No wonder my car won't run properly and the brakes only have one assisted operation.
Everything is buried, but with a torch I noticed a crack in the brake servo hose. It was a disgrace when I pulled it out. When replacing, I removed the vacuum tank, the check valve disintegrated.
When I wire brushed and sanded the vacuum tank, that had a small rust hole in it. Expoxied that and painted everything,
Just have to source a check valve - during the Xmas week, thats difficult.

 

As I recall, I put a modern check valve in the line to the tank and used the old valve to connect the pipes to the vacuum tank.

 

Dear me what a mess!

 

On the plus side, you found the problem. I got a proper check valve from Barrett's a while back, but I did not use the proper tank. I used a black plastic sphere taken from a late 70's- early 80's GM car. I also used 3/8 brake line to go across in front of the radiator.