Got the same problem 3 months ago with my 97 nissan sentra, my early retired mechanic younger bro did it.

Bumili kami ng pamalit na original O-ring (not repair kit ha) sa Banawe, 4pc ang laman ng isang complete set (sinlaki halos ng 25 centavo coin bawat isa) cost me PHP1800 .

Sabi ng brother ko pag shop mechanic ang gumawa it will cost me around 3-4k pesos, tsambahan pa kung sadyang marunong gumawa ang mekaniko...... Just for sharing.