Defender TD5 swivel suddenly leaks oil

Started the job of replacing front discs and calipers my 2001 Defender today as soon as I removed one of the bolts that holds the flexible brake pipe bracket to the top of the swivel housing oil leaked from the bottom of the swivel, between the swivel seal and the swivel itself. The same thing happened on the other side and I assume taking the bolt out allowed some air into the swivel housing allowing the oil to drain. This is really odd because there was no sign of leakage at all swivel seals previously and swivels themselves are in good order with no pitting or corrosion. Has anybody experienced this? I'm tempted to put one shot grease into the swivel and see what happens as there was no previous sign of leakage. It's the newer style of swivel housing on this vehicle and only has a fill plug no level or drain plugs so I thought it should have had grease in it from the start. Any suggestions welcome

When you tighten the bolts up does the leak go away ?

Hi, thanks for responding. I havent tried that but the oil stooped draining after a while so I assume there was very little in there anyway. The fact that oil can escape I assume means that the seals are not good but I cant understand why there was no sign of leaking before, really confusing!!

Isn't the brake pipe bracket held by the bolt in the top swivel pin?
If you free it off then the swivel will move and not sit in the center of the seal possibly leaving a slight gap between seal and swivel, and allowing the oil to leak.

The housing drops a bit when you release the top bolts and oil/swivel grease comes out, to avoid in future just place an extra jack/support under the housing. Not leaking before so just refill, this is done with the swivel at full lock for clearance at the filler hole.

Excellent responses, thanks! Yes, that makes sense, sounds like the seals are fine then, that's quite a relief, didn't fancy another job