trying to solve solve soft brake pedal since weekend

[Paisano]

I going to pick up 1/4 inch NPT air coupler from Auto Zone today.
I don't know if this is the right one.

I saw this part description online also: 3/8 inch female NPT with 1/4 inch body flow
This seems to make more sense.

The quick coupler I need is already mounted on my air compressor. I just need a second one for the Mityvac.

Can't really screw the hose right in to the mityvac fitting. Air hose fitting doesn't rotate.

I'll follow up

 

[pentode]

I going to pick up 1/4 inch NPT air coupler from Auto Zone today.
I don't know if this is the right one.

I saw this part description online also: 3/8 inch female NPT with 1/4 inch body flow
This seems to make more sense.

The quick coupler I need is already mounted on my air compressor. I just need a second one for the Mityvac.

Assuming I'm following you, just considering the tool end of the hose, what I was suggesting was removing the quick connect from the Mityvac and screwing the hose directly in. In Curious Hound's photo it does look like the quick connect is removable.

Don't want to mess up your plan, just trying to save you a trip.

 

[Curious Hound]

In Curious Hound's photo it does look like the quick connect is removable.

He may have a different model of MityVac system. They make a bunch of products.

 

[pentode]

Very good point, I would just check before I spent money on an uber. I'm just trying to be cheap here.

 

[Paisano]

I cannot screw the air hose fitting onto the mityvac fitting. Yes it would fit. But the air hose fitting does not rotate to screw in.
I have not taken Uber ride yet. The AutoZone is within walking distance. I think what I need is:

quick connect coupling
3/8 inch female thread
1/4 body flow push to connect (no threads)

But I'll find out when I pick up the one from Auto Zone

 

[pentode]

I cannot screw the air hose fitting onto the mityvac fitting. Yes it would fit. But the air hose fitting does not rotate to screw in.
I have not taken Uber ride yet. The AutoZone is within walking distance. I think what I need is:

quick connect coupling
3/8 inch female thread
1/4 body flow push to connect (no threads)

But I'll find out when I pick up the one from Auto Zone

Forgive me because I'm terrible at visualizing things, but couldn't you screw the tool onto the hose? Or rotate the whole hose?

I'll stop offering advice now, hope it works out well for you.