Heater Valve - Heat On/Off ?

[bpossel]

Hello All,

Please look at the attached pic.  Do I have the heat on/off direction correct on the pic or is it the other way?

Thanks!
Bob

Download Attachment: valve1.jpg
16.93 KB

bpossel  (Memphis, TN.)
'71 280SL  /  '97 E320

[al_lieffring]

Bob

You've got it backwards.
It could be a Deutch/English problem.
Auf means closed (in plumbing auf means off but on electricals auf means on)

are you more confused now?

Al  :O)

113-042-10-014715
built 11 Jan 66
904/396 blue, Ivory Tex
condition- rust bucket

[DavidAPease]

Bob,

My memory from doing this job is that the top of the round valve (as I will call the part that actually turns to open and close the water passage) is square, and that you can put the arm on the top of it in any of four directions.  Thus, I believe that it is impossible to answer your question definitively from the attached photo.  (If the arm has never been removed, there may be an answer, which I guess Al has supplied.)

When I redid my valve, I made a mark on the top of the valve directly above the opening in its side.  When that mark points towards the front of the car (i.e., is lined up with the water inlet pipe), the heat is on (so to speak...).  Make sure that you reattach the arm and its linkage such that the interior heater lever is in the "on" position, and you're set.  

Of course, this requires you to pull the round valve out to mark it.  See posts from folks like Arthur Dalton about how to do this, and the pitfalls involved (including the possibility of dropping the valve into the heater core).  The short advice is: Have a long screw threaded to match the little screw shown in your photo, and use it to pull the valve; never let go of it, and putting a very large washer on it will keep it from dropping down when you slip; stuff rags around where you're working so that "stuff" doesn't end up in the black hole adjacent to the heater core.

It's really not too hard, just take some care.  Good luck!

-David Pease
'66 French 230SL

[bpossel]

Hello Al, David!

Thanks for the information!  It helps!
Will be replacing the heater valve o-ring this weekend, and just wanted to understand the way the valve works.

I will mark, as you suggested, prior to removal.  Will take some pics for the website and post.

Regards from Memphis,
Bob

bpossel  (Memphis, TN.)
'71 280SL  /  '97 E320

[DavidAPease]

Hi, Bob,

Actually, I was not suggesting that you mark the valve prior to removal.  

The way the valve works is that the round valve is a hollow cylinder with a hole in the side (like a tin can with the bottom cut off and a hole punched in one side).  When that hole lines up with the water inlet pipe, the water flows into the hole and out the bottom, and you have heat.  When the hole is turned away, there is no flow and no heat.

There is one other thing you need to understand about assembling the valve: there is a "limiter" (for lack of a better name) setup that controls how far the valve can rotate in either direction.  It is the dark grey piece of metal that is at about 4-6 o'clock in your photo; that piece of metal rotates within a slot that limits its movement.

So, I was suggesting that you remove the valve, then make a mark above the center of the opening in it.  After replacing the o-ring, reinsert the valve in the open (heat) position, but don't hook it up.  Move the dash heater lever and see how the linkage moves, then set the dash lever to "heat".  Orient the limiter and the arm so that when you move the dash lever to "no heat" it will move the valve towards the other end of its travel, and reassemble everything.  (Remember that the arm can be attached to the valve in any of 4 positions; also, because of the limiter, it is impossible to remove the valve without first removing the screw, arm, and limiter.)

I hope this makes some sense.

-David Pease
'66 French 230SL

[66andBlue]

Bob,
I was able to check my heater core (since is still not installed and sitting on the bench) and your picture is indeed correct.
[Sorry, Al].
Moving the lever in the direction to the engine opens the valve.

Alfred
1966 blue 230SL automatic

[ted280sl]

Bob,
  Even if you have it properly installed the connecting rods are adjustable for a reason. The only way I found to make sure that it is installed properly and adjusted was to connect a water hose to one end of the heater core and adjust the linkage until there was no water coming out when the valve was shut. Mine was improperly adjusted so that even when I had installed it properly there was still water flowing through the heater core and heating the passenger compartment. My car was a really "hot ride" in the summer. Now it is very "cool". I really do apologize for that comment.
Ted
'69 280SL 4 Speed

[al_lieffring]

I will stand by my previous statement.
When the red drivers side lever is slid to the left it pushes the cable to the temp. controll door, the cable lever is on the bottom of the door so the door swings down to direct the fresh air through the heater core, a second arm that operates the valve is above the door so when the temp. door swings down to the heat position it pulls the linkage on the valve lever to the open (rear) position.

There are 31 wrong ways to assemble the valve (the limit plate can be installed upside down) and only 1 right way.

Al

113-042-10-014715
built 11 Jan 66
904/396 blue, Ivory Tex
condition- rust bucket

[DavidAPease]

Hi, Al,

I agree with you, IF the valve has been assembled the (1 chance in 32) right way.  However, in my case, the valve had once been installed 90 degrees off, and so rotating the valve to the rear closed it.  Of course, this meant that when the door directed heat through the heater core the core was cool, but when the door let fresh air in the core was hot.  (The only way to get any heat at all was to turn the driver's control to "cool" and the passenger's to "hot", and get some heat on the passenger's side.)  Obviously, once I figured out the problem I fixed it.  

However, this is why I say that you cannot tell from a photo of a disconnected arm how the valve is actually oriented.  Perhaps Alfred's valve is suffering a similar mis-assembly?

-David Pease
'66 French 230SL

[bpossel]

Anyone else have any experience with this one?  I am going to pull my valve and replace the o-ring this weekend.  Will take pics, and post.  Would be nice to know what others think...
  Thanks!
Bob

bpossel  (Memphis, TN.)
'71 280SL  /  '97 E320

[bpossel]

Hi All, does this make sense :oops: ?

“Heat on” driver’s side = upper left lever in cabin slid to the left.

With the lever slid to the left, it pushes the cable forward, extending it into the air dam area(towards the engine.)

As cable is slid forward, towards the engine, it causes the air flap (dish) to close (sit horizontal).

As air flap (dish) is closed, it draws the metal link rod back towards the driver (away from the engine).

As the metal link rod is drawn back towards the driver (away from the engine) it moves the heater valve lever (pic shown in my original post) also back towards the driver (away from the engine).

So in summary, with heat on, the heater valve lever is drawn back towards the driver (rear of car).  This would indicate that my diagram (pic in my original post) is backwards….  Correct?

Bob


bpossel  (Memphis, TN.)
'71 280SL  /  '97 E320

[ted280sl]

Bob,
  I worked on this once going in only through the large rubber grommet on the firewall. It can be done that way but, I found it much easier to work in the area by removing the cowling over the air induction. It csan be removed rather easily. The chrome grill is held in with a few screws. The cowling itself has a few screws in the back which need to be loosened, two small screws on the outside by the windshield wipers, and two screws on the firewall. This will alow you to remove the cowling. The air flap is now exposed and I believe there are two bolts on each end of the flap. remove the two on either end and the flap can be removed. Disconect it from the cable, remove the air screen and you will have a wonderful unobstructed work area for the heating system.
Have fun,
Ted
'69 280SL

[Mike]

Bob, I checked my valve this morning and confirmed my recollection.  That is, your picture had it correct, i.e. with the arm of the valve pulled all the way back to the rear of the car, the heat is off.  The linkage on my heater flaps broke off so I turn my heat off in the summer and on in the winter.  I still have it set on the summer setting and the valve is all the way back, just like your picture.

Mike

[DavidAPease]

Hi, again, Bob,

Yes, you are exactly right (and this is what Al has been saying as well).  

This does not mean that Mike is wrong; I'm sure his car works just as he says.  That is the point I was trying to make from the beginning - you can assemble this valve so that it works in reverse (or even not at all), and unless you attach the linkages and check the operation, you can't tell the difference by looking at it.

-David Pease
'66 French 230SL

[66andBlue]

quote:Originally posted by DavidAPease
 .... Yes, you are exactly right (and this is what Al has been saying as well).  

David and Al,
finally it is sloooowly sinking in!  
I'll have to remember this when I put the core back in.

Alfred
1966 blue 230SL automatic

[bpossel]

Thanks David, Al, Alfred, Mike, Ted!

It has finally soaked in (Thanks to you guys )!  I have attached some pics that I took while renewing the rubber o-ring on the valve.  The one pic shows how I drew and positioned all of the pieces as I removed them, so I could ensure that they were correctly installed again.  But, in reality, what you have been describing is really the way to go on this...

Basically, when re-installing the valve, ensure that the opening on the side of the valve is pointing forward, towards the engine.  This is the "full heat on" position.  Then ensure that the slide control in the car is moved left, and into the full heat position.  Then attach the control arm (adjusting the length as needed) to ensure a nice fit between the two balls, air flap ball and valve arm ball.  The only other important item is the travel limiter plate.  Need to ensure that this is installed so as not to limit the full on/full off stopping points of the valve.

Here’s a pic showing the “puller” I used.  I used a 3 inch (4mm) screw and attached a string to the end and tied the other end to the wiper arm.  This was so that I wouldn’t loose the valve into the core while pulling it out  The longer screw also came in handy to allow me to slide the valve down a bit after removing the small screw, and arm.  You need to slide the valve down (just a hair) to the allow the travel limiter plate to be removed.  Others have suggested to remove the front heater hose and slide a wire into the front of the core opening and into the valve.  This is another option, which I didn’t use.  Bottom line, be very careful not to drop the valve into the core.  There is nothing (no ridge, lip, etc) to stop the valve from falling into the core.  It is basically held in place by the arm and eventual friction of the new rubber o-ring...
Download Attachment: valvepuller2.jpg
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Download Attachment: valvepuller1.jpg
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Here's a pic showing the valve and valve limiter in place.
Download Attachment: valvelimiter.jpg
23.87 KB

Detailed pics of the valve and valve pieces.  The pic of the valve on its side shows how the radiator fluid travels thru the bottom of the valve and then thru the side opening of the valve, allowing fluid to flow thru the heater core.
Download Attachment: valvepieces.jpg
11.23 KB
Download Attachment: valveside.jpg
15.67 KB

In summary, this pic shows the correct heat on/off position (for my car)...
Download Attachment: heat-on-off.jpg
26 KB

Hope this post helps others...
Regards,
Bob

bpossel  (Memphis, TN.)
'71 280SL  /  '97 E320

[tuultyme]

How do you keep a loose valve from falling in while removing the top screw and replacing it with the valve puller. I am sure reinstalling with a new o-ring is not a problem but not sure if the o-ring has detriated?

Bruce; 268Blaugrun(green) 1970 280SL; IL

[bpossel]

Hi Bruce,

I believe it was Alfred who suggested removing the heater hose, at the firewall, and sticking a coat hanger wire into the pipe.  Need to move the valve back and forth to ensure that the coat hanger wire is sticking all the way into the valve.  This should prevent it from falling down.  I didnt need to do this because my valve was still tight in the valve shaft.  I know that I also took a chance by not following Alfred's suggestion.  Overall, not a bad little project at all...
Good Luck!
Bob

bpossel  (Memphis, TN.)
'71 280SL  /  '97 E320

[al_lieffring]

These cars are all old enough that there is one thing you can count on, you are will not be the first person to have taken apart the componets that you will be working on.
So this presents a problem: Putting something back the way it came apart could just be repeating the same mistake that a previous repairman had made.

In the work I do with antique clocks that are 100+ years old the components are almost always incorrectly installed and often that unskilled repairmen will have resorted to bending and mis-adjusting linkages to try to make it work without disassembleng the entire movement a second time.
Since manuals diagraming every time-piece made since Gallileao are rarely available I will look at how all the components in the movement interact with each other and then use that information to determine how the pieces need to be installed to work as originaly designed.
That is why I detailed how the cables and levers work the temp controll flap and valve system. It's nice to be able to come to a sight like this one where there are people who have also done the job that is giving you fits, but it is also nice to be able to stop, take a look and aply some problem solving skills and find a soloution yourself. When I get stumped I am so glad for the help that I have recieved on this forum.

Al  :O)



113-042-10-014715
built 11 Jan 66
904/396 blue, Ivory Tex
condition- rust bucket