Subaru's 'hillholder' thingy

I used to work on cars and still do on my own car. But I never worked on one of these. How do these things work? They can’t be using the brakes because they only stop you from rolling backward. Is it something inside the transaxle?

[rant]
BTW, I think these things are totally gay. If you can’t take off uphill with a standard you’re an uncoordinated wussy and should have ‘AUTOMATIC TRANNY ONLY’ tattooed on your forehead…
[/rant]

The master cylinders for the clutch and brake are connected, and there is a check valve that only works if the car is tilted more than a certain number of degrees from horizontal.

In this case, when you hit the brake and clutch at the same time, the brake pressure is kept in the line by the check valve.

When you relase the clutch, the check valve opens, and the brakes release.

I had one for several years, handy on some of the hills around here, but not required.

Ugly

Is that the same way the old Studebaker Hillholder Clutch worked?

You might want to reconsider your use of the word “gay” around here.

I’m politically incorrect. So sue me.