Constant movement of the converter clutch regulator valve wears the Ford E4OD, 4R100 pump body bore. A worn bore causes high or low converter apply pressures depending on area and extent of wear. The most common is wear at the balance end, causing high converter pressure and internal converter damage. Severe wear in other areas of the bore allows large amount of converter oil to leak to exhaust, lowering converter and converter clutch apply pressure and cooler/lube flow. Use of the Sonnax oversized converter clutch regulator kit 36424-11K corrects these problems by resizing the pump body bore and restoring circuit integrity.
A vacuum test at the port indicated fails to hold at least 18 in-Hg.