There are small valves in Tony Hawk's Pro Skater 1 + 2 Downhill Jam course that you need to destroy. These valves are cleverly hidden in the course, causing them to blend into the background to find them a bit of a pain. Here is the breakdown of the five of them to facilitate their search.
All valve locations in Downhill Jam
The first tip is right at the start of the lesson. If you are not looking for it, it is extremely easy to miss it. It is on the pair of pipes to your right, immediately when you start the course. To get it, jump off the ramp, grind one of the pips, and you can drop the valve at the end of them.
The second valve is on a small ramp, quite close to the start. Rather than crushing the pipe on the right side, stay to the left and you should see the ramp with the valve in the middle. The valve is not blocking your path. You destroy it, instead.
The third valve is a bit trickier to find. It's found at the top levels of the map, and if you don't look at it, you might miss it multiple times. The valve sits right in the middle of a pipe. You want to stay on the left side of the course and wait for a big ramp to the side. It should be right before a blowjob. Go to the ramp, jump on the pipe and grind on it to destroy the valve.
The next pipe is on top of a large canister, overlooking a sign that says "Steer Clear". There are two ways to get his valve. The first is to go down the hill, hit the middle ramp with a big jump and get over it. The second is to go around the back and use the rear ramp to get over it. Both methods work.
The last valley is on the side of the wall, just before the end of the course. To catch it, descend to the left side of the map rather than the right where you can see several ramps. The valve is on the side of the wall, right in the middle of the hill, so be sure to catch it with a wall slide or a quick jump before you reach the end.
