Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

Rear disk brakes-how much more power?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by 84k5, Oct 29, 2001.

  1. 84k5

    84k5 1/2 ton status

    Joined:
    May 13, 2000
    Posts:
    2,949
    Likes Received:
    0
    Location:
    Dublin, CA
    I was wondering if anyone had done some before and after testing. The before being with the stock drums and the after with rear disk. I am wondering how much quicker you could stop? Seems like bigger front brakes would help more than rear disk, since the rears just lock up when you stomp on the brake pedal.

    Brian
     
  2. dysphemism

    dysphemism 1/2 ton status

    Joined:
    Oct 26, 2001
    Posts:
    667
    Likes Received:
    0
    Location:
    Fremont, CA
    4wheel and offroad did a test on their 79 Chevy to find that the discs stopped about 10 feet sooner than the drums did
     
  3. Leadfoot

    Leadfoot 1/2 ton status Premium Member

    Joined:
    Nov 28, 2000
    Posts:
    3,112
    Likes Received:
    1
    Location:
    Western Massachusetts
    If the rears do lock up, you are correct, they will not help you stop quicker. In most cases (that I have heard) rear discs do not lock up too quickly even with stock prop valve unless your rear-end is real light [​IMG]. If it becomes a problem then just put in an adjustable prop valve to adjust bias. The drawback of going bigger front brakes is of course wheel size and if you have a heavy load or trailer and you hit the brakes while cornering, you have a good chance of jacknifing it. You are usually better off with four good brakes than two great brakes and two half assed. The newer cars and trucks now bias diagonally instead of front to back (some do both) to help out in cornering situations and makes it safer for towing/hauling heavy loads. Hope this helps.

    See my rig at <a target="_blank" href=http://coloradok5.com/gallery/Leadfoot>http://coloradok5.com/gallery/Leadfoot</a>
     
  4. Blue85

    Blue85 Troll Premium Member

    Joined:
    Jul 26, 2000
    Posts:
    9,073
    Likes Received:
    485
    Location:
    Grand Rapids area
    The rears shouldn't lock up first. However, when you lift a truck, the weight bias moves further forward during braking since the center of gravity is raised. Sometimes bigger brakes help prevent locking since they give more consistent, controlled force. A drum brake gives more braking force for the same applied force, which is part of why the rear doesn't lock up anymore when people go rear disk with the stock prop valve and master cylinder. A disk will need more pressure and more fluid volume.

    <font color=green>There's nothing like the smell of a rich V-8 in the morning...</font color=green>
     
  5. blazbrnc

    blazbrnc 1/2 ton status

    Joined:
    Mar 16, 2001
    Posts:
    181
    Likes Received:
    0
    Location:
    southern MI
    To answer the question, I noticed a big difference between half ton discs/drums and 3/4 ton discs/discs. I never measured the differences, but it was definately a change for the better. Stock prop valve also.

    '79 K5, '79 Suburban, '76 Br**co, 77 K20
    '99 BB 4x4 Suburban to tow more junk home
     

Share This Page