How do I bypass the rear heat valve/solenoid?

[Philly758]

Hot water enters front heater core IF the shutoff valve is turned to ON.
Otherwise, the hot water is kept out of the passenger compartment.
Allows A/C to flow withOUT having to pass next to the heated core.

Upper hose in pic is cooler water OUT of the heater core -

[ http://digitalcartography.com/n0eq/astro/Heater-04.jpg ]

Excuse me for being slow and possibly repeating exactly what you said, but until 24 hours ago I knew nothing about how a cooling system functions. So my question is...

Does that shutoff valve you added go in the same location that a flushing tee would? Meaning, that if I were add a flushing tee this weekend when I flush my cooling system to make things quick, easy and not make a mess in someone else's garage... I could easily add a valve like this next summer to help my A/C run more efficiently? If its that simple, it seems like a no brainer to me.

I know people are opposed to cutting into hoses and increasing the potential for leaks, but the hose can easily be replaced if problems arise, i'm not too worried about it.

Thanks.

[Lumpy]

...Does that shutoff valve you added go in the same location that a flushing tee would?...

I would think so, yes.
In mine, there would not have been room for one of those flush thingies. The rubber part
of the (now deleted) plumbing was only a couple inches long. The rest was metal pipe.

And in my GenI style, or maybe just my year, there is no valve that cut OFF the flow of
hot H2O to the heater core. In other models that valve that everyone is talking about
shuts off the water till you turn on the heat at the dash. So for those models, you'd want
to turn the heater ON when you flushed. Which is what all the directions always say anyway.

But I think(?) the simple answer is, yes. Install the flushie anywhere you can reach.


Lump

[scottnhalifax]

well, i had the same issue, but today after thinking about the setup and splicing the hoses together all i did was splice the vaccum hose together from rear heater valve. just by pass the electric switch that allows the vaccum to be routed to the valve. done in under 20 minutes. now everyone is warm. well hot.
cheers great site

[Lumpy]

Seems there are several variants on this valve and hot water routing scheme. Some with vacuum, some
with electric, some without altogether. One thing seems universal...get rid of the valve and
the heater gets HOT right NOW!

That's great for the 4 days out of the year that heat is needed here in Phoenix.


Lump

[chevymaher]

It has reached 95 degrees 3X here already. So As I type I am following in the master Lumpy's footsteps and installing a ball check valve in the heater core circuit. No sense in competing with the heater if you don't have to.

[chevymaher]

Done 90 degrees now. Took a trip let it sit in the sun. Started it to leave. Much better. In traffic and sitting it is much cooler. Driving not a big change. I am good with any improvement. Heat soak through the little tin door in the air handler Eliminated.

[Jasen]

Hey, that ballcock is even idiot proof, it say's on/off

[chevymaher]

Hey, that ballcock is even idiot proof, it say's on/off

I have only had it a few hours. Give me a chance I will figure out how to mess up.

[Jasen]

Hey, that ballcock is even idiot proof, it say's on/off

I have only had it a few hours. Give me a chance I will figure out how to mess up.

If you have trouble with that let me know, I'm sure I can help you screw it up reeeeal good

[chevymaher]

If you have trouble with that let me know, I'm sure I can help you screw it up reeeeal good

It is 95 degrees now. I drove to the store and went inside. Let it sit in the sun 45 minutes. Worst case scenario. Come out sit in traffic 4 lights in a row before open road. Ice cold before second light. Like sitting in the living room.

So I doing something wrong may need your help after all.

[Jasen]

[paintdrying]

Chevy, little easier if you get a 3/4 inch pex shut off. They just clamp right in. Pex is that plastic crap that has replaced almost all copper pipe.

[Shad0wXCalibur]

Ok so is bypassing the heater core in the summer supposed to noticeably help keep it cooler inside? That would be great because it's getting close to the 100's here already and the A/C works better than it ever has after I had a shop fix it but it still only works it's best at speed. Not enough airflow across the condenser when sitting in traffic.

[paintdrying]

i put those valvess in all my cars. yeah, they seem to help. but yourac could be something else

[chevymaher]

Ok so is bypassing the heater core in the summer supposed to noticeably help keep it cooler inside? That would be great because it's getting close to the 100's here already and the A/C works better than it ever has after I had a shop fix it but it still only works it's best at speed. Not enough airflow across the condenser when sitting in traffic.

It works better sitting still. Driving it about the same. Biggest thing was there was a occasional waft of warm air mixed in. I found that annoying hitting me in the face.

So yes it does work better. After driving 5 minutes or more in 90-95 degree weather. I got the slide bar down to half, on bi-level cooling, blower on low which is medium to everybody who has all their blower speeds.

Added nice feature is vent. If it only 80 or so. It is cool air. with the blower on it is enough unless it been sitting in the sun a while before you drive it.

Bad thing is if you live in Ky. Our temps fluctuate so wildly. It can be 50 in the morning and 90 by noon. So I been leaving the heat on unless it supposed to get to 90 or better. Which is the only time there a noticable difference in cooling to me.

Electric fan fixes the sitting in traffic condenser flow issue. After that the low idle refrigerant pressure drops after idling a while. But it stays ice cold after pulling to a stop for 5 minutes anyway. After that it still alot colder that before the electric fan.

[Shad0wXCalibur]

I've thought about a condenser fan but I don't know how to wire it where it will turn back off at speed. I actually already have a fan laying around that would probably work. It's somewhat cold sitting still but definitely cold as soon as I'm steady cruising from all the airflow cooling down the condenser.

Plus, my alternator hates me already. When it gets hot under the hood, the alternator gets heat soaked and drops voltage when my front and rear a/c blower motors are on, 80 watt headlights, foglights, and back-up lights are on all at the same time.

I'm thinking of trying to just restrict the heater core flow instead and see what that does instead of blocking it off entirely. Rarely ever gets below freezing here and I would only need enough heat for that.

[chevymaher]

To tell the truth I never did get a control for my fan. Van is on it is running. I just have a relay. Had it on all last winter.
I got a lifetime warentee. It don't make it run to cool in the winter. I just let it run.
Can't see paying 40-45 bucks for something I will never notice a difference. Or will it make a difference. It works fine, so if it ain't broke dont fix it.

Edit...Electric fan. I removed all the shrouding. Alternator stays cool now. I used to have the heat problem to. Voltage dropping.