Here is Eric/Deb Faires suggestion. On our 92 Angola, we had a leak from the fitting at the actual gauge on the dash. Where the gauge was fastened to the air line, that's where we had a leak. Replaced the little fitting, that leak ended. Would surprise me that both gauge fittings/connections would go at same time, but might be worth a look. Was fun experience removing the dash to look behind it to see lots of wires for the first time.

Eric and Debbie Faires
Huntsville, TN