5R55E Pressure Tests | Ford Explorer Forums - Serious Explorations

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5R55E Pressure Tests

Paul Fithian

Elite Explorer
October 12, 2016
Reaction score
City, State
Long Beach, IN
Year, Model & Trim Level
2007 Job 1 RWD V8 Limited
In another thread (http://www.explorerforum.com/forums...55e-valve-body-sonnax-zip-kit-install.460623/) I described installation of a Sonnax Zip Kit as well as weak reverse afterward. I had also adjusted the new Bosch EPC solenoid to smooth out the downshifts..

I was able to put a pressure test gauge on the transmission Line port and record pressures, along with the ATG Line Pressure Specifications No. 401 for a Ranger:

Both reverse pressures are below spec, and D WOT is below spec.

I was not able to put the gauge on the EPC port, as the cat converter blocks access to it.

How do I fix this?

Here are the pressure readings

Pressure Readings 7-14-2017.jpg

Perhaps a refurbished valve body would fix this reverse low pressure issue? The transmission works perfectly in all gears except for reverse, it slips when backing up a hill or with a trailer.

I can report that a replacement valve body from Shift Rite with an installed TransGo shift kit completely solved the weak reverse issue I was having with this transmission.

I have not done a pressure test, but reverse is strong under load, no slipping at all.

Shifts quickly and smoothly now in all gears, just like new.

Here's the valve body I installed: https://www.amazon.com/Shift-Rite-T..._rd_t=40701&psc=1&refRID=9FR0QBWKGVV8EM96ZDMQ