View Full Version : valve stem behind engine ?

10-26-2014, 07:19 PM
OK what's the purpose of stem behind the carburetor an has any one
Seen a production car engine that has petcocks like a marine engine

10-26-2014, 07:49 PM
It puzzled me for a while too....
Transmission pressure adjustment port.
Page 6-11 in the service manual.

10-26-2014, 08:18 PM
Thanks for the information, but the engine has drain petcocks on the block like an marine engine that's a puzzle as well ?

10-26-2014, 08:49 PM
What engine do you have in that '60 Squarebird? Is it a 430MEL, by any chance?

10-27-2014, 12:22 AM
I thought it was a high point vent for the transmission. I looked in 6-11 and it says to remove the 1/8" NPT pipe plug at the rear of the trans to install a pressure gauge and adjust the linkage. I did this, but it sure would have been easier to use the stem behind the carburetor. Is this in fact a pressure tap to help in adjusting the linkage?

10-27-2014, 12:56 AM
It is my understanding that Transmission Pressure Test Port was installed for factory use only. Once any adjustments were made at the factory, they just left it in place.

10-27-2014, 01:52 AM
This question comes up from time to time. Here is a picture of the 'test valve':

It should have a cap on it. Some are disconnected at the transmission. Either way, NEVER put air in it. - Dave

10-27-2014, 02:07 PM
It should be 352? I looked at the numbers behind the generater an it's cast. (B9AE6015B) IT has power brakes, power steering, power. Windows, A/C and
Windshield washer allmost forget, four barrel.

10-27-2014, 02:47 PM
An easy way to tell if it is a 352 or a 430MEL engine is to look at the overflow tank! It the ends of it are point towards the left and right fender and it is sitting parallel to the radiator it should be a 352. If the overflow tank ends are point TOWARDS the radiator and the engine firewall, it should be a 430MEL. There are other differences also.