Heater " O " ring

[n/a]

Anybody out there who can give me advise on how to replace the O ring under the inlet heater valve under the rubber plug in the firewall( +/- 5 cm opening ) ?
It seems to me that the valve control guide sits in the way.


Willy, 230 SL 1967 - 220 SEb 1965

[ted280sl]

Willy,
  The valve control guide is held in place by a screw which must be removed. The operation can be done through the opening in the firewall, and I have done it that way but, it is easier if you also have access by removing the hood cowl. The hood cowl is relatively easy to remove. Te chrome grill is held in by four screws. After the grill is taken out you will need to loosen four screws in the back of the cowl and remove the two screws at the rear corners of the cowl by the windshield wiper arms. You will also need to disconnect the windshield washer hose form the spray head. Now the cowl can be removed. You should have access to the vent flap now. Remove two of the bolts on one side and you can remove the flap. Be careful to slide off the control cable as you remove it. You should now see the intake filter. You will probably want to replace it. I replaced mine with some foberglass air filter material. Once the filter is removed you have significantly improved access to the heater controls and the valve your want to remove.
Best of luck,
Ted
1969 280SL

[n/a]

Ted,

Thanks for your advise, once again. Just today, on the old Yahoo site, there was also a message on this subject.I already removed the top screw an the control cable, than hesitaded for damaging reasons. For all the rest of us, below the procedure from Jim Villers.

HEATER VALVE:

The access is through the top of the firewall. There is a rubber-blanking plug that will pop out to reveal the valve. OK you say .... Now what. By being very careful, you can unscrew the retainer and remove the lever leaving the square post on the valve. Find the longest screw with the same threads to screw into the top of the valve. Cut a short piece of half inch PVC pipe (about a half inch or so) to go over the screw and rest on the outside of the heater valve. Now use a pry or a small claw hammer, resting on the PVC pipe to pull the screw and the valve up and out. Clean everything; replace the two 'O' ring seals and reinstall. It should now rotate smoothly.
You might just get away with trying to twist it but replacing the seals is the way to go.

Jim Villers


Willy, 230 SL 1967 - 220 SEb 1965

[hands_aus]

Hi Willi,
Be aware that by mistake, you can also break off the screw you just screwed into the heater valve.

I did.

I now realize that I am going to have to remove the heater core and take it to a radiator repair workshop for them to dissemble the whole unit and fix the rings.

The screw is broken off about 2 mm below the top of the square section of the valve. It is very inaccessible and in my opinion not able to be removed with the heater core in the car.

I oiled that unit for a month before trying to remove the valve.

If the workshop can't get the screw out of the valve I will have someone put it on a lathe and remove it.

I have a worry about the valve being brass and the broken screw being steel, but at this stage I have put it into my "LONG TERM PROJECTS BASKET"
regards
Bob (Brisbane, Australia)

Bob(Brisbane,Australia)