lookforjoe
True Classic
Karl clarified the location, I apologize I didn't in my post - I was assuming the stock location was a known given - should have remembered what happens when one assumes too much 
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Heater valve on AC equipped X1/9's
- Thread starter Dr.Jeff
- Start date
LarryC
Curator of #10105275
Yes, the AC rebuild thread is here
https://xwebforums.com/forum/index....d-upgrade-what-the-wife-wants-she-gets.21920/
and here (for the AC-Heater box rebuild)
http://xwebforums.com/forum/index.php?threads/20043/
And I just spent a lot of time- and with great pain!- restoring all the images on the first one. Still working on the second one. Half-way there.
kmead
Old enough to know better
Thank you, we all appreciate both your original effort and going back to redo parts of it. Greatly appreciated by all of us who have an AC equipped X. Something I didn't appreciate until recently. Thanks.
Karl
Rod Midkiff
True Classic
I WILL make a copy of this, this time. even have a binding machine will bind the pages and put it away.
This is what I did (with lots if pictures):
https://xwebforums.com/forum/index....-control-valve-replacement.27435/#post-228926
Dr.Jeff
True Classic
Nicely done. Thanks.
The linked address (at the bottom of his post) has the info, look there.
kmead
Old enough to know better
Nicely done indeed. Thank you. I must have been very busy in April of 2015 to not remember this.
kmead
Old enough to know better
I picked up a vacuum version of the 4 way bypass type heater valve. The one I bought from Amazon was under 14 and its normally closed (as a vacuum actuated object), Four Seasons 74781 Heater Valve.
From the looks of things, if you ignore the vacuum actuator, it would be a great fit alongside the HVAC box. The distance between the two feeds facing the heater core is somewhat less than the core outlets but within what a hose can easily accommodate. The inlets of the valve would be well placed for the supply and the return hose to go around as it does today. One might want to try to find some molded hoses to make the transition but standard hoses would likely work.
The actuating cable would be easy to accommodate along the side with some rerouting around the right side of the box versus along the left side. With a cable actuation it wouldn't interfere with the electrical box tray in either position. There is room for everything there.
It would also be possible to put it where the existing valve is but it would be more difficult to service there.
Pics below are from my 87 with AC.
I will take some pics a bit later of my non AC car.
So this could give us a full bypass heater valve that would be easily serviceable. It puts it in the passenger compartment which means there will always be heat circulating which is somewhat less than ideal but it doesn't require either a vacuum system to actuate, an electrical system to actuate or ? If it was remotely located in the engine compartment
From the looks of things, if you ignore the vacuum actuator, it would be a great fit alongside the HVAC box. The distance between the two feeds facing the heater core is somewhat less than the core outlets but within what a hose can easily accommodate. The inlets of the valve would be well placed for the supply and the return hose to go around as it does today. One might want to try to find some molded hoses to make the transition but standard hoses would likely work.
The actuating cable would be easy to accommodate along the side with some rerouting around the right side of the box versus along the left side. With a cable actuation it wouldn't interfere with the electrical box tray in either position. There is room for everything there.
It would also be possible to put it where the existing valve is but it would be more difficult to service there.
Pics below are from my 87 with AC.
I will take some pics a bit later of my non AC car.
So this could give us a full bypass heater valve that would be easily serviceable. It puts it in the passenger compartment which means there will always be heat circulating which is somewhat less than ideal but it doesn't require either a vacuum system to actuate, an electrical system to actuate or ? If it was remotely located in the engine compartment
Dr.Jeff
True Classic
Nice Karl. How is the plumbing configured for this bypass type valve?
If I stay with a standard (non-bypass) valve I will try using the common VW item. It is plastic, right hose size, simple, small, and readily available everywhere at a ridiculous price (like under $3).
I took another look at the AC/heat box and agree the right side seems to offer the best fit/access inside the cabin (still not decided about putting it inside or under the hood).
Another weird design feature is how one of the heat hoses passes from the engine bay directly under the floor pan (into the tunnel), while the other hose crosses through a hole in the rear bulkhead, along the spare tire well, down toward the e-brake and through the tunnel. When the time comes to re-do mine I will look into the option of running both hoses under the pan, eliminating the pass through the interior compartment.
If I stay with a standard (non-bypass) valve I will try using the common VW item. It is plastic, right hose size, simple, small, and readily available everywhere at a ridiculous price (like under $3).
I took another look at the AC/heat box and agree the right side seems to offer the best fit/access inside the cabin (still not decided about putting it inside or under the hood).
Another weird design feature is how one of the heat hoses passes from the engine bay directly under the floor pan (into the tunnel), while the other hose crosses through a hole in the rear bulkhead, along the spare tire well, down toward the e-brake and through the tunnel. When the time comes to re-do mine I will look into the option of running both hoses under the pan, eliminating the pass through the interior compartment.
kmead
Old enough to know better
This the same valve different actuation.
When half open the flow will be muddled so it will likely be either fully closed, fully open or nearly fully open for decent flow through the heater core.
The logic for the heater hose routing was likely due to those of us who live in actually cold climates, running the heated supply in the cabin reduces heat loss from the hose and heats the interior while the return running outside the car will see negligible change as it is likely more nearly at the ambient or it just doesn't matter how much cooler it gets.
I think there would likely be plenty of room for the valve you are considering on the side of the heater box, the existing heater lines run in a recess relative to the overall width of the heater core box so as long as the valve was installed conformal with the existing hose routing.
In regards to your rerouting it would lend itself very well to putting a bypass valve in the engine compartment. If it could be placed fairly low, the two upward facing outlets would be routed to the engine and the downward ones to the underside of the car. This would keep the heat out and could be a more seasonal changeover with a pull cable in the engine compartment. It might even mean you don't need to reconfigure your hose routing...
Dr.Jeff
True Classic
Thanks KM.
With the valve being the control for the level of heat offered inside the vehicle (how hot you want to be), I wonder if this bypass style will significantly differ that adjustment. What I mean is how well can the interior temp be controlled, how precise (for lack of better word) is the flow control? We rarely use "full" heat.
But I do see advantages with the constant flow keeping the hoses and valve clean. However it will not help in maintaining the heater core's innards (a problem here due to lack of use). Some vehicles are designed where a small amount of coolant is allowed to constantly pass through the core for that very reason. I wonder if any of these bypass valves do that (intentionally or otherwise)?
For me this would definitely have to be placed in the engine compartment; too much heat flowing through the cabin otherwise. And the one drawback I see in mounting the valve in the engine bay is the long actuating cable needed (I'm not real big on vacuum or electronic controls for this application).
With the valve being the control for the level of heat offered inside the vehicle (how hot you want to be), I wonder if this bypass style will significantly differ that adjustment. What I mean is how well can the interior temp be controlled, how precise (for lack of better word) is the flow control? We rarely use "full" heat.
But I do see advantages with the constant flow keeping the hoses and valve clean. However it will not help in maintaining the heater core's innards (a problem here due to lack of use). Some vehicles are designed where a small amount of coolant is allowed to constantly pass through the core for that very reason. I wonder if any of these bypass valves do that (intentionally or otherwise)?
For me this would definitely have to be placed in the engine compartment; too much heat flowing through the cabin otherwise. And the one drawback I see in mounting the valve in the engine bay is the long actuating cable needed (I'm not real big on vacuum or electronic controls for this application).
kmead
Old enough to know better
In looking at the space available and routing of the lines for a non AC car this sort of bypass valve would be best suited to being mounted right behind (forward) of the heater box right above where the hoses come up out of the tunnel and use the existing frozen open heater valve and the existing rigid line to feed short sections of hose to the top of the new valve. It will actually be pretty accessible for replacement and the existing actuation cable should reach to that position.
Attachments
lookforjoe
True Classic
WoW! There's so much space in there without the AC heater box!
There is no heat transfer with a standard 2 port heater valve when closed, since the heat is only present when there is active flow, or were you referring to a 4 port valve as Karl illustrated?
There is no heat transfer with a standard 2 port heater valve when closed, since the heat is only present when there is active flow, or were you referring to a 4 port valve as Karl illustrated?
LarryC
Curator of #10105275
There is a dedicated pipe for the one heater hose in the coolant tunnel. So you will need to run another one for an outside-of-the-cabin route for the second hose. Not sure there is room for that.
LarryC
Curator of #10105275
The problem is that most of those plastic valves don't seal all that well. So there is definitely flow even when closed. We discovered this over on one of the American truck sites where we worry about unnecessary heat coming from the heater in the summer- because of one of those plastic valves. They are not that good. The beauty of the original X 1/9 AC valve is it is a clean seal-off of water flow in the summer. In fact, I was thinking of using an X 1/9 heater valve in my Bronco to finally solve that very problem.WoW! There's so much space in there without the AC heater box!
There is no heat transfer with a standard 2 port heater valve when closed, since the heat is only present when there is active flow, or were you referring to a 4 port valve as Karl illustrated?
lookforjoe
True Classic
Interesting. The vacuum operated heater valves used by Volvo on older models do cut off flow entirely (whether or not OEM brands, I've used a variety). With the valve closed, the heater hoses are ambient temp. Of course, the rubber lip on the flap does where out over the years. Now that I've said that, I'm sure the 740 one I have in use on my X1/9 will leak
Dr.Jeff
True Classic
Ya, I was referring to the bypass/4-port valve shown by Karl. Otherwise I agree with you, no significant heat transfer typically. Which is why I will stick with a standard (non-bypass) valve if I don't move it to the engine bay.
With the ones I've used (VW source) I haven't found that to be the case. In fact the complete lack of flow throughout the majority of the year causes heater core rot issues.
kmead
Old enough to know better
Good day all.
It was a beautiful day here in West Michigan and I figured I should spend it with the X out in the driveway in the sun and with me in a variety of contorted positions reaching under the HVAC box of my 87 X with AC.
I had begun trying to get the heater control valve out last fall and had stopped after munging up my hands on all the sharp edges. As some of you know the valve is mounted to the middle section of the box assembly to a bracket riveted to the plastic and then affixed to the bracket by two downward facing screw heads (thankfully).
Last fall I had given up on getting the screws out and was thinking I would fatigue the bracket by moving it back and forth. and remove the whole mess. Yes an a’hole move which I am I glad I eventually abandoned. Today, I found I could reach the screw heads by reaching under the heater box and with a couple of tricky Philips bit holders eventually coaxed both fasteners out of the heater core. Which took several hours with breaks. Don’t try this at home.
So once I got it out there were two surprises. The first was that it seems like the valve was still operable. Which is great, sort of. The second was the the valve was not brass but was in fact a plastic valve made by Gurtner, which I believe is a French company, it has no other identifying marks or part numbers. It works precisely like the brass version but is conceivably serviceable and relies on the mounting bracket to hold an O ring into the valve base. General pictures of it attached. If anyone wants more detail let me know. This was apparently the OE valve at the time of production so there is now another variation we might be able to find.
I will be installing an after market one I bought previously to replace it. I am going to let it float using the hoses and have the actuating cable attached to a bracket I will make using the clamping clip from the OE installation. There is no way I am going to try to reinstall it the way Fiat intended, I don’t think it will pose much of a problem over time. Images of the original and the replacement below, the bracket is yet to be designed but I know how I will make it. I am more interested in serviceability than orginality in this case.
I also ran across an ebay listing for a metal valve which looks like a good substitute for the Fiat one which comes from a Suzuki Samurai, Suzuki Manufacturer Part Number: 74710-83020
Anyway, at least I did something. Oh and I finally got the other X out now that the salt from our storm two weeks ago has been washed away by a rainstorm.
It was a beautiful day here in West Michigan and I figured I should spend it with the X out in the driveway in the sun and with me in a variety of contorted positions reaching under the HVAC box of my 87 X with AC.
I had begun trying to get the heater control valve out last fall and had stopped after munging up my hands on all the sharp edges. As some of you know the valve is mounted to the middle section of the box assembly to a bracket riveted to the plastic and then affixed to the bracket by two downward facing screw heads (thankfully).
Last fall I had given up on getting the screws out and was thinking I would fatigue the bracket by moving it back and forth. and remove the whole mess. Yes an a’hole move which I am I glad I eventually abandoned. Today, I found I could reach the screw heads by reaching under the heater box and with a couple of tricky Philips bit holders eventually coaxed both fasteners out of the heater core. Which took several hours with breaks. Don’t try this at home.
So once I got it out there were two surprises. The first was that it seems like the valve was still operable. Which is great, sort of. The second was the the valve was not brass but was in fact a plastic valve made by Gurtner, which I believe is a French company, it has no other identifying marks or part numbers. It works precisely like the brass version but is conceivably serviceable and relies on the mounting bracket to hold an O ring into the valve base. General pictures of it attached. If anyone wants more detail let me know. This was apparently the OE valve at the time of production so there is now another variation we might be able to find.
I will be installing an after market one I bought previously to replace it. I am going to let it float using the hoses and have the actuating cable attached to a bracket I will make using the clamping clip from the OE installation. There is no way I am going to try to reinstall it the way Fiat intended, I don’t think it will pose much of a problem over time. Images of the original and the replacement below, the bracket is yet to be designed but I know how I will make it. I am more interested in serviceability than orginality in this case.
I also ran across an ebay listing for a metal valve which looks like a good substitute for the Fiat one which comes from a Suzuki Samurai, Suzuki Manufacturer Part Number: 74710-83020
Anyway, at least I did something. Oh and I finally got the other X out now that the salt from our storm two weeks ago has been washed away by a rainstorm.
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