Transmission Thermal Bypass Valve - Ford Truck Enthusiasts Forums

Go Back   Ford Truck Enthusiasts Forums > Newer Light Duty Trucks > 2004 - 2008 F150
Log In 

2004 - 2008 F150 2004, 2005, 2006, 2007 and 2008 Ford F150's with 5.4 V8, 4.6 V8 or 4.2 V6 engine

Transmission Thermal Bypass Valve

LinkBack Thread Tools Search this Thread
Old 03-04-2009, 06:52 AM
Jim Allen's Avatar
Jim Allen Jim Allen is offline
Elder User
Join Date: Dec 2006
Location: On a farm.
Posts: 559
Jim Allen is starting off with a positive reputation.
Transmission Thermal Bypass Valve

As many of you know, most of our '04-08 F-150s have a temperature controlled bypass valve for the transmission that bypasses the coolers until the trans oil temp reaches about 185 degrees (this is according to some Ford documentation I just received). The unit looks like a square block and is in the cooler lines near where the engine meets the bellhousing. The idea behind it is to keep the trans from overcooling. Also, the torque converter does not lock up until trans oil temp reaches about 85 degrees, and Ford wants to hasten than point.

I can think of reasons to like this device and I can think of reasons not to. A tranny rebuilder on another FTE board claims this unit is notoriously unreliable and when it fails, it more or less permanently bypasses the coolers and leaves the trans vulnerable to overheating. I can see how that could happen.

Thing is, thus far, I'm not hearing much from other sources to back up his statements. Not calling him a "laar" because his particular experience could lead him to that conclusion. I'm looking for broader evidence, so if anyone out there has a story on this device to relate, or knows someone who does, would love to hear. In the meantime, I am contacting other sources to work up my data.
1986 F-250HD XL 4x4 6.9L, Banks Turbo, C6, 4.10:1 Truetrac, 285/75R-16
2005 F-150 XL 4x4 5.4L, 8200 GVW, 4.10:1, Rancho Quik Lift, Gryphon Prog, Dynomax exhaust, AEM Brute Force, 285/70R-17D Cepek FC-II, TrailReady bumper, MileMarker V10 winch, Painless 200A alt.., Auburn rear LSD
Reply With Quote
Old 03-04-2009, 07:34 AM
DarrinBC's Avatar
DarrinBC DarrinBC is offline
Senior User
Join Date: Jul 2008
Posts: 167
DarrinBC is starting off with a positive reputation.
BC Automotive
This 'tranny rebuilder' wouldn't happen to be dirtydog would it?

For the record, I haven't seen problems with the thermal bypasses.

Any chance you can pm or email me a link? I want to read this one myself.

Reply With Quote

Similar Threads
Thread Thread Starter Forum Replies Last Post
Use the trans cooler in radiator or not? mototrig 1999 - 2003 7.3L Power Stroke Diesel 15 01-17-2014 06:20 PM
Anybody ever bypass the coolant valve on the intake? wastingas Expedition & Navigator 0 08-23-2013 01:44 AM
Write Up: Bullet-Proofing the 6.0L PSD. colo_dually 6.0L Power Stroke Diesel 22 06-18-2011 10:10 PM
Transmission Cooler Bypass E4OD linckeil 1987 - 1996 F150 & Larger F-Series Trucks 2 09-12-2009 11:02 PM
98 trans. cooler bypass valve is singing on E40D rangedog Expedition & Navigator 2 03-25-2004 09:58 PM

Go Back   Ford Truck Enthusiasts Forums > Newer Light Duty Trucks > 2004 - 2008 F150

bypass, f150, ford, location, thermal, transmission, valve

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Forum Jump

All times are GMT -5. The time now is 07:30 AM.


Advertising - Terms of Use - Privacy Statement - Terms of Service - Jobs
This forum is owned and operated by Internet Brands, Inc., a Delaware corporation. It is not authorized or endorsed by the Ford Motor Company and is not affiliated with the Ford Motor Company or its related companies in any way. FordŽ is a registered trademark of the Ford Motor Company.

vbulletin Admin Backup