Results 1 to 4 of 4

Thread: '01 LB7 Leaking coolant through breather hose

  1. #1

    Question '01 LB7 Leaking coolant through breather hose

    Has anyone noticed coolant coming out the breather hose which extends from the top of the engine down the right side? I can't seem to find this hose on either of my other two dmax's. Water pump and t-stats were changed last fall. Coolant leak began earlier this summer and is progressively getting worse. Truck has 97,000 mi on it. Any advise would be great.
    01 Chevy 3500 Pickup
    05 Chevy 4500 Dump Body
    06 Chevy 3500 Service Body

  2. #2
    Join Date
    Apr 2001
    Location
    CA
    Posts
    13,639

    Arrow

    Welcome aboard, Ben!

    Breather hose??? There are only 2 of these on an '01 Duramax, and neither have anything to do with coolant. The location you describe might be the turbo coolant return line. When they leak, it's usually the rubber hose connection behind the fan pulley. Although, it could be chafed or otherwise failed anywhere between the stat housing and the turbo. The "breather hose" at the front/right of the engine that extends down is the crankcase breather. If you have coolant coming out of that one, hoo-boy! If you are referring to the air intake breather, same thing....Hoo-boy. Coolant doesn't belong there, either. The only other place you might have coolant on that side of the engine could be the coolant storage tank, or its hoses. It has a breather, but it is attached to the tank, not the engine. If you are puking coolant from there, you have coolant system pressurization issues (most often head gasket).
    1985 Blazer 6.2
    2001 GMC 2500HD D/A
    dmaxmaverick@thedieselpage.com

  3. #3

    Arrow

    Thanks for the reply. I would think this would be the crankcase breather. It originates from both sides of the engine, tees, flows though a small tank of some kind, and then down around the transmission cooler lines. It is definately not coming from the overflow hose on the coolant resevoir. I suppose I should say that I have not actually seen the coolant flowing from this breather hose, but the location of the puddle and gunk around the end of it led me to think this is the point of origin. I'll do some further investigation. Is it possible for coolant to puke out this hose? There are no visible signs of coolant in the oil. Oil level is consistent.
    01 Chevy 3500 Pickup
    05 Chevy 4500 Dump Body
    06 Chevy 3500 Service Body

  4. #4
    Join Date
    Apr 2001
    Location
    CA
    Posts
    13,639

    Arrow

    The coolant can't leak out the crankcase vent pipe unless something is REALLY wrong. You'd know it, without a doubt.


    You'll have to find the origin. Start by looking at the turbo coolant lines, and go from there. If there's any coolant leaking into the engine valley, it will run out the rear area of the engine, like you describe. If it's been leaking for any length of time, the coolant will leave a residue that's pretty easy to identify.
    1985 Blazer 6.2
    2001 GMC 2500HD D/A
    dmaxmaverick@thedieselpage.com

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •