1965 Coupe Air conditioning Hot Water Vacuum control swtich info and Questions
100_3858.jpg100_3859.jpg100_3860.jpg100_3862.jpgHello Guys,
I think I have posted more this week than my entire previous membership! I was rebuilding the brass vacuum switch. The one that mounts on the top of the heater box and controls the vacuum signal to the hot water valve. The valve at the heater core in the engine compartment. I read many previous posts and read D.r Rebuild's instructions on how to do it. Here are some pictures of the valve apart and some drawings showing the dimensions of the parts. The dimension of the rubber seal is actually the deminsions of the brass parts that it is in contact with so .125" is the od of the shaft the seal is mounted on and .215-.218" is actually the id of the main housing bore. The od of the rubber is actually about .200". The id of the rubber I could not measure so that is why I put down the dimensions I did. The holes in the side of the housing inside the tubes the vacuum hose connects to were plugged up so I slowly worked my way up with number size drill bits untill I met some resistance. I belive that these holes should be #66 or about .033"
Now for the questions. I took everything apart cleaned it good, lubricated the seal wih silicone grease, and put it back together. The plunger now moves very freely but there is no vacuum pased through the switch no matter where the plunger is. I belive that the seal is moving freely on the shaft and therefore blocking the vacuum hole all the time. Is the seal supposed to slide back and forth on the shaft or should it be retained on the shaft towards the end with the button on it? Or is it supposed to be stuck in a certain part of the bore and not move at all? it seems that if it stayed on the shaft towards the plunger end and moved with the shaft but not freely from it, than the switch would work. The question is what makes this happen. do I need a smaller seal? Should the seal be glued to the shaft or into the bore? Please help.
Also, The good Dr. says that he replaced it with an o ring so maybe he can say if it stuck in one place or moves up and down the shaft. I am curious though if an o ring instead of the long seal might affect the operation point of the switch? And one last thing his directions say the the plunger or knob should unscrew from the shaft but mine did not. It was pressed on about .250" I have rebuilt two of these switches and all of the observations above were the same on both of them. I know that earlier switches had different size vacuum hoses, ( I.e. two small ones vs 1 big and 1 little on this switch, so maybe the other style switch is assymbled a little differently. Although the Dr. said that the switch he rebuilt was on his 67.
So I think it should be the same style as on my 65. I would greatly appreciate any comments or Suggestions and once again thanks to Dr. Rebuild for making such a great catalog and selling such great parts.
Thanks again,
Bill
I think I have posted more this week than my entire previous membership! I was rebuilding the brass vacuum switch. The one that mounts on the top of the heater box and controls the vacuum signal to the hot water valve. The valve at the heater core in the engine compartment. I read many previous posts and read D.r Rebuild's instructions on how to do it. Here are some pictures of the valve apart and some drawings showing the dimensions of the parts. The dimension of the rubber seal is actually the deminsions of the brass parts that it is in contact with so .125" is the od of the shaft the seal is mounted on and .215-.218" is actually the id of the main housing bore. The od of the rubber is actually about .200". The id of the rubber I could not measure so that is why I put down the dimensions I did. The holes in the side of the housing inside the tubes the vacuum hose connects to were plugged up so I slowly worked my way up with number size drill bits untill I met some resistance. I belive that these holes should be #66 or about .033"
Now for the questions. I took everything apart cleaned it good, lubricated the seal wih silicone grease, and put it back together. The plunger now moves very freely but there is no vacuum pased through the switch no matter where the plunger is. I belive that the seal is moving freely on the shaft and therefore blocking the vacuum hole all the time. Is the seal supposed to slide back and forth on the shaft or should it be retained on the shaft towards the end with the button on it? Or is it supposed to be stuck in a certain part of the bore and not move at all? it seems that if it stayed on the shaft towards the plunger end and moved with the shaft but not freely from it, than the switch would work. The question is what makes this happen. do I need a smaller seal? Should the seal be glued to the shaft or into the bore? Please help.
Also, The good Dr. says that he replaced it with an o ring so maybe he can say if it stuck in one place or moves up and down the shaft. I am curious though if an o ring instead of the long seal might affect the operation point of the switch? And one last thing his directions say the the plunger or knob should unscrew from the shaft but mine did not. It was pressed on about .250" I have rebuilt two of these switches and all of the observations above were the same on both of them. I know that earlier switches had different size vacuum hoses, ( I.e. two small ones vs 1 big and 1 little on this switch, so maybe the other style switch is assymbled a little differently. Although the Dr. said that the switch he rebuilt was on his 67.
So I think it should be the same style as on my 65. I would greatly appreciate any comments or Suggestions and once again thanks to Dr. Rebuild for making such a great catalog and selling such great parts.
Thanks again,
Bill
Comment