I'm going to be installing an SLP line lock tonight, and while I'm at it going to have the change out a majority of the fluid in the brake system. Should I upgrade from dot3 to 4 or 5...are there any benefits to it? Have to pick up fluid this afternoon just curious what others have done.
Do not use DOT 5, it is silicone based and does not play well with DOT 3, 4v or 5.1. Dot 4 and 5.1 will mix with DOT 3, but generally is thicker. You can pick up DOT 4LV from a Mercedes dealer that will have the higher boiling point characteristics of a DOT 4, but with the lower viscosity of a DOT 3 which plays better with ABS systems. That being said the Motorcraft DOT 3, p/n PM1C has a dry boiling point of 500F, and is very reasonably priced. I sell a bunch to road racers.
That's on my list. I am planning on putting an "arming" switch somewhere out of the way to power switch on knob....that way it doesn't "accidentally" get used on the street.