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heater valve installation

2K views 18 replies 9 participants last post by  Richard2 
#1 ·
Its amazing how much heat is creeping into my car. My question is. Do I need to bleed the cooling system after installing one, and how's it bled, if needed?
 
#3 · (Edited)
If you plug the hose ends when you cut it then install the valve quickly, you'll lose almost no coolant. If sloth-like in your work speed, you can close the hoses off with clamps or vice-grips if the hose is pliable enough. No need to bleed the system.

Same with changing the radiator fan switch out. Almost no coolant loss if you're organized and think it through.
 
#4 ·
Since Seattle has had 45 days so far this year of above 80F, nearing the record, I have yet to turn the heater shut off valve back on. At least the a/c works (not that it is really needed as required on the East Coast with it's terrible humidity), thanks to the advice Roadtrip gave us when we changed to 134a.

Of course, now the government is scheduled to change the allowed coolant again to something called R-1234yf or something. They do say, though, that it is supposed to be compatible with most systems in cars and appliances.
 
#5 ·
"Its amazing how much heat is creeping into my car."

You are going to notice, unfortunately, that even with a heater shutoff valve, that the creep will continue. Of course the sun in sunny southern California will always be a problem, but the other problem are those hot V6 exhaust manifolds, downpipes, and cat. There is some insulation there to be sure, but not nearly enough. Just preparing you for the worst. Even on a mild overcast day on the east coast, the creep—from exhaust tubing—adds a good 10° F of heat to the HVAC system after about 20-30 minutes of driving, and that's with the heater shutoff valve in off position.
 
#6 · (Edited)
Yes, but the difference is striking in my experience. If one has the heater line open but at min temp, they would have to run the a/c for a short while to cool things down, even here in Seattle, but with the valve closed, they wouldn't have to even think about it.

Now, I've got to do this for the LS. Not as much a problem but still noticeable.

Looking into using the electric valve that others have come up with when I properly identify the actual valve, and which line to cut in the LS.
 
#7 ·
I have no working AC at the moment so I better try to get make it happen before tomorrow is over. Thanks for the help. As for the hose... its the one exiting the head and into the heater core correct? Im trying to figure out coolant circulation. I definitely do not want to overheat the car by cutting into the wrong hose.
 
#8 ·
Yes it's the one coming from the head below the distributor that is the heater core inlet.

I had mentioned that I got these hose pinch clamps at Harbor freight but it was actually Napa Auto Parts and they were about $8/ea. There are two or three different sizes.

So far my electric valve has been working fine with no issues.



 
#10 ·
Paul, could you again review the specific model and price, and where you bought that valve? I'm going to put one in my 91S in lieu of the manual one I do have. Then I'll probably put in one in the LS as well.
 
#11 ·
Word of caution here: You have a lot less space to work with on the 24v models because much shorter hose run off rear head instead of front head set up on 12v models.
 
#13 ·
nice clean engine area Mr Paul. Your AC background is showing. ciao, jc
 
#14 ·
OK, Paul, what have you done at the head connection? There is a short nipple out of the head that is very tight to get a hose and clamp on. All I see in the pic is a copper(?) fitting sticking out at an angle. The nipple come straight out square with the head. What did you do there?
 
#18 ·
Richard, what you are seeing in the picture is the 'T' fitting for the throttle body heater line. I believe you are the one who sent me that as mine was badly corroded. As for the line off the block yes, it is tight but I did not have that much trouble getting it on. Maybe I used metric hose? Can't recall.
 
#15 ·
After about 4 hours trying to get that hose on with a too fat of a hose replacement, I really wanted to remove that aluminum nipple from the head and replace it with something longer. That sucker wouldn't budge!!! I envisioned breaking it and then sending the head out for machine work, so I stopped and consulted the board to see why I was stupid and couldn't get an 8" section of hose on.
 
#16 ·
It has to be a thin hose like the one used on Milano from T-fitting in lower radiator hose that goes to fitting under coolant tank. Hope you found that post with that info.
 
#17 ·
That was one of my first mechanical jobs on the car. I recall you and ChazzyD pointing me in the right direction! Gates hose wouldn't fit, but a cheaper brand from autozone, armor mark I think, was just thin enough vs the proper replacement part.
 
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