Cooling System Mystery Part

[DMGroh]

This appears to be a 1-way valve in my heater hose circuit (lower nipple on water pump to lower nipple on heater core). The actual part is located about 4-5" just below the radiator cap. Small pieces of plastic fell out when I removed the part, and it has a directional arrow that (on my car, at least) pointed toward the heater core. No mention or illustration in Helm, Hayne or Chilton.

 

[DMGroh]

Sorry, it's a 96 LT-1

 

[So Bay Vetter]

DM-

I have the factory service manuals. I've looked thru both of them for everything related to heater hoses. The exploded parts view(s) clearly show the component but, nowhere is it identified. It is probably a check valve to keep fluid from going backward down the line to the water pump. I'm sure if it was really crucial they would have identified it but, nonetheless, replacing it to keep crap from backing into the water pump probably isn't a bad idea. Hope this helps

 

[WhalePirot]

I've never seen anything like this, except for system flushing parts, which it is not.

Maybe it is one of those miracle parts that helps deliver 100 mpg. :L

 

[DMGroh]

Junkie: Thanks, wanna bet I'll be at the Dealer's Parts Window soon?

So Bay: What page of Helm did you find it? BTW, used to live in El Porto, MB.

 

[So Bay Vetter]

DM-
I don't think I have Helm manuals. Mine are a 2 volume set from GM with red covers. In any case, the illustration is on pg 6-176 of book 2 and it is mentioned only as "remove heater hoses" under "remove heater core " in book1 pg 1B-30. I still can't figure out how to scan and post to this web site but I can probably e-mail them to you. I'm not sure whether it will help since the part goes unmentioned in both cases.

BTW - I grew up surfing in El Porto and still go out there with my son.

 

[DMGroh]

Thanks again. Helm & GM are the same. Now I see the "part".

 

[DMGroh]

Junkie: I see that service/parts manuals are like tools....you can't have enough!

 

[DMGroh]

Dealer has to back-order the part, but claims it's not only LT-1, but all cars (but doesn't stock the part ??). Claims it only allows coolant flow to heater core when "heat is on". I think the earlier post description above is more correct.

Anybody know more about this? I believe it has a small ball held captive inside, similar to a pvc valve. The plastic retainers broke and the ball is loose somewhere in the coolant system...hopefully in the heater core and not the water pump.

Can anybody shed more light on this part....is it really needed, or only a convenience item that keeps cold coolant from the heater core until the system reaches a pre-determined temperature? Right now, I have a 1/2" copper nipple in its place.

 

[DanC]

I started a similar thread last fall. I think I finally got the answer to "what is it?"

See if this helps (if I did the link right).

93 with little/no heat from HVAC


http://www.corvetteactioncenter.com/forums/showthread.php?t=57104&highlight=danc

 

[DMGroh]

Thanks for the help. I was going to backflush the core to hopefully remove the ball (if that's what it is), but according to Jim McCloud, probably flush is several times each way (makes sense). Did I understand your old posts that the check valve closes against the flow instead of with the flow?

 

[Drjohn]

Is this it?


http://www.artscorvetteparts.com/part_detail.aspx?item_guid=62e88cc1-51ef-46a9-b751-fa1325d3b894

 

[DanC]

No ball in the device. If memory serves, the disk seats with flow, restricting flow through the heater core at high coolant flow rates, presumably at higher engine rpm's.

During "normal" engine speeds, there is room around the disk for coolant to flow, so coolant can flow through and around the disk. At high engine rpm's, it seems the disk will seat at the outlet end of the housing, allowing coolant to flow only through the orifice, presumably (there's that word again) reducing flow and pressure to the heater core.

One of the comments in my thread seems logical; to protect the core from excessive pressure at high engine rpm's, however, I've never seen this type of device before.

Hope this helps. DrJohn's picture is it. How'd you do that?

 

[Drjohn]

Those guys have a ton of parts. I bought this part http://www.artscorvetteparts.com/part_detail.aspx?item_guid=e469bcd4-b7d9-41e2-b138-dcee35aeb114a couple of weeks ago. I thought I'd have to wait an extra weekend to install, but it came by Friday. It's the only thing I've bought from them, but they seem okay.

I was having trouble with the temp registering low, but the engine in fact running hot. I thought the thermostat was stuck open from the guage reading, but noticed a leak in the linked part, resulting in low coolant and low pressure.

Running at the correct temp now, and getting better mileage. I also took the opportunity to bypass the coolant tube through the throttle body so I don't need to drain the coolant again just to swap out the TB.

Hopefully, the previous owner didn't let it run that hot for very long.

 

[DMGroh]

Yes, that's the part in question. The dealer quoted the same $16, but I'll pay the postage and not have the pleasure of driving to the dealer twice (pay first, they order it, go back to pick up...great service, huh?). It also sounds like it's probably better to put in the part to protect the system.

Question: I originally assumed that there was a check ball (like a pcv valve), but apparently from reading the posts, it is some kind of disk with a hole in the center. Would that be a more accurate description? Or is it the disk AND the ball? In other words, do I have to worry about flushing out the ball (that may not even exist) from my heater core? I did extract the spring and what looked like a smaller version of a typical garden hose rubber washer from the inside of the valve.

Anyway, Thanks Guys for all the help.

 

[Drjohn]

When you order the new one, ask them if they know what's inside. You could buy two and take one apart if you're really curious (you could give it to my 8-year-old, he's good at taking stuff apart).

I'm guessing if you flush the system, you're in the clear.

 

[DanC]

Last fall when I had took my valve out, it appeared to be intact, and only a spring and disk were inside, no ball.

If there were a ball, it would shut off the flow, and it looks to me like the intent is to take a pressure drop across the valve at high rpm's, not stop the flow.

Just my .02 cents.

Good luck.

 

[DMGroh]

I'll know for sure when I get the new part. Thanks again for all the help!

 

[DMGroh]

Finally got the part from the dealer. I know it's the correct part because they both say "assembled in Mexico". The part has a directional arrow, and my old part pointed toward the heater core. Just a spring loaded disk inside.

Stopped in the Service Dept at the dealer (Huffines Chev) to talk with the Corvette "expert", just in case my original was installed wrong. He didn't have a clue... said it didn't matter which way to put it in (why is there a freakin arrow on the damn part!), and couldn't remember which way the coolant flowed in the heater hose..toward the pump or toward the core! Just walked out shaking my head and mumbling under my breath.

But I thanked him (for reminding me again why I avoid the dealer for service work whenever possible....and spending $135 for the Helm manual).

 

[Drjohn]

Dealers anger me.


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