LucasC Posted January 30, 2018 Report Share Posted January 30, 2018 Hi everybody, I just picked up a 62 M20C. my cabin heat valve is stuck about half way open. I found the cabin fresh air valve on the copilot side on the inside of the firewall but the heat cable does not go there. Any ideas where this valve may be? Quote Link to comment Share on other sites More sharing options...
Hank Posted January 30, 2018 Report Share Posted January 30, 2018 In my 70 C, the heat knob is next to the fresh air knob. Heat comes out under the center pedestal, aimed at knees on both sides; closing them by hand underneath directs the hot air toward the windshield. The actual heat source is a sliding box on the exhaust in front of the firewall--you should be able to follow the cable and trace it through the firewall, and trace the hoses to see where they route from there. Quote Link to comment Share on other sites More sharing options...
takair Posted January 30, 2018 Report Share Posted January 30, 2018 Hank is correct. On the firewall on the right side. You should see it through your oil door. Quote Link to comment Share on other sites More sharing options...
Yetti Posted January 30, 2018 Report Share Posted January 30, 2018 find the muffler follow the scat tube from the muffler shroud to the firewall. Quote Link to comment Share on other sites More sharing options...
LucasC Posted January 30, 2018 Author Report Share Posted January 30, 2018 Thanks guys Quote Link to comment Share on other sites More sharing options...
Guest Posted January 30, 2018 Report Share Posted January 30, 2018 Does this help? Quote Link to comment Share on other sites More sharing options...
carusoam Posted January 30, 2018 Report Share Posted January 30, 2018 There are some changes that occurred over the years... Clarences drawing is pretty helpful to find the airbox on the firewall, the outside air and the hose coming from the heat muff. My 65C had two slide gates for outside air control and hot air control from the muff. The slide gates older than 1965 were made out of rust and didn't like to slide... So... If your push/pull control in the cockpit doesn't give an easy motion, all the way in and all the way out. Chase that cable all the way to the slide gates on the airbox... expect taking the top cowl off is going to reveal the working mechanisms. It will be helpful to hire your favorite mechanic, if unfamiliar... Lubricate wildly... properly.... It was an easy PP thing to take care of... My descriptions can be very inaccurate... it has been a really long time since I worked on my old C... Newer Planes got fancy rotating valves with rubber discs for seals... Best regards, -a- Quote Link to comment Share on other sites More sharing options...
LucasC Posted January 30, 2018 Author Report Share Posted January 30, 2018 On inside firewall airbox there is only 1 slide gate for fresh air and its sticky so im going to lube that also. Drawing looks to only show one slide gate on it also. When i get back out to airport im gonna look for the heat valve. Quote Link to comment Share on other sites More sharing options...
LucasC Posted January 30, 2018 Author Report Share Posted January 30, 2018 Looks like heat valve is #16 on drawing i think. Quote Link to comment Share on other sites More sharing options...
carusoam Posted January 30, 2018 Report Share Posted January 30, 2018 You got it Lucas! Notice the two slide gates look similar in the drawing... There is a cable at the top of each gate. 16 and 17 in the drawing... lubricating all the control cables can help a bit each year... Best regards, -a- Quote Link to comment Share on other sites More sharing options...
LucasC Posted January 30, 2018 Author Report Share Posted January 30, 2018 I found it. Was right in my face all along. Lol. The slide gate is rusted so im sprayed some corrosion x in there and gonna let it soak for a while. I got it to break free but it only shuts 3/4. Was half way out and stuck so making progress. Quote Link to comment Share on other sites More sharing options...
lamont337 Posted January 31, 2018 Report Share Posted January 31, 2018 4 hours ago, LucasC said: I found it. Was right in my face all along. Lol. The slide gate is rusted so im sprayed some corrosion x in there and gonna let it soak for a while. I got it to break free but it only shuts 3/4. Was half way out and stuck so making progress. Oddly enough I removed mine today because the fresh air valve wouldn't open all the way. Cleaned the plates and lubed both cables at both ends. Moving great now. Air box only had 56 years of crud inside. Quote Link to comment Share on other sites More sharing options...
LucasC Posted January 31, 2018 Author Report Share Posted January 31, 2018 2 hours ago, lamont337 said: Oddly enough I removed mine today because the fresh air valve wouldn't open all the way. Cleaned the plates and lubed both cables at both ends. Moving great now. Air box only had 56 years of crud inside. Surprised they lasted this long. Such an easy item to maintain if you take the few minutes to do it. Quote Link to comment Share on other sites More sharing options...
carusoam Posted January 31, 2018 Report Share Posted January 31, 2018 Should last about a year... Come back in 12 months and you will swear you just cleaned it, it looks like it has 50 years of crud keeping it from moving. Best regards, -a- Quote Link to comment Share on other sites More sharing options...
LucasC Posted January 31, 2018 Author Report Share Posted January 31, 2018 Ok so I figured out what the problem is. There was a washer stuck between the slide gate and firewall. Pulled it out and works great. Jeeze. Thanks for all the help. I came over from a Beechcraft musketeer and belonged to a great site with guys like you and it’s great to have the resource. Thanks Quote Link to comment Share on other sites More sharing options...
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