“A circuit test pressurizes the transmission with oil, not only to check the integrity of the seals, but to check the integrity of all the parts of the transmission,” says Craig Leuck, JASPER Transmission Division Manager.

 

A recent example of a pressure-related failure found through circuit testing is the discovery of porosity in aluminum castings. The included image shows the accumulator housing of a GM front-wheel drive transmission with pores found in the aluminum when it was originally cast. “These pores allowed fluid to bleed from one side to the other, which caused the part to fail the circuit test,” says Leuck. “This circuit test is another value added to our transmission product line in an effort to improve the quality at no extra cost to the customer.”