The only way to check for leaks is while the drum is in the case
This drum test tool allows bench checking for drum leaks without having to disassemble and reassemble the transmission for leak testing.
It is often both difficult and time consuming to accurately air check for internal 3-4 drum leakage in vehicles with F4A-EL or G4A-EL transmissions. If the drum leaks, the proper amount of fluid pressure is not applying the clutch piston, resulting in burned clutches, slips or no 2-3 shifts. Currently the only way to air check this drum is while it is in the case. This leakage can often be the result of a poor or cracked weld at the back of the 3-4 drum or worn seals. The weld and seals assist in separating the apply pressure fluid passage from the lubrication circuit. Thus if the weld and seals are not sound, cross-leakage occurs. Sonnax offers a drum test tool for both the F4A-EL and G4A-EL transmissions that will aid in quickly determining if the 3-4 drum leaks.
Contact a Sonnax Parts Distributor.