Real time rear heater bypass question

Discussion in '80-Series Tech' started by Anvil, Apr 16, 2018.

  1. Anvil

    Anvil

    Messages:
    667
    Likes Received:
    171
    Joined:
    Apr 9, 2009
    Location:
    Lafayette, Louisiana (temporary)
    I had coolant leaking from the rear heater coolant lines behind the heat shield. I decided to bypass the rear heater for now. The picture below is what I currently have. (I know, I need Gates Green Stripe but this is the only heater hose the parts store had.)

    It's been 5 days and I still have coolants leaking from the shield area and the reservoir (new) level continues to drop. Question... Did I miss something when bypassing the rear heater?

    Also, two weeks ago I replaced all coolant components and cannot find a leak anywhere. I'm taking the 80 on a long trip in the morning and need to fix this today.

    Any help/advice is much appreciated! Thanks!!

    20180416_115312.jpg
     
  2. BILT4ME

    BILT4ME

    Messages:
    5,578
    Media:
    3
    Albums:
    2
    Likes Received:
    6,901
    Joined:
    Nov 9, 2012
    Location:
    Olathe, KS, USA
    The only other possibilities are the other hoses, the main heater core, or the head gasket.

    Check your PHH. It may be dripping someplace that it's blowing off before it hits the floor.

    Pressure test your cooling system with a pressure setup from a FLAPS (Friendly Local Auto Parts Store). If that has no results, then get the exhaust gases test kit and check your radiator for exhaust gases.
     
  3. Anvil

    Anvil

    Messages:
    667
    Likes Received:
    171
    Joined:
    Apr 9, 2009
    Location:
    Lafayette, Louisiana (temporary)
    Thanks Bilt4me! The PHH has recently been changed to silicone.

    Yikes! I didn't think about a head gasket... :eek:
     
  4. jeeprjames

    jeeprjames

    Messages:
    70
    Media:
    1
    Albums:
    1
    Likes Received:
    46
    Joined:
    Aug 7, 2013
    Location:
    Hanahan, SC
    The coolant underneath could be what was left in the lines after you bypassed the rear heater.
     
  5. Anvil

    Anvil

    Messages:
    667
    Likes Received:
    171
    Joined:
    Apr 9, 2009
    Location:
    Lafayette, Louisiana (temporary)
    Thanks what I'm hoping is the cause. The puddles are getting smaller... but it's sure taking a long time.
     
  6. jeeprjames

    jeeprjames

    Messages:
    70
    Media:
    1
    Albums:
    1
    Likes Received:
    46
    Joined:
    Aug 7, 2013
    Location:
    Hanahan, SC
    Crawl under and cut the rubber hoses or remove them completely to expedite the process!
     
    Marine7 likes this.
  7. bigredmachine

    bigredmachine

    Messages:
    1,297
    Likes Received:
    397
    Joined:
    Aug 22, 2010
    Location:
    Jersey, 07740
    probably not, if you looped out both sides than your good to go.

    you would be surprised how long those lines can leak, after I looped mine out it leaked for another day or so. threes a lot more coolant than you would expect in the rear heater core. also you may get a leak father down the road from where the line will inevitably rust out again, that happen to me about 8 months after I looped out the rear heat
     
  8. madisonr34

    madisonr34

    Messages:
    329
    Likes Received:
    119
    Joined:
    Jun 3, 2015
    That heater hose u have is incredibly hard to use cause that hard red shell makes the rubber hard to fit over and seal the fittings.

    Get some softer green stripe rubber heater hose and use that. Do you still have the factory 5/8 spring clamps left over from the bypass?? If you do, use those clamps over the screw type.

    Also there is still alot of coolant left in the rear heater core after the bypass. It won't drain out as the lines sit above the rear heater core. Are you planning on keeping the rear heater? If not just snip the lines from the bottom or rip the core out from under the passenger seat.
     
  9. Anvil

    Anvil

    Messages:
    667
    Likes Received:
    171
    Joined:
    Apr 9, 2009
    Location:
    Lafayette, Louisiana (temporary)
    Thanks guys! I think the other part of the problem is my ignorance. I did not know how much the coolant reservoir fluctuates! Depending on when I check the capacity... it can vary 1/2"-3/4" from the fill mark. I still don't understand this. :hmm:

    The leak has finally reduced to a few drops.

    Thanks again!!
     
  10. Desert Dino

    Desert Dino

    Messages:
    704
    Likes Received:
    1,079
    Joined:
    Jul 5, 2017
    Location:
    Israel
    PHH is the only pipe that should not be done with silicone

    OEM works for 20 years or Gates green stripe will work until only cuckroachs will be left on earth
     
  11. Rifleman

    Rifleman

    Messages:
    1,402
    Likes Received:
    885
    Joined:
    Feb 4, 2015
    Anvil, when you replaced your PHH hose did you happen to check out the condition of the throttle body water bypass coolant hose number 1, and number 2? Bypass hose number 1 is not alot of fun to replace, but both can be a source of leaks.
     
  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.