All of the gear boxes on the FJ Cruiser have breather caps on them. The breather cap allows the gear box to release pressure and prevent pressure from being applied to the seals. The breathers can present a problem when submerged.

Fitting on Differential

When a gear box is cooled quickly by water the pressure drops and it attempts to draw air in through the breather cap. The caps are designed to seal when suction is applied but it can be held open by a small grain of dirt. If the breather is open when submerged in water the gear box will draw water in and contaminate the gear oil.

Vacuum T

To prevent the gear box from drawing water in it is best to relocate the breather intake to above the expected water level.  On the 2010 FJ Cruiser all the front gear box breathers are already mounted high. However, the rear differential and e-locker breathers need to be relocated. For my relocation I used about 4′ of 1/4″ fuel line, a small fuel filter, a vacuum line t, a fitting for the differential and a number of  clamps.

Breather Cap Installed

I used the original breather cap as the cap to my breather extension. I placed the breather up by the fuel fill. The T connector is used to connect the e-locker breather to the relocation line.

T Connector Installed

The installation took an hour and cost about $17.00.

Installed tubing ready to be located with Fuel Fill