Another heater tap question

[n/a]

Hello Everyone
I noticed that my car's heater is on all of the time and after reading the posts about problems with heater taps I prised the inspection plug off the firewall to take a look. The tap certainly appears to be in good working order and turns smoothly when operated by the lower red slider on the left side of the heater controls. The lower right side heat control moves a little too easily and appears to do nothing although the top control that opens the cold air vent works fine. Any suggestions as to why it still lets hot air into the cabin?
Thanks

Mark

1965 230 SL

[Tom]

Mark,

The lower left right slider may move smoothly but may not completely close the valve in the heater box.  There is a ball joint (similar to the ends of the linkages in the engine compartment) that is adjustable like the engine linkages.  Ensure that the linkage engages such that the valve in the heater box is 100% closed.  This is done by removing the inspection plug, separating the linkage and determining if the valve will move past where the linkage would have stopped.  If so, adjust the linkage (consider replacing the linkage-it is probably rusted).

Additional foil backed insulation under the transmission tunnel carpet and the floor board carpet helps keep the heat down.

Best,

Tom

[Naj ✝︎]

Mark,
The left heater control operates the hot air flap for the left side of the cabin which then operates the valve for warm water to flow thru the matrix. The right lever operates only the flap for the right side of the cabin and therefore slides a lot easier.
While the valve stops the flow of water thru the matrix, there is always warm water in the matrix and if the right flap is open it will allow air to flow thru it and some warm air will come thru.  With worn seals there is always some warm air coming thru even with both hot air flaps fully shut.
By removing the air scoop and cold air flap you can check if the hot air flaps shut fully and that seals are okay.
Also a good opportunity to clean out the air box and clear out the water drains.
Now there's a project!!
naj

naj
'Kloines Scheisserle'
65 230SL
68 280SL

[hands_aus]

Hey Naj,
It seems strange to have the hot water in the core all the time. I think if the heater hoses in the engine bay were reversed that would solve the problem.
Very un-original though, but it wouldn't look any more untidy than the rest of the engine bay given all the tubes and hoses etc.

Bob(Brisbane,Australia)

[Naj ✝︎]

Bob,
Worth a try you reckon??
Does not get that hot in UK so I've ignored it but in Australia...
naj
 

naj
'Kloines Scheisserle'
65 230SL
68 280SL

[n/a]

Thanks Naj and Bob
I'll pull the air scoop and cold air flap off next weekend and take a good look. I have a feeling that this is why the previous owner had air conditioning installed - to avoid delving into the intricacies of the heating system! By the way, I've just had the front brake calipers upgraded to the later two piston system and the braking is far superior. A lot cheaper to service as well.
Regards
Mark

1965 230 SL

[hands_aus]

This is a follow on from MarkRs’ topic about heater cores.

I have extracted the heater core valve after long arduous hours of worrying about the broken screw in the top of the valve.

I drilled a pilot hole in the centre.

Then, my retired watchmaker friend had a left hand drill bit (I didn’t know they existed but he had lots in his tool boxes) that I used in a tap “T” handle as an 'easy out'.

I went to a bolt shop and the guy GAVE me a 4 x 55mm high tensile bolt to screw into the top of the valve so I could lever it out.

Now that the valve is on my kitchen table I see that there are TWO grooves in it for “O” rings. The one near the top of the valve is a wide and deep groove and the one at the bottom edge is a shallow narrow groove.

When I looked down the throat of the valve body in the heater core I could see a similar groove at the bottom of the shaft to match the bottom groove on the valve itself.

Is this correct?

The reason I ask is that the TOP “O” ring was the only one there. No bottom “O” ring existed.

Both "O" ring grooves had lots of gunk in them.

Someone suggested using high temp grease to lubricate the shaft. Will normal grease work too?

After putting the valve back, I am going to flush out the heater core. I also intend trying the reversal of the heater hoses to keep the hot water out of the core.

I don't think the core will leak because it had water in it before I by passed it in preparation for this job.

Naj, summers here can be as hot as hell....39C on bad days and that is in the shade!

Can I just add more water to the total amount in the cooling system without affecting the concentration of inhibitor/anti-freeze too much?

Of course when I get the valve working I will have to go into the dash and replace the broken red lever with the one I have in the garage but that will be another major project.

Any info greatly appreciated.

Bob(Brisbane,Australia)

[ja17]

If your suffering from heater always on, a temporary fix is to obstruct the heater core water hose so no water passes through it. The heater valve, in theory should do this anyway. Try a glass marble and a hose clamp! Make sure to use a marble too large to go into the metal pipe of the heater. Fix the problem correctly at the first opportunity.

Joe Alexander
Blacklick, Ohio

[hands_aus]

So guys , Sorry my post was soooo long

I really need to know if there are two 'O' rings on the heater core valve or only one.

Also do I need to buy some high temp grease or will normal grease work?

thanks for your help


Bob(Brisbane,Australia)

[Naj ✝︎]

Bob,
Parts book shows only one 'o' ring and the valve on my 230sl did not have the second groove.
naj
 


naj
'Kloines Scheisserle'
65 230SL
68 280SL

[hands_aus]

Hey Naj
Thanks for the info. I am making progress
I sourced an "O" ring today. It is a BS(british standard) 112 size.
I decided not to install a second ring thinking that it would make fitting the valve very difficult.
regards

Bob(Brisbane,Australia)