Hi, I have a couple perplexing problems with my 95 D1. I don't think they are unique to land rovers, but I've never had these problems with any other vehicle.
First is : where is my brake fluid going? over the past couple years I've had to keep adding brake fluid to the master cylinder, but I find no leaks anywhere. not at the wheel cylindrers, not at the mc, not at any lines or fittings. Where the heck is the fluid going? brakes work fine, don't ever need to be bled. I've probably used a quart in the past 2 years. there shoud be a big puddle of brake fluid somewhere by now!
Second: battery dies if vehicle sits for more than 3 days. I've done all the checks to find a power drain, replaced the alternator, checked for any lights staying on, etc. Without starting the engine, I check the battery after 1 day sitting, fully charged, after 2 days sitting, fully charged. 3 days; fully charged, then about the 4th day it will be flat. It's like something is getting turned on automaticaly draining the battery, but when I recharge it and check all systems, I find nothng amiss. If I drive it every 2 or 3 days, no problems, but sitting for 4 days; dead battery.

 

Both my 94 and 96 can go many weeks without needing a recharge. Maybe use an ammeter to find out where the current is going, start at the engine bay fuse box and follow the current downstream. Simple to remove the fuse and jumper the ammeter in its place. Could also scan the fuses with an infrared camera, if available. The fuses with current flow will be slightly warmer than the rest, after sitting for a long time.

Alternative is to disconnect the battery when you park for longer times. I do that with the 96 since it is mostly a winter vehicle.

 

It's possible that you have a constant drain and the battery discharge behaviour is non linear. In other words it holds relatively high charge for 3 days and then the discharge curve gets very steep.

I can't think of any systems that would turn on after 3 days.

If you've already chased the drain as best you can / according to JohnZo's recommendation, consider getting or building a voltage / amperage data logger and putting it on the system on day 3. Maybe you'll see something magically turn on after 72 hours

 

Rear of MC can leak into the Brake Booster, and the F/R valve can seep down on the inner fender and when driving blow back and hardly be noticeable.

 

thanx. i'll check that out

 

thanks for the tips.