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91 blazer cooling/heater hose routing ???'s

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by mofugly13, Feb 3, 2003.

  1. mofugly13

    mofugly13 1 ton bucket of rust Premium Member

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    91 blazer cooling/heater hose routing ???\'s

    My 73 K5 with 91 front end had the wrong radiator and the PO had it held in with tie wire, so I went and picked up a new radiator for a 91 blazer with the heater return fitting on it. The PO had swapped in a 327 and on the he ran the heater hose (3/4"hose) from the top of the water pump to the heater core, and the return (5/8" hose) to a fitting on the intake manifold just to the left of the water neck. Well now that I have a heater return fitting on the radiator, I wanted to run the 5/8" hose to that and put a temerature sensor where the fitting on the head was. I have no temperature sensor and have no place on my motor to put one except in this hole by the water neck. Now, I thought the 5/8 hose went to the radiator, but that fitting is 3/4. So, can anyone with a 91 or just anyone who knows tell me how the hoses are supposed to be routed? Thanks. /forums/images/graemlins/ears.gif
     
  2. unsane

    unsane Guest

    Re: 91 blazer cooling/heater hose routing ???\'s

    well i have an 89 and there s no heater hose that goes to the radiator. I can tell you that I went to AutoZone the other day to get a new water neck for my 89, and he part guy tried to give me the wrong one. The one he tried to give me sounds like just what you need. It had 2 heater hose nipples on the water neck! Hell go ask for a new water neck for an 89 gmc jimmy and see if it will work for ya.
     
  3. u2slow

    u2slow 1/2 ton status

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    Re: 91 blazer cooling/heater hose routing ???\'s

    My '91 crewcab has a TBI 350 (but not for long /forums/images/graemlins/grin.gif). One heater hose goes to the radiator. The other goes into the back of the TBI intake.
     
  4. Dale fan

    Dale fan 1/2 ton status

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    Re: 91 blazer cooling/heater hose routing ???\'s

    I just did a core swap on my 90 a few weeks ago and forgot the routing already so I went out and took a look for you. The 3/4 hose that comes off the top tube on the core goes to the radiator. The bottom 5/8 hose goes over to the rear of the intake. Of course the small hose on the radiator neck runs over to the overflow tank.
     
  5. mofugly13

    mofugly13 1 ton bucket of rust Premium Member

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    Re: 91 blazer cooling/heater hose routing ???\'s

    Thanks fellas. I'm gonna run the 3/4 hose to the radiator and the 5/8 to the top of the water pump. Sound like the right idea? I have no fitting or place for a fitting at the back of my intake, but I have a carb, not FI. The only spot for a heater hose fitting is right next to the water neck. Now if I could only find out where to put a temp sensor...
     
  6. Dale fan

    Dale fan 1/2 ton status

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    Re: 91 blazer cooling/heater hose routing ???\'s

    I would make sure which way the flow should be. You said your 5/8 went by the water neck on your old setup. You wouldn't want to blow your heater core. They're a pain, trust me. /forums/images/graemlins/mad.gif Maybe you or your radiator shop could just block off the fittings on the newer radiator and you could keep your hoses the same way that they were.
     
  7. jakeslim

    jakeslim 1/2 ton status

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    Re: 91 blazer cooling/heater hose routing ???\'s

    is there an inlet on the front of the intake? Thats where mine is.
     
  8. mofugly13

    mofugly13 1 ton bucket of rust Premium Member

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    Re: 91 blazer cooling/heater hose routing ???\'s

    Yeah. As you look at the engine, its about 3" left of thre water neck. Right now my hoses are back the way they were before, but I really want to have a working temperature guage, and I cant find any spot to put a sensor except this threaded hole on the intake. /forums/images/graemlins/confused.gif
     

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