i JUST fixed the sagging rear in the 83 TD I have. I never saw any leaks in the rear, but the front was covered with oil and such. I rebuilt the low and high pressure hoses, and flushed the fluid. it's been holding level ever since (2 days so far) and I've not lost any fluid. I set it about 1" above the high line, and it's held there for 2 days.
I've noticed the 87 uses crimped connections on the high pressure lines... bummer. so in order to rebuild, you have to cut them out, or order new lines from source. or buy replacement fittings that are rebuild-able...