Booster vacuum lines and union

[Honger]

So the old vacuum line for my brake booster was pretty shot. In an effort to ensure I don't have vacuum leaks I'm replacing all vacuum lines. A few questions.

Is air hose an acceptable substitute for a vacuum line? I'd like to use this hose I picked up in the industrial area rather than ordering the replacement.

Also, the union fitting from the vacuum line to my manifold was quite loose... Was able to easily remove it one handed. This little Union fitting has the five fins on it and screws into the manifold. When reinstalling this fitting should I put any locktite on the threads?

 

[lostmarbles]

....Is air hose an acceptable substitute for a vacuum line? I'd like to use this hose I picked up in the industrial area rather than ordering the replacement....

So long as the walls are stiff enough (to resist collapsing) you should be OK.

Here you can see I'm using 400psi-rated hose for vacuum (and fuel hose for carrying hot oil too):

I like to see fabric reinforcing inside the rubber when I cut the hose. But in fact, a small-bore hose doesn't need to be particularly strong to resist collapsing inwards (unlike large-dia air intake hoses between air cleaner and intake manifold). So really my 400psi hose in the photo is overkill.

..Also, the union fitting from the vacuum line to my manifold was quite loose... Was able to easily remove it one handed. This little Union fitting has the five fins on it and screws into the manifold. When reinstalling this fitting should I put any locktite on the threads?..

Sorry but I'm not sure exactly what you're referring to here.. So I'll leave this for someone else...

 

[Honger]

So long as the walls are stiff enough (to resist collapsing) you should be OK.

Here you can see I'm using 400psi-rated hose for vacuum (and fuel hose for carrying hot oil too):
View attachment 1060225

I like to see fabric reinforcing inside the rubber when I cut the hose. But in fact, a small-bore hose doesn't need to be particularly strong to resist collapsing inwards (unlike large-dia air intake hoses between air cleaner and intake manifold). So really my 400psi hose in the photo is overkill.

Thanks a bunch for the input... lines up with the assumptions I was making as well. I snagged some air hose, and it has fabric woven into the rubber, and I'm confident it won't collapse.

For the smaller bore vacuum hose from the carb-to-dizzy I'm going to try some fuel hose with the same internal diameter. Again, I assumed that the smaller size will naturally be more resistance to collapse.

Sorry but I'm not sure exactly what you're referring to here.. So I'll leave this for someone else...

The union fitting (Toyota's name for it) is the union between the intake manifold and the vacuum hose to the booster. Here's a pic...

I'm assuming this part doesn't really do anything special except dissipate heat before connecting to the rubber hose. I'll put some anti-sieze on it, tighten it back down into the manifold, and check it in a few weeks to see if it loosened itself up.

 

[lostmarbles]

...The union fitting (Toyota's name for it) is the union between the intake manifold and the vacuum hose to the booster. Here's a pic...

I'm assuming this part doesn't really do anything special except dissipate heat before connecting to the rubber hose. I'll put some anti-sieze on it, tighten it back down into the manifold, and check it in a few weeks to see if it loosened itself up.

Wow.. Never seen one of those before. Nice!

If the female thread is metal too, and there's risk of it coming loose, then blue loctite would probably be a good idea IMO. (It'll both "stop it from loosening" and "seal the thread".)

(Often using Loctite is preferable to "adding more torque" when you want to stop something from coming loose.)