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Heater hose fitting?

Discussion in 'Chevy Trucks' started by WOODY367, Dec 19, 2011.

  1. WOODY367

    WOODY367 Senior Member
    from LI, NY
    Messages: 467

    I have to replace the heater hose on my 99 Yukon with the 5.7L. The fatory fitting on the intake manifold is leaking. I was told that when I go to take the fitting off most of the time they break at the manifold. Any suggestion or trick befor I do this? I got a new nipple to do away with the stock setup. Can not afford to tie it up with problems. Thanks
     
  2. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,929

    Ive never had one break, just put the socket on there and wiggle back and forth a few times and they came right out. thats just me,,i have heard the same things as well.....guess i have just been lucky :)
     
  3. 2COR517

    2COR517 PlowSite Fanatic
    Messages: 7,115

    Mine broke. I used a punch and hammer and lots of patience to get the old one out. I bought two fittings, one I ground a slot into to help chase the threads. Then I glued the good one in with some Ultra Black. Still holding just fine.
     
  4. WOODY367

    WOODY367 Senior Member
    from LI, NY
    Messages: 467

    Thanks for the info. Has anyone heard that you should not use regular heater hoae as the factory hose has a restrictor in it. . if a regular hose is used the extra flow could blow out the heater core?
     
  5. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,929

    No I have never heard that hummmm tho
     
  6. 2COR517

    2COR517 PlowSite Fanatic
    Messages: 7,115

    Disregard that info. The heater core is under the same pressure regardless of flow rate.
     
  7. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Many OEM systems have a restrictor in the heater supply hose, however it isn't because of pressure, but volume. Too mulch volume through the heater core back to the "cold" side (inlet side) of the cooling system causes longer warm up times. Thus most OEM's reduced the volume to shorten the waiting period.

    On the Vortec's specifically the inlet hose intake fitting is in fact the restrictor to slow volume down and if you replace it with a generic conventional heater hose nipple you want to keep it's passage around 3/8". Most off the shelf nipples are too big so a quick hit with the welder and a redrill to a smaller size is often in order. Used to be able to purchase them based on their hole size but with a universal fit being more important for less inventory it's tough to find choices today, and therefore the needed "adjustment".
     
  8. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,929

    Wow thanks for that info B&B good to know.
     
  9. PowersTree

    PowersTree Senior Member
    Messages: 586

    B&B, your wealth of knowledge is greatly appreciated!

    I learn something new almost every time you post.

    I've always removed the failure prone stock fitting, and put a standard fitting in. Now I know why they took longer to warm up.