air conditioning expansion valve replacement on 1998 Toyota 4Runner

AC some days it works, some days it doesn't. Have been told need new expansion valve. How hard is it to get to and what should a reasonable repair cost be

Did you have your system Diagnosed and are you sure that it is an expansion valve problem? Because it is very important to have the system properly inspected before you start replacing parts, which can be very expensive.

here is a link to repair info for your truck, including expansion valve installation
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check you can see refrigerant in the sight glass on the reciaver drier when the system is on . sometimes under load and low rpm the a/c system will shut off to prevent the engine stalling . check if it works around town then on over a constant distance