Well this doesn't directly answer your question but why not consider going the extra distance and remove the line returning from the radiator cooler as it enters the transmission? That way you are also flushing out the fluid not normally removed when you do it by disconnecting the line from the upper radiator connection. Like you I wasn't sure how to remove the clip from the upper radiator connection and I think you may also have to have an 'O' ring spare just in case the old one becomes U/S during the procedure.

Despite the impressions you may have gleaned from bay13 and this site, it is not that much more difficult to do. The 1/2 inch I.D. hose fits neatly over the line after the union nut is pulled back.

Follow the procedure in the Haynes manual, apart from having to remove the splash guard under the radiator which I found an unnecessary step. From experience is is easy.

Cheers,

Phil

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'98 N/A S70 136,000 Klm