1990m heater hose disconnect

Discussion in 'GM Powertrain' started by RATRODKING, Dec 24, 2008.


    RATRODKING Rockstar 100 Posts

    hello guys.
    i have a 1990 chevy silverado 4x4 with a 5.7 engine.

    on the rear passenger side of the intake manifold there is a factory heater hose connection half metal and half rubber hose.
    mine is corroded, 111k miles, and looks like a pain to change.
    is it gonna give me fits ?
    why did chevrolet make this style connector, and not just use a hose clamp on a fitting ?

    a friend told me they sometimes break in the intake and are a pain to get out.

    also, is there a fitting i could use in place of this style connector, and just slide a hose over it and use a hose clamp ?

    thanks much. i just found this site and will visit frequently.


    RATRODKING Rockstar 100 Posts

    guys, i bought the aluminum bent tube with heater hose crimped on it and the quick disconnect fitting that goes into the intake from my local chevy dealer yesterday.

    the more i looked at it, the more i thought how stupid it is to have a conection like that.
    i looked at my nephews 1994 4x4 truck, same engine, and his just has a threaded nipple with the heater hose clamped on it.

    so, i went to home depot, got a 1/2 npt brass fitting for 4 bucks, and will try that instead for the 85 dollars the factory type fitting cost me, and if it works, which i dont see why it would not, i am getting my 85 bucks back from chevy.

    i will let you know how it comes out. if weather permits, i am gonna do it today, along with an oil change and a complete tune up.

  3. Crawdaddy

    Crawdaddy All hail the Mad King!! Staff Member 5+ Years 1000 Posts Platinum Contributor

    The only word of caution I have to you is to watch out with the brass fitting. From what I've been told, brass doesn't like extreme heat, then cooling down. From what I've been told, this makes the brass very brittle. However, I used a couple brass fittings with my transmission cooler and they seem to have done just fine so far.

    RATRODKING Rockstar 100 Posts

    thanks for the tip on the brass fitting crawdaddy. i rememebr back in the day, having some brass fittings for oil pressure and water temp gauges, so hopefully i will be fine. by i know my luck. LOL.

    i just cant see me installing the factory fitting again. although this one lasted 18 years and 111k miles. it seems like a very weak point in the system.

    i went out there this morning and sure enough, it broke in the intake. the idiotic engineers at chevy made the fitting out of pot metal. so my brother is searching for a big enough easy out to get it removed.

    thanks again, and i will let you all know how it turned out when i am actually finished.

  5. mrfixdit

    mrfixdit Rockstar 100 Posts

    I just had the pleasure of doing this same job yesterday. Easy outs are tapered and the pot metal is too brittle to get a grip (you've probably already found this out) I took a small roll of band-aid gause and attatched some fishing line to it(so I don't lose it if it slips further down the hole) then put it down the hole to catch any falling debris. Then I used a 1/4 in. wood drill paddle bit because it had the perfect tip for chiseling the rest of the fitting out. The crap metal is very brittle and chisels out fairly easy. Got it out in three pieces with minimal damage to threads. New fitting from Advance auto ($12 and REAL steel) and a little black poly sealant its better than new.

    RATRODKING Rockstar 100 Posts

    yep, i did mine christmas day. it did break, then i trid a large easy out, which like you said, the pot metal is too soft and when applying pressure it actually acted like a sponge and would squeeze coolant out of the porous pot metal.

    i also put a piece of red rag down the hole, to catch debris, but a coup,e of chunks fell in. hope they dont give me aproblem in the future. i used a little chisel to break it apart.

    i then tapped the threads with a 1/2 NPT tap i had, then went to home depot and got a brass fitting with the same threads, wrapped it with white plumbers tape, screwed it in, then put a length of heater hose from it to the heater core.

    working fine, but in the beginning it had a lot of air in the system, making bubbling sounds in the heater core inside the cab.

    got most of the air out but still has a small amount of air i need to get out.

    i took my 85 dollar fitting and original aluminum / rubber hose back to chevy to get my money back. there was no way i ws going to put that thing back in my truck. the engineers who thought up that design were idiots.


Share This Page

Newest Gallery Photos