Hood pops up when driving

Discussion in 'Classic Buicks' started by bhambulldog, Oct 30, 2011.

  1. bhambulldog

    bhambulldog 1955 76-RoadmasterRiviera

    Two times in the past week when I drove the Roadmaster the hood has popped open upon hitting a bump. Thankfully the safety latch prevented a disaster.
    I'm afraid to drive it more, before I can find a solution.

    Here's what I've done, am doing about it.

    I've found a used lower hood latch assembly for sale on Ebay. I have not purchased it. But, I have inquired on the price of shipping.

    I tried running the hood 'bayonet' bolt farther out.
    But, that only made the hood loose.
    So, I adjusted the bolt back up to bring the hood back down, tight.

    I've not been successful recreating the problem standing in front of the car. But, I can recreate it by driving over a bump, the hood will pop open, the safety catch is the only thing preventing it from opening completely (very unnerving!)

    I read the shop manual and today I'm going to try to adjust the lower assembly laterally, (toward the passenger side) hoping to give more surface contact between the lower latch and the upper 'bayonet' bolt
    edit: moving the latch laterally is not a solution. It only moves the hood closer to one fender. And away from the other
    Any words of wisdom, tales of experience, advice, thoughts, are most welcome.

    Thanks,
     
    Last edited: May 7, 2015
  2. dynaflow

    dynaflow shiftless...

    Think you're on right track w/lateral adj...however, another possibility is deteriorating/collapsing core support rubber mounts...allowing ft end sheet metal to move enough to trip release...:Do No:
     
  3. Smartin

    Smartin antiqueautomotiveservice.com Staff Member

    Make sure the primary latch is well lubed with something like lithium grease. It may not be engaging all the way due to corrosion or lack of lubrication.
     
  4. nineteenfifty5

    nineteenfifty5 Well-Known Member

    Bham I had the same problem my body guy was able ot fix it be adjusting the primary locking mech ,took a far bit of time but he got it. i tried to adjust it my self and ending up having the hood locked up to where i could not get it opened, that's when i took it to him for a fix.
     
  5. bhambulldog

    bhambulldog 1955 76-RoadmasterRiviera

    Thanks John
    I believe that may be the case. Each time the hood popped open it was after a hitting a hard bump. I was taking a close look at the hood bumpers just now and can see the sheet metal of the core support around the bumpers has been dimpled. After seeing that, I'm thinking issues with the fender and core mounts, just as you say. I have new hood bumpers. But, as far as I know the core mounts are 56 years old.

    I've been contemplating removing the fenders to replace the portholes, and replace the ducting, piping and heater core of the defroster. And, detail the engine properly.
    Now may be a good time to look at the Steele Rubber catalog.........

    I tried about three different positions of the upper latch bolt. Realizing that, lengthening raises the closed hood position. And, shortening lowers the closed hood position. At one trial position I removed two shims each from the four hood bumpers on the core support. But, this caused a bad looking fit between the hood and the mustache bar. Eventually, I got the closed hood to a position that looks right.

    After a couple of trial positions; I now have the lower latch assembly as far to the passenger side as the slotted holes allow.

    I'm not sure if any of this will keep the hood closed, however. I'm beginning to believe that the small spring at the rear of the lower latch is the culprit. I'm suspecting, that small spring is not creating enough tension to keep the lower latch in place when the hood is down.

    In the mean time. I'm thinking of what can I do to keep the hood down? Maybe a cable or chain with a bolt or pad lock? I mean just until I can find out what parts I need and a definite plan of action. (?)

    Thanks Adam,
    very good advice.
    I failed to list that action on this thread, as I lube the hood springs, hinges and latch regularly. We had a Super parts car that the hood folded double due to no grease. I've been a nut about keeping the hood hinges and latch greased since then.
     
  6. bhambulldog

    bhambulldog 1955 76-RoadmasterRiviera

    Thanks fifty5

    35 years Dad and I had the hood off. Getting the hood back on and adjusted was a real bear!
    We had it re-painted ten years ago. The body and paint guy fixed the hood, that time (that body shop has since closed :( ).
    For ten years, the hood been working beautifully! ........ Until two weeks ago tomorrow.

    I just came inside form monkeying around with it. I'm not sure if I've made a difference or not. When I drive it, If the hood comes up; I'll know I didn't. If, the hood does not come up while driving, I'll be wondering when it will pop up!!

    I think a good body man is what I need. This winter may be the time.......

    Right now; I'm going to eat some lunch and drink a beer.
     
  7. scott kerns

    scott kerns Silver Level contributor

    DRIVE SLOWER! :Do No: NAAH THAT CAN'T BE IT......


    Scott
     
  8. bhambulldog

    bhambulldog 1955 76-RoadmasterRiviera

    Come'on man! It's a NAILHEAD!!!
     
  9. bhambulldog

    bhambulldog 1955 76-RoadmasterRiviera

    There's an old fashioned hardware store right down in town here. I think I'll go get some newer springs to replace these on the latch assembly.
    Here's some pictures;
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  10. bhambulldog

    bhambulldog 1955 76-RoadmasterRiviera

    I've got the latch too far over! The driver's side of the hood has about a 1/4" gap. And, the passenger's side of the hood has a 1/32" gap.

    I'll get some new springs and and move it back towards the center.........
     
  11. dynaflow

    dynaflow shiftless...

    Latch springs look OK. Any wear on plunger where it contacts latch...maybe rotate plunger quarter turn or so to present new contact surface. How about contact edge of latch...worn back? Maybe tighten core support mount bolts...I'm still thinking sheet metal shake...:Do No:
     
  12. bhambulldog

    bhambulldog 1955 76-RoadmasterRiviera

    I rotated the plunger to several different positions. The latch is not worn. But, there is some play. And, there is not much resistance from the srings when pushing on the latch.
    I agree on the sheet metal shake. Last couple of times I drove it I heard some squeaking I haven't heard before...........
    I'll look at it further Saturday.
     
  13. dynaflow

    dynaflow shiftless...

    ...could be spring(s) then...hopefully you can find good replacements (tension)...
     
  14. doc

    doc Well-Known Member

    Looks like the whole shebang needs to be removed , sand blasted, and repainted, and lubed up ... then reinstalled and adjusted..... :Brow:
     
  15. Golden Oldie 65

    Golden Oldie 65 Well-Known Member

    While I'm not specifically familiar with the old Roadmaster, I don't think the springs are going to be the problem. GM designed that latch and those springs to specific specifications. Maybe it's just me but I would be leary that hardware store springs would live up to those specs. The springs don't actually hold anything as far as keeping the hood down, they only help the various moving parts on the mechanism return to their positions after performing their function. My vote goes to making sure everything is well lubed and adjusted.

    For whatever the reason the latch is not completeing it's full function when you close it. Not having it front of me makes it more difficult to figure out but I would start by removing and latch assembly, remove the springs, and make sure the latch itself is functioning properly or if it's sticking somewhere. If it is, fix it or replace it, then reinstall the springs. Next I would make sure when you close it that it does everything it's supposed to do. What I mean by that is you should hear at least a double click when it closes, one for the safety latch and one for the final position. Once you get that, adjust the hood or latch so it fits tight. Like I said, I'm not specifically familiar with the old Roadmaster but I have been around this stuff a good share of my life and always felt that a person should start a repair by having a complete understanding of how it works before starting on it, it makes the repair go a lot easier. A little tip that might help you when it comes to adjusting things..... I always use masking tape for marking. Place a piece of tape along one side of the latch so when you make an adjustment you can see how far and which direction you've moved it. I even mark centers or outside edges on the tape when adjusting doors, hoods, deck lids, etc. It goes a lot easier and you will know what works and what doesn't. It bascially takes a lot of the guess work out of it. Hope this helps.
     
  16. doc

    doc Well-Known Member

    Yep, what Bill says.....:Brow:
     
  17. bhambulldog

    bhambulldog 1955 76-RoadmasterRiviera

    Thanks everyone!

    I'm going to work on it Saturday.
     
  18. LowFlyLark

    LowFlyLark Time for a mild custom.

    Did you get it to work? I'm guessing good old fashion cleaning, some grease and a big hammer. :)
     
    Last edited: Nov 6, 2011
  19. bhambulldog

    bhambulldog 1955 76-RoadmasterRiviera

    No. I had a minor medical procedure today.
    I've looked at one on ebay. I clicked on the buy it now button. Then I get a message that my pay pal has been frozen! (?) I don't know what that's about. Looks like it will be next Saturday before I can get any thing else done on it......
    Looking around on the HAMB, AACA it seems this is a common problem for 53-56 Buicks. But, this is my first experience with it.
     
  20. kcbowden

    kcbowden kcbowden

    I had this same problem, I adjusted parts for hours, then I decided to retrieve the hood latch off a parts car I have. After comparing the two, I noticed the inside part of the lower latch was bent. I replaced latch with the one off the parts car and problem solved.
     

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