[jarni75]

Good day to all you 107 fans out there!

I have a 1971 350SL with AC1 (according to EG) and have some problems with it...:

1. the ac panel is different than the AC 1 on EG (attached picture)
2. I get hot air at my feet all the time...
3. My AC is not working at all... I guess I should have it filled up with gas...

For the last week I am reading through EG and this precious forum and I do not seem to understand how to fix my problems... I thought that I will see the vacuum valve when I take the glovebox element out, but there is none... only two on the vacuum valves on firewall in the engine bay...


Can someone please point me to the right post where I can read how my heating and cooling works... since I am not able to find these valves on the firewall anywhere...

I am sorry for the huuuge pictures but I cannot make the smaller or either turn them around... but obviously I cannot post with pictures...

Thanks in advance for any responce!
J

 

[jarni75]

attaching pictures...

 

[cushjbc]

Jarni,

Look at this for your heating system. If you have heat all the time, the valve (sometimes called a faucet) on the firewall is not closing properly.

 

[jarni75]

Jarni,

Look at this for your heating system. If you have heat all the time, the valve (sometimes called a faucet) on the firewall is not closing properly.

Thank you very much for this... Are you talking about part Nr. 1, 2, 3, 4 or 5?

Best regards, J

 

[Hillingdoner]

Cushjbc (hi by the way, get caught in any snow this weekend?) is talking about part 4 & 5.

The way the valve works is that part 4 has vacuum to it and pulls the actuating arm on part 5 to close off the valve. When the part 4 is faulty or you have lost vacuum to the line to part 4 then the valve arm will not actuate on part 5 and it will leave the valve open so that coolant is flowing all the time. This causes heat in the interior of the car all the time.

 

[Hillingdoner]

Just went through this on mine heat wise by the way. Same basic system. Took the mighty vac and tried to pull a vacuum on the vacuum pod on the heater valve. Nothing doing. Vac valve was bad on mine. Replaced it and now the the coolant flow is shut off so that I no longer have the blast furnace going all the time in the interior.

As far as the picture of your panel. Looks a little different than I'm used to, but should be basically the same. Looks like lower left knob is your AC temp control to adjust the amount of cooling from the AC. Right knob looks like the blower speed control. The upper knob unsure, but on my mate's 450 he has a cruise control knob on the panel so maybe your panel is similar. I'm sure those more in the know will chime in.

I imagine the levers probably work about the same. You can look at the owner's manual section on this site for an earlier car and get basically the gist of how they work.
https://www.startekinfo.com/StarTek/outside/11883/?requestedDocId=11883

 

[rowdie]

Your control valves seem to have the wrong vacuum connections.

Parts 4 and 5 are no longer available. They can be replaced by the later one piece valve with one vacuum line.

 

[jarni75]

I went to see how my system on the firewall looks like and I saw that I do not have parts 4 and 5 anywhere near ... Is it possible that they are somewhere else

Sorry for a HUUUGE picture...

J

 

[rowdie]

I don't see a picture. Did you see a black plastic valve like this one. MERCEDES-BENZ OEM HVAC Heater Control Valve 107-830-05-84 1078300584 | eBay

 

[jarni75]

valve

I don't see a picture. Did you see a black plastic valve like this one. MERCEDES-BENZ OEM HVAC Heater Control Valve 107-830-05-84 1078300584 | eBay

No I do not have this kind of valve anywhere.. where should it be? On the firewall ? My firewall looks like this...

 

[jarni75]

I guess it should be on the spor where the black hose enters the firewall... that is hot water from the engine right?

Thanx

 

[Hillingdoner]

Here is a picture snagged from a UK site on a 350sl. I've circled the heater valve with vacuum pod on it. Got anything looks similar?

Heater hose should run to it and then you should see a (perhaps still metal) bit it goes to and then a vacuum pod on the side of it.

 

[rowdie]

Other side of the firewall. Left side of the car. Right side if looking from the front.

Is this a right or left hand drive? A more specific location would help.

 

[Hillingdoner]

Posted at the same moment :grin

If there is not valve further down the hose towards the engine then pull that cover plate where the hose goes in. Large piece on top of the bulk head there that is painted silver.

See if anything inside there.

 

[jarni75]

Other side of the firewall. Left side of the car. Right side if looking from the front.

Is this a right or left hand drive? A more specific location would help.

I live in Europe and this is LHD...

Does anyone know of a VIN identifier for 1971 350SL... By the documents it is a 1971, but I do not know for sure... and would really like to check...

 

[jarni75]

Posted at the same moment :grin

If there is not valve further down the hose towards the engine then pull that cover plate where the hose goes in. Large piece on top of the bulk head there that is painted silver.

See if anything inside there.

I will do this tomorrow... if there is nothing in there then I have no water heater valve and it is logical that the heat is always on?!? Because a valve is missing...

Thanx

 

[masand68]

I guess it should be on the spor where the black hose enters the firewall... that is hot water from the engine right?

Thanx

In your picture the black hose going into the firewall is for the heat. it looks like the valve has been removed and bypassed . You can see the screw holes and the cleaner spot on the firewall where it was mounted.


Sent from my SM-T350 using Tapatalk

 

[rowdie]

I live in Europe ...

Obviously. That is in your profile. It is like saying USA or Canada.

I missed the picture because I was posting. I agree someone eliminated the control valve.

 

[Aussiemerc]

As long as the valve is mounted just forward of the firewall you're good to go. The vacuum line runs to the bottom of lever 1 (left) by feeding it through the firewall on the left side of the cabin (looking forward) The other vac line nipple on lever 1 is to run it to lever 4. The water valve is default open so it has to be shut by vacuum to stop heat.

You have to remove the transmission carpet and the bolster under the dash to see everything.

 

[Aussiemerc]

BTW the left switch is normally fan speed and the right one is aircon on/off and temp setting.