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Discussion Starter #1 (Edited)
I have been smelling coolant for a long time.1998 Suburban 2wd 5.7 1/2 ton 216,400 miles
1.5 years ago I paid and ham handed power tool equipped "mechanic" to strip my harmonic balancer bolt, my oil pan drain bolt,several oil pan bolts.
and who knows what else.
Oh he was supposed to be changing out the intake manifold gaskets -and they were leaking-I don't think they are leaking much now, but I'm dreading ever going back over that to see what else he stripped(idiots should be allowed around electric wrenches!!)

Well I checked my coolant-I had been using a little- maybe 8 ounces 3 months-
Today it seemed to be smelling more-so I checked it- 1.5 GALLONS LOW!!
Looked around-and I found coolant dripping very rapidly from this hose- it seems to be leaking right where the hose bulges out into this bigger hose-there appears to be some sort of metal clamp(not a hose clamp- more some sort of crimp thing)
It seems to be just past a plastic manifold(where 2-3 hoses come together)

My question-just what is this hose- heater hose I'm guessing?
Can I just clamp off both hoses?
Or can I just stick one hose into the other- bypassing the heater??
It would be easier and cheaper to just clamp both hoses-I don't need a heater in South Louisiana
I am broke, what do you think is the cheapest easiest way to just bypass everything for now.
I haven't gotten under the truck yet to get a really good look.
Here is a picture of where it is dripping-where the hose sorta bulges out- it is the hose dead in the middle- second from the bottom-the one that enlarges for some damn reason
What is the simplest cheapest way to get it running quickly-forget the heater for now
Thanks
Charlie
PS it didn't overheat-guess most of the leaking happened after I parked it. P1010057.jpg P1010057.jpg
 

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Can we get a picture with a wider view of the issue? If it is indeed a heater hose, one heater hose should be going to the intake manifold, either all the way at the back of the intake or all the way at the front of it. The other heater hose should be going to the radiator, usually pretty high up on the side tank. If it is a heater hose that's leaking, you can bypass it by getting a heater hose repair kit from the parts store and hooking up the line coming from the intake directly to the hose going to the radiator. That'll bypass the heater.
 

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Discussion Starter #3
Crawdaddy
Thanks for the response
When it quits raining I'll get a picture.
It looks like one hose comes out of the intake,and one comes directly out of the water pump.
They both head rearwardward- BUT THEN 2 hoses turn into 4 or 5 hoses!!

The 2 hoses go into a couple of manifolds and split up-2 going into firewall and two going rearward(one intake one return I guess)
It looks like the hose from the intake manifold springs a leak just after it goes into the splitting manifold-
It is a real mess of hoses in there!!
So there is some sort of cheap out heater hose repair kit- that is good to know.
Autozone will have some sort of generic repair kit that I can adapt to just bypass the whole mess?
Thanks
Charlie
 

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I have been smelling coolant for a long time.1998 Suburban 2wd 5.7 1/2 ton 216,400 miles
1.5 years ago I paid and ham handed power tool equipped "mechanic" to strip my harmonic balancer bolt, my oil pan drain bolt,several oil pan bolts, and who knows what else.
Oh he was supposed to be changing out the intake manifold gaskets
A good reason to work on your own rig Charlie. Just wait till you're not looking & the same "ham handed" mechs twin brother at the tire shop rams your lug nuts on with an impact wrench & warps your drums, as many have posted on here.
 

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Do you have rear heat? If so, the manifold is to split the hot water between the front and rear heaters.
 

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Discussion Starter #6
Stephan

Yes I have 2 good reason to work on my own stuff
1) Broke
2) Don't have to worry about some FU making things worse- heck I can make things worse for free-I don't need to pay anyone to do it!!
I was actually happy to see the heater hose leaking- sure beats manifold gaskets, or radiator, or heater core.
Can't say I was happy to see it was 1.5 GALLONS LOW!!But most must have leaked after I got home.Probably been seeping for a while, but it must have really split/blew! Hope I didn't miss the gauge pegging itself!
Charlie
 

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You can't block the heater hose, but you can bypass the heater cores. You just need to make sure the hose coming from the top/front of the intake manifold returns to either the water pump or radiator.
 

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Discussion Starter #8
2COR517
Right I wasn't thinking.
If I clamped a pressurized hose-BOOM- coolant would blow all over the place.
I kinda thought that maybe the heater was supplied as some sort of a partial bypass circuit where it was getting some low pressure flow, but if blocked would just bypass like a plugged oil filter.
So the heater core ALWAYS is getting fresh hot coolant- but only pumps heat into the cabin when fans are on and some duct is open?

Two questions;
1) is the line to the top of the water pump a return line?So the line from the intake is the line sending coolant to the cores?
2) In my picture-there is a line-probably the leaky one-that suddenly is sleeved in a floppy rubber sleeve. WHY is it sleeved like that-what is that kinda fragile looking rubber sleeve for?? It is clapped on with a narrow metal clamp-which might be where the leak is- it- the metal clamp might have cut the hose?Sleeve doesn't look like it would protect the line from abrasion much , but maybe it does???
Thanks
Charlie
PS- I'm going to spend $20 on a whole bunch of hose connectors-ebay- various sizes and some are different ODs on either end.Pretty sure the lines are different diameters,so I need the connectors with two different ends- think they are 5/8 x7/8 OD or some such.
 

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You can't block the heater hose because its part of the cooling circuit for the engine. Coolant flows from the intake fitting, through the heater core, and back to the water pump. From the water pump, through the block, up through the heads, into the intake manifold, back out the heater hose. As the engine warms, the thermostat opens and directs some of the coolant to the radiator through the upper hose. The coolant transfers heat to the air as it flows through the radiator, the cooled coolant returns back to the water pump in the lower hose. The cooled coolant mixes with the coolant coming back from the heater core and circulates through the engine to keep it cool.

So yes, hot coolant is always flowing through the heater core. The exception would be when you go to Max AC. There should be a vacuum operated bypass valve in the heater core lines. When you switch max AC, the valve "closes" and directs hot coolant directly back to the water pump.

There are two size heater hose lines. 5/8 id connects the intake fitting to the heater core. 3/4 id connects the heater core to the water pump. So the only adapter you need is a 5/8 x 3/4.

If you have a heater hose connected to the radiator, that's fine. It still goes back to the water pump through the lower hose. Some vehicles are setup this way to warm the transmission up faster, and it's possible that if you have both front and rear heat one goes to the water pump the other to the radiator.
 

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Discussion Starter #10
2COR517
Thanks.
So the heater circuit gets the full flow of the coolant circuit except after the thermostat opens and sends a little to the radiator- ??
Wow I never have had a heater line leak in 40 years of screwing with cars/trucks etc- never gave it any thought. I always pictured it as having no flow until you hot the heater switch and some sort of valve opened.
The kit I ordered-$15 delivered has several 5/8 to 3/4 fittings-and a bunch of others.It would have been 1/2 that to just get the single fitting-and I might eventually use one of the other straight sizes to "repair" cut out my leak- I think the leak is to the back circuit.
When it quits raining I'll get a better look
Thanks
Charlie
 

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Discussion Starter #11 (Edited)
I got a better look at it yesterday.
The triple connector-one that gets a hose from the intake(is the intake the line that pumps to the cores or is it the return line)has cracked in two-coolant water gushes out!

It is infinitely more complicated under there than I would have guessed.
That triple connector sends a line to the 4 way connector-and there is another triple connector under there.

Why so many connectors- I would have thought two triple connectors would be eought to supply drain two cores??
What is up?
Thanks
Charlie
 

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Who knows what GM was thinking when they designed most of this stuff, they tend to make the easy things way more complex than they should be. Since you found the source of the leak, I would just order the new parts, pick up some new coolant, figure out a good way to drain the coolant without it getting all over the ground, and go ahead and just swap it out.

If you can't afford to do that, then pick up some JB weld, make sure the cracked area is clean, and JB weld the crap out of it...I know it's a backyard mechanic fix, but you gotta do what you gotta do sometimes, just make sure you replace that part, cause the JB weld thing is just a temporary fix until you can get the money for the part.
 

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Discussion Starter #13
Ethan
I lucked out and found a cheapo T- fitting at AutoZone-$5.48.
It was a pain -45 minutes to 1 hour- getting the broken old fitting out- it is plastic ans just broke into pieces-I had to carefully fish all the little pieces out,and put those crummy squeeze hose fitting back on.
It is waaaay complicated
The line from the intake goes into a triple fitting-then it sends one line to the back and one line into a 4- fitting manifold
The line from the water pump does the same thing- 1 into three- then one into 4??
Buddy tells me that 4 way fitting is some sort of bypass so most of the coolant doesn't go to the heater cores before the thermostat opens-the bypass is a dumb bypass-always open always flowing- but when the thermostat opens it changes the relative flow
Seems waaay to complicated- but must be a good reason to do it that way.
Yes I have used JB weld- but the plastic fittings are so brittle/thin it wouldn't work for them- 14 years old-they just crumble!
Thanks
Charlie
 

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The four hose fitting is the bypass valve I was speaking of. Your buddy is correct that it is a bypass, but he has no idea what it does or why. When you go to Max AC/recirculate, the bypass valve essentially stops coolant from flowing into the heater core.
 

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Discussion Starter #15
2COR
Thanks.
Just how does that bypass work?? It doesn't have any mechanical or electrical connection to it(that I can see), so how does it open/close?
Looks like it is always open? It doesn't seem to have any valve-or anything connection to tell it to open/shut??
Did I miss an electrical connection?
Charlie
 

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Operates on vacuum. There should be a line running to a solenoid mounted on the firewall in the vicinity of the accumulator. Source vacuum is a hard line running across the engine to the PCV vacuum fitting.
 

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That's evil, the way they did that one. The same exact thing could be accomplished, requiring only a three-way connector to supply hot coolant to the cores, and a three-way for the return.
 

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Discussion Starter #18
2COR
I see it now.I didn't realize that the part with the vacuum line was attached to the 4 port manifold.So many lines parts under there,I missed it.
Geez-I have better not break that 4 way manifold- it would be more expensive than the $5.48 3 way T- fitting.
I think my buddy actually said what you said- he was going on about the heater cores heating incoming air
BEFORE IT GETS TO THE AC FOR SOME REASON- and my eyes rolled back in my head when I heard heating AC air before cooling it.
I might have gotten the above wrong-on phone-and once I heard heating ac air(maybe something to do with moisture?I just went WTF and didn't want to hear anymore.
Thanks
Chris Miller- yeah it is waaaay more complicated than the last vehicle-1971 Cuda in 1977- that I had to fool with anything to do with the heater hoses.Heck I think I just completely bypassed the heater with a simple splice connection.South Louisiana who needs a heater(except for defogging the windshield)
Yes, that sucker is COMPLICATED!! good thing heaters systems rarely break- but this 14 year old 216,600 mile Suburban is probably the oldest "car" I've ever owned($$ problems- I will probably get a 2004 when I become more flush)
tHANKS
cHARLIE
 

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Glad you're getting it figured out Charlie. And learning all the way. All the air passes over the AC Evaporator. That way you can have dry, warm air for defrost.

The four port bypass valves are likely just as brittle as the Tees were. Go gently, or just replace if you can afford to. You can bypass them with no major impact.
 

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Discussion Starter #20
2COR
Yeah, the T- fitting was so brittle it was a miracle it held for so long.Fact is I had been smelling coolant for maybe 2 years-and had been adding coolant about as long- not much- maybe 6 ounces every month or so.
I just checked ebay- that 4way fitting is on for just $30- not too bad a price. If I get a bit more flush(selling motorcycle parts on ebay) I'll pick it up.
I was pretty gentle changing the T- fitting, but the old was was sooo brittle-that 4 way will croak soon enough-and the other 3 way fitting-a Y fitting- probably in same shape.
Can't complain-14 years and 216,400 miles(last 22000 miles are mine)- they sure did their job
Thanks
Charlie
 
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