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How do you stop this thing!!!

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by BorregoK5, Sep 18, 2001.

  1. BorregoK5

    BorregoK5 1/2 ton status

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    Now that I've got everything running on my truck, and running well... what the heck are my options when it comes to brakes. I gotta say, standing on the pedal is getting old. I'm running a 78 K5, dana44/12b, 33's new brake pads/drum shoes and yes, just finished bleeding them. It's better, but could stand to gain a lot. Since I'm upping to a Dana60/14ff, will I have better brakes inherently from the upgrade, or perhaps should I be on the lookout for a particular Dana60/14ff which is better equipped than others?

    What, Me Worry?
    <a target="_blank" href=http://www.echobit.com:81/k5/> The 'BEFORE' pictures</a>
     
  2. Pugsley

    Pugsley 1/2 ton status

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    The 14FF will have much better drums on it, but you can't beat 4 wheel discs - convert it over, and you'll be able to stop on a dime[​IMG]

    Special thanks to those lost from IAFF Locals 94 and 854 - You shall never be forgotten
    <a target="_blank" href=http://pugsley.alloffroad.com>pugsley.alloffroad.com</a>
     
  3. BurbinOR

    BurbinOR 3/4 ton status

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    You'll stop on a dime anyway with the Dana 60 stock discs and the 14BFF stock drums. Discs are a nice thing to talk about but not needed and I read about a lot of guys on here with discs but oops, no e-brake, and problems with them locking up. Believe me, after you get the one ton conversion done, you won't believe how much better it stops than with the stock 1/2 ton stuff.

    Might want to consider power-bleeding your brakes. Made a hell of a difference with mine. Hard to get all that air out of the system when you replace everything, ya know? So take it to a 4X shop or dealership and have them do it - costs about $50-60. Worth every penny.

    <font color=blue>'79 ONE TON TPI K5 - See it at---&gt;<a target="_blank" href=http://www.blazzinor.rockcrawler.com>www.blazzinor.rockcrawler.com</a>
     
  4. TorkDSR

    TorkDSR 1/2 ton status

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    what year is the D60? they could be drums, that's the issue i'm currently dealing with. if you can't stop then replace or upgrade the master cylinder or vacuum booster. it can make a biiigggg difference, and it's easy.

    Tork DSR
    I just got a winch, it takes the fun out of things.
     
  5. BorregoK5

    BorregoK5 1/2 ton status

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    I'll try the power bleeding, that sounds reasonable. Are there any differences between the different Dana 60's or 14ff out there as far as braking capability, dual piston calipers or ???

    Is there an easy way to test a power brake master cylinder? I'm running a cam in a motor (temporarily borrowed motor) which was intended for a 68 Camaro with no power brakes, It's a 222/222 duration at 0.49 lift. Maybe the vacuum isn't strong enough to operate the power brakes using this cam. I know its doing something cause if I brake hard enough (both feet) then I can stall the engine from lack of vacuum.


    What, Me Worry?
    <a target="_blank" href=http://www.echobit.com:81/k5/> The 'BEFORE' pictures</a>
     
  6. coopertwpk

    coopertwpk 1/2 ton status

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    Make sure the rear is adjusted correctly you should have slots to see the distance the pads are away from the drum I have my wife hit the brakes adjust some more than hit them again this keeps them centered .

    88k5 silverado w4"lift <font color=orange>d44 and corp14ff</font color=orange> with 4.11
     
  7. 502Burban

    502Burban 1/2 ton status

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    If you really want an increase in stopping power, especially if you're having low vacuum problems due to the cam, switch to a HydroBoost power brake booster. You won't believe the difference.

    Just my .02,

    Robb
    '73 GMC Suburban - 502DFI
    <a target="_blank" href=http://community.webshots.com/user/robbrj>community.webshots.com/user/robbrj</a>
     
  8. BorregoK5

    BorregoK5 1/2 ton status

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    I like the HydroBoost option, thank you. From what I can find, I might be able to pull one from a cadillac out of a local junk yard. Do you know of any direct bolt ins, or will I be fabricating a mounting bracket? What are the cons here, nothing comes without a price.

    Link for otheres to reference: The 'BEFORE' pictures
    <P ID="edit"><FONT class="small">Edited by BorregoK5 on 09/18/01 11:09 PM.</FONT></P>
     
  9. 502Burban

    502Burban 1/2 ton status

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    Borrego,

    Here's a <a target="_blank" href=http://coloradok5.com/forums/showthreaded.php?Cat=&amp;Board=blazer4x4&amp;Number=195067&amp;Search=true&amp;Forum=All_Forums&amp;Words=502Burban&amp;Match=Username&amp;Searchpage=1&amp;Limit=25&amp;Old=allposts&amp;Main=194988>link to a previous post</a> I made regarding a swap to HydroBoost system. Just about any diesel GM truck will make a good donor vehicle. 1-ton trucks also seem to frequently come with HydroBoost. Let me know if you have any questions that aren't answered there.



    Robb
    '73 GMC Suburban - 502DFI
    <a target="_blank" href=http://community.webshots.com/user/robbrj>community.webshots.com/user/robbrj</a>
     
  10. ftn96

    ftn96 1/2 ton status

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    I'd be willing to bet that the rear shoes need to be adjusted out a little bit more. My pedal was going all the way to the floor with hours of bleeding and everythifn was new. I had already adjusted the shoes out till they were rubing but after a few miles I found that I had burned of the high spot and now they were not rubbing any more. So I re-adjusted them till they were barely rubbing again and WO!!!!! They only move an inch or 2 and....
    Anyways I can now stop on a dime and leave 9 cents change.

    "you know... the guy with the BAD A$$ spring perches!!![​IMG]
    <a target="_blank" href=http://www.nashvillek5.freeservers.com>www.nashvillek5.freeservers.com</a>
     
  11. BorregoK5

    BorregoK5 1/2 ton status

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    I wish that was the case for me. I never reach the floor on my brake pedal, in fact, I rarely get past the half way mark unless I'm standing both feet on the pedal HARD... which won't lock em up but at least comes to a fairly good stop.

    Thanks for the link 502Burban, I think this is the route I'm going.

    What, Me Worry?
    <a target="_blank" href=http://www.echobit.com:81/k5/> The 'BEFORE' pictures</a>
     
  12. BorregoK5

    BorregoK5 1/2 ton status

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    Well, I've narrowed down my current brake problem to be directly associated to vacuum!!! I found that if I go directly from the gas pedal to the brake without hesitation, I have to stand both feet on it to stop at all... but if I wait about 3 seconds then my brakes work just fine, unless I pump them, then its stand on them all over again. This returns me to suspecting the cam as the vacuum killing culprit. Anyone running an extreme cam out there that might be able to validate this or might I have a bad brake booster. In all honesty, I'm going with a hydroboost to solve this, but my curiosity wont let me let this go till I definitively figure out what my issue is!!!

    What, Me Worry?
    <a target="_blank" href=http://www.echobit.com:81/k5/> The 'BEFORE' pictures</a>
     
  13. Blazer83

    Blazer83 Registered Member

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    I just had a similar problem with my S10 Blazer. Booster started to go and then just totally went south. Pedal is extremely hard, worse than no power brakes. Having driven Military vehicles made in the 50's, I know what hard brakes feel like. This was unreal. Down in Galveston on vacation is not the place to be when you have to make repairs. If you have good vacuum going to the booster, probably is your booster that has gone south. Do you hear any type of air rushing in under the dash when you step on the pedal?
     
  14. BorregoK5

    BorregoK5 1/2 ton status

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    No hissing, unfortunately I'm grabbing at straws here. I should probably check manifold vacuum after I stab the throttle, with the booster connected and disconnected to see how quickly it recovers to 15psi. I wish I had a vacuum pump to hook up to the booster and check that... trying to think of other ways to check it.

    What, Me Worry?
    <a target="_blank" href=http://www.echobit.com:81/k5/> The 'BEFORE' pictures</a>
     
  15. ftn96

    ftn96 1/2 ton status

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    Yes Sir! That will damn sure kill your vacum running a over kill cam. My uncle build a corvette motor for a guy oonce and it had some cam like .445 lift @ .50 on the exhuast or something. Damn thing wouldn't even idle let alone that the brakes wouldn't work at all. But thats what cam the guy wanted and thats what he got.

    "you know... the guy with the BAD A$$ spring perches!!![​IMG]
    <a target="_blank" href=http://www.nashvillek5.freeservers.com>www.nashvillek5.freeservers.com</a>
     
  16. ftn96

    ftn96 1/2 ton status

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    You could always incorp a parachute.LOL!!![​IMG]

    "you know... the guy with the BAD A$$ spring perches!!![​IMG]
    <a target="_blank" href=http://www.nashvillek5.freeservers.com>www.nashvillek5.freeservers.com</a>
     
  17. dyeager535

    dyeager535 1 ton status Premium Member

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    Have you checked the check valve on the booster to carb/intake line to make sure its good? Not sure if that could cause this, but its an easy check.

    Booster check is to turn vehicle on, let vehicle idle for a few seconds, without touching brake pedal. Turn it off, wait 45 minutes or so, then try brake pedal without starting truck. Should have 2-3 power assists left.

    Be advised that bleeding an old master cylinder can easily lead to failure. When you bleed, the pedal and MC piston, travel further than they have, likely since new, or at least last time the brakes were worked on. That exposes the MC piston seals to built up crud and corrosion, which causes them to then leak.

    I bled a perfectly good MC on my truck, and never could get rid of the "spongy" pedal feel. When later, the pedal slowly went to the floor at a light, I figured it was time to replace the MC.

    Dorian

    Dorian
    My tech/links page: <a target="_blank" href=http://www.dorianyeager.com/index2.html>http://www.dorianyeager.com/index2.html</a>
    No anti-theft measures on your truck? No pity when its stolen
     
  18. BorregoK5

    BorregoK5 1/2 ton status

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    Yeah, I wasn't sure about the check valve, I'm going to go give that a test.

    Definately not spongy though, and never hits the floor... I'm going to have to go pick up a vacuum pump and see if the vacuum assist is leaking or ???

    What, Me Worry?
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  19. 502Burban

    502Burban 1/2 ton status

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    I know that you are probably going with the HydroBoost conversion, but if low vacuum signal from the larger overlap cam is your only problem, there is a less expensive fix.

    In street cars with hyperactive cam profiles, it is common to run a vacuum reservoir to combat this problem. Summit sells some that you can see community.webshots.com/user/robbrj
     
  20. BorregoK5

    BorregoK5 1/2 ton status

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    Well, I've finally tracked down the brake problem! After replacing the shoes and pads, checking all the lines for leaks and blockage, bleeding the system (many times), verifying that the check valve and filter were in good shape and finally making sure I had 'enough' vacuum (17 in) I was down to the power brake booster as Blazer83 pointed out. I ran the test like you suggested dyeager535 and I could still get a few good pumps on the pedal after shutdown before it went rock hard again. I started the engine again, shut it down,waited about an hour and came back to check the 'check valve' and upon removal heard a rush of air enter the booster, that verified it was holding vacuum and I just about threw in the towel. Luckily, a buddy had called me up and had me try one final test which finally pinpointed the booster so I wanted to share it and finally close this thread. You release any vacuum from the booster by purging it at the check valve, then hook it all back up, push the brake to the floor firmly and start the engine. The brake pedal was supposed to sink a little bit as the vaccum built up( a few seconds) but lo and behold, nothing! Over about 5 minutes it slowly sank about 1/2 inch. I CAN FINALLY SLEEP! ... and of course , go buy a hydroboost and forget this ever happened.

    What, Me Worry?
    <a target="_blank" href=http://www.echobit.com:81/k5/> The 'BEFORE' pictures</a>
     

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