Line Lock
icman95, I would be careful with the use of a line lock for a longer period of time.
Before I installed the Mico lock I checked with a performance shop around here looking for a cheaper alternative. When I told the supplier what I wanted to do with it he said a line lock was designed to hold for a short time. I don't know how a line lock works. I assume a solenoid holds a valve against the brake fluid so when you release the line lock the release is instantanious.
The remote electric Mico lock I refered to in the previous post is similar to the lever lock in that you can set the switch before or while you have the brake pushed down. To release the electric unit you turn the switch off and then push the brake in again to get enough pressure to release the check valve. I had that unit on a 91 Chev 1 ton with a 454. The brake line ran close enough to the exhaust that if I let the truck idle with the Mico lock on, the brake fluid would heat up and expand and I could not release the valve in the remote unit. I had to crawl under the truck and open the bleeder to take some pressure off. I learned to set the brake so it would just hold the truck and trailer.
Stan