After the fluid from the pump exits the dump, it needs a way to travel from the dump to the cylinder, and that’s the hose. The average hose, at least one of any decent quality, is a stainless steel hose wrapped in about 1/4″ of rubber, and it holds around 5,000 PSI. That’s right, 5,000.

The weak point here is the rubber. Rubber lines tend to flex when the fluid is pushed through them, mainly because of the extreme amount of pressure they’re under. If the hoses rub against a sharp piece of metal, they can wear and then leave the stainless hose exposed. This diminishes the amount of pressure they’re able to hold — and leaves them open to more wear. If a hose punctures, you lose pressure and are therefore SOL. Call a tow truck.

That’s why, when running a line, you have to be careful. I like to run my hoses inside of the frame on most vehicles. That keeps the hose from dragging on the ground, and it protects the hose from sharp objects. I sometimes use zip-ties to hold the line to the frame. They’re easy to use, and they don’t break off like hose clamps with screws. Sounds cheesy, but the fact is they work well. On a car, I run the hoses through the exhaust tunnel. Hydraulic hosing is heat resistent, at least up to temps that even a header would get to, so you can butt the hose right up to the exhaust and have no worries.

Another alternative to rubber line is hardline. Hardline is a steel or stainless steel line that’s bent with a hand bender. I usually run 3/8 .049 hardline. Bending hardline isn’t fun, but on the plus side, you can’t wear through it.

Hardline does have a downside. You can’t plumb it directly to anything that may pivot or have stress on it. This means you don’t want to plumb it directly to a cylinder unless you’re positive the cylinder never moves. Any movement will flex the stiff hardline, and eventually the steel will give, and a pinhole leak will form. Leaks are bad.

The only other disadvantage is cost. Stainless tubing is usually around $2.50 a foot, and you’ll need anywhere from 30-60 feet depending on the complexity of the system, and how much you’re hardlining. Plus there’s the cost of tools. This is why most systems have rubber hoses — they come with the kits.

Follow up tomorrow with step 8, switches.

This entry was posted on Thursday, February 7th, 2008 at 11:58 am and is filed under Custom Ride. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.