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Cooling System Overhaul - Stumped and Frustrated

y5mgisi said:
The pump still creates a negative pressure. Thats what gets it all moving! So, there can be 15psi in the radiator, but a suction before the impeller.
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It's a closed loop...if there is pressure on the front side, there is on the backside, unless something is plugged, correct? Why wouldn't the upper suck closed all the time when the thermostat shut? In a quick search I couldn't find a video of a Chev motor sucking the lower hose flat FWIW.

I just checked my lower hose, no spring. It's solid as a rock even if the engine is "cold", but running. Easily compressed by hand when the engine is off.

I don't want to belabor this, I just know the "must have a spring" thinking isn't correct in all cases. It's easy to check/see, so no reason not to check it I suppose.

BTW, for Darren specifically...if it overheats with the thermostat out, it's definitely a capacity, efficiency, or flow issue, which narrows it down to radiator size, radiator efficiency, or the water pump. I've always wanted to get my hands on one of the "performance" water pumps that purport to move far more coolant (like Stewarts) but I can't justify the cost when I don't have a bonafide need. If your hose didn't come with the spring in it, the manufacturer didn't think you needed one. I don't see any springs listed on rockauto, if I didn't see the hose collapsing at other than idle speeds, I'd not give it a second thought. If it was a real issue, all hoses would come with the spring, and all of us not running one would see the hose collapse. If the hose collapses, you have a restriction to flow somewhere between the pump "outlet" and the passenger side radiator tank. Since your radiator is new, no reason it should be a restriction.
 
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So is an air conditioning system. Is it the same pressure everywhere? I agree tho that a spring isnt a "needed" item.
 
dhcomp said:
They actually had valves on the exhaust? Mine just had the goofy tube that fed warm air into the intake.

But, thanks for checking.
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Yeah, I think that was an "old truck" thing. IIRC it sandwiched between the manifold and exhaust pipe. I had either put it in upside down or rotated wrong.
 
images
 
It's an easy and cheap thing to just try installing the spring in the hose.

Martin
 
You should not need a spring in a good new hose - the materials are better than they used to be.
A collapsed hose could be the result of a old/defective hose or and obstruction upstream from the pump. Imagine if the pump is sucking coolant and there is a clog somewhere upstream. Checking to see if the hose collapses is just one more thing he can check here in trying to diagnose this elusive problem.:dunno:

Do you have a transmission temp guage installed? If not, think about installing one. Besides giving you vital information about the health of your transmission when towing your boat, you could see if there is a correlation to trans temp and motor temp.

I know that you have checked coolant temps many ways, but you can also warm the motor up with a loose radiator cap (no pressure). Use a cheap cooking thermomitor to check the coolant temp as it is warming up - just dip the tip into the coolant.
 
I noticed Summit sells the hose support springs. If you narrow the categories down to Hoses, Radiator it should be on the list of subsections.
 
Keitha said:
You should not need a spring in a good new hose - the materials are better than they used to be.
A collapsed hose could be the result of a old/defective hose or and obstruction upstream from the pump. Imagine if the pump is sucking coolant and there is a clog somewhere upstream. Checking to see if the hose collapses is just one more thing he can check here in trying to diagnose this elusive problem.:dunno:

Do you have a transmission temp guage installed? If not, think about installing one. Besides giving you vital information about the health of your transmission when towing your boat, you could see if there is a correlation to trans temp and motor temp.

I know that you have checked coolant temps many ways, but you can also warm the motor up with a loose radiator cap (no pressure). Use a cheap cooking thermomitor to check the coolant temp as it is warming up - just dip the tip into the coolant.
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Yep, trans temp gauge, in the trans pan. I haven't even gotten the trans gauge to budge recently, when experiencing the motor heat up.
 
dhcomp said:
Yep, trans temp gauge, in the trans pan. I haven't even gotten the trans gauge to budge recently, when experiencing the motor heat up.
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What temp is your 4L80e at when cruising? Mine is typically around 180* in the pan.
 
Thanks for the continued input guys!

My rad hose isn't collapsing. I just don't seem to have enough cooling capacity.

As you all know now, i only have so much patience for diagnostics before i start throwing money at problems. Plus, i don't always have the time, as this truck needs to earn its keep.

I ordered a 3 row champion radiator (716) all aluminum radiator on Sunday night.
http://www.championradiators.com/Chevy-Suburban-radiator-1973-1991

I was nervous about my Thursday tow to Tahoe, as it is expected to be up to 90 or 100 up the grade. No one could express the radiator, but i lucked out, and tracking is showing it arriving on Wed, just in time!

I ordered the standard width one, not the wide one, as i want to see if this will do the trick. If it doesn't, Champion will refund my purchase price, or let me upgrade to a bigger one. I really didn't want to hack up my shroud or try and piece together the larger shroud on such a short time frame.

Hopefully the added cooling capacity of a quality 3 core aluminum unit will make the difference. Keep your fingers crossed, i'll update once i get up to tahoe!
 
I'm glad it doesn't hurt your feelings to dump money into parts. :) But seriously, it is good that they will refund you. I don't see that they have a listing for the huge factory one unfortunately. As I recall, those aren't made in AL (yet), you have to pay the $3-400 for a copper brass still.

Since you don't have the big block radiator, I suspect the one you bought will probably bolt right up (For others who might see/need this, it's a bit shorter than the big block radiator) but you really need to measure hoses now if you are on a time crunch.

Did you verify the hose diameters with yours? For some reason (cost likely) the aftermarket doesn't match the hose diameter up with what the vehicles actually came with.

As I posted in another thread just a few minutes back, an '87 Monte Carlo with 305 uses a lower hose that appears to fit the trucks. Here's the post...I've got the Dayco number in there http://coloradok5.com/forums/showthread.php?t=297122&highlight=radiator

Be warned, Champion says my lower fitting should be 1.38" (Whatever that is supposed to be) but as I mention in that post, it mics at 1.5". Yours says 1.5", I'd expect that to be correct.
 
Checking hose sizes is a good call.

I double checked the core dimensions, and picked the exact one length/width that i have, so it should bolt right up.

We shall see....
 
Champion seems to be 1.5" in and out.

Factory seems to be 1 5/16" in, 1 9/16" out.

Although, those size differences aren't too different. The stock hoses should work fine.
 
These days you would think that it would be easy to find, but there was something to be said for the old days.

I needed a rad hose that had two different end sizes one time, so I just walked down to my local NAPA, and he looked it up in a big Gates book. Found one just the right length and with the right ends.

Surely there is a database out there somewhere that you can put in lengths and end sizes and get a part number.
Of course, odds are you will wind up with a "universal" ribbed one rather than one that is shaped to fit, but they work too.
 
My Dad had a problem with the upper, had to adapt it to the Champion radiator.

GM unfortunately was not consistent however, so even though his is a 454 TBI unit, I wouldn't be surprised if stock hose diameter was different than yours, and that yours will fit right on.

Dunno, the Champion I got at 1.5" wouldn't fit the lower on the '87, whatever size was stock with a 350. Then again, I didn't work real hard to make it fit, it was obvious 1.5" wasn't what the hose was, and the hose that was on there was old and probably wasn't real stretchy. So a newer hose might well have fit ok.

GM obviously had a reason to run a million different combinations of radiator hose fitting sizes, but I don't know what it was.
 
Yah. Stretching 3/8" of an inch, and being 1/8" big on one end....we should be good.

Sometimes, you gotta lube it up and make it happen :waytogo:
 
I'm wishing you luck for a great weekend. You've been through a lot, only 8 pages so far!
 
y5mgisi said:
I got money that says you will have no mo cooling problems with the new rad.
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How much money? About $230? Cause that's what i had to bet :haha:

Glad someone else thinks a legit radiator will do the trick.

Truthfully, i'm disappointed in the Vistapro. Ordered it from Summit, its got a 1yr guarantee. If this Champion works significantly better, i'm going to talk to Summit about a refund. There must be something wrong with this brass one i've got.
 
I would agree, if the radiator ends up making the difference, I'd be asking why a brand new radiator doesn't cool for squat. I think you'll have enough data by then to counter any argument they might come up with. :) Copper/brass or AL, if adequately sized and in good shape, material shouldn't matter THAT much.
 
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