I think you're thinking of a proportioning valve, and they're used on many more cars than just the "computer controlled" other wise, you'd be getting the rear wheels locking up all of the time. Under even moderate breaking a lot of weight is shifted off of the rear and on to the front. If equal pressure is delivered to all four brakes (simultaneously even... some proportioning valves include a fraction-of-a-second delay) it will result in the rear wheels locking in the most awkward of manners. Granted, the Delorean rear-end has some, um, ballast, and I'm not sure how its system is proportioned front-rear, but I can assure you that many cars (especially light, FWD configurations) get proportioned regardless of whether or not they have computer intervention. Josh Keady (no D, but I like cars...) http://www.wizzards.net/keady/ on 7/31/02 6:40 PM, basfe25 at dmcman73@xxxx wrote: snip > Pressure > regulators are used on computer controlled brake systems...not fully > manual ones like the Delorean. > snip