldsmobile 011.JPG

     
  16. Hey Fellas, Time to put the wraps on this project. Sunday morning was the perfect time to finalize all the details. Had to fabricate a few more fancy lines. Did my best to replicate what GM would have done. (wwgmd) :p
    Flushed the system with fresh DOT3 fluid, then did a thorough leak test, at ALL my fittings. Found a few small leaks. I find it best to snug the lines, then back off, then snug again. Seems to help seat the flares. Had the owner push hard on the pedal, as I tested each connection. Safety First!!
    So...pedal travel and assist pressure were both spot-on! Performed a couple of practice stops, up and down the driveway, before proceeding out on to public roads. Stops better than ever. Drove out on the street and did a few mild stops, then 3 heavy panic stops.....arrow straight and hauls this 2 ton sled to a halt in no time flat!
    Best part...owner is Super(88) happy) ;)
    Feel free to PM me for anymore detail
    JT
    GetAttachment.jpg
    You've heard of bench bleeding, well this is tailgate bleeding. ha:)
    GetAttachment (1).jpg
    The power of caffeine :p
    GetAttachment (2).jpg
     
  17. You sir have my respect. Done a fine job there.
     
    jakespeed63 likes this.
  18. JimmyG, Thanks for the kind words, along with all the rest of you. there is a thread on the Hamb, with a guy rebuilding his '55 Chevy wagon. Truly the insperation behind my attention to detail and posting all these pics. Did not have my camera with me Sunday, so had to take pictures, with my little flip cell phone. Will try and get a few better ones this week.
    Overall this car drives like a dream...except for one thing. She REALLY needs that Ross Racing 700R4 trans conversion kit. Slim Jim's suck.
    JT
     
    Last edited: Aug 24, 2015
  19. oldrelics
    Joined: Apr 7, 2008
    Posts: 1,727

    oldrelics
    Member
    from Calgary

    Very neat, thanks, if or when I could afford to do mine.....
    I agree with the slim jim comment, I replaced mine with a th350 and never looked back.
     
  20. KQQLCAT
    Joined: Nov 1, 2007
    Posts: 72

    KQQLCAT
    Member
    from Hudson, WI

    This is what I did on my 61.
     

    Attached Files:

    jakespeed63 and papajohn like this.
  21. oldrelics
    Joined: Apr 7, 2008
    Posts: 1,727

    oldrelics
    Member
    from Calgary

    What kind of booster/master did you use? Do you have front discs?
     
  22. KQQLCAT
    Joined: Nov 1, 2007
    Posts: 72

    KQQLCAT
    Member
    from Hudson, WI

    I bought a booster for a 68-70 Olds 98 A1 Cardone #54-73115, its a dual diaphram style to give enough boost to operate the front discs from scarebird I installed. The brakes work as well as my new car. Ihe master is just a after market corvette style.
    Pat
     
  23. KQQCAT, How did you address the differerence in push rod style and length? Or was it the same?? Also, all the Vette masters I looked at, had the outlet ports on the fenderwell side. From the picture, it looks as if yours exited engine side.
    Spoke with the '61 owner yesterday, he said the car is working great. Makes me so happy.:)
    JT
     
  24. KQQLCAT
    Joined: Nov 1, 2007
    Posts: 72

    KQQLCAT
    Member
    from Hudson, WI

    My master came with an adapter for the two lengths. This is the one I ordered from ebay and the lines can go on either side.
    [​IMG]
     
  25. Well, as a result of the work I did on this Olds AND some good tech tips, from my buddy Don Moyer, now I get to sort out the 4 wheel disc system, on my good friend Pauly's '37 Studebaker Custom.
    I need to do a seperate thread, on ALL the custom features, he did to this Hot Rod. Yes, the MB headlights are dated, but the rest of the car makes up for it.

    JT IMG_1604[1].JPG
     

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