[Rockyaa]

Smokey, I've just changed fluid in my 01 F350.
I had some flow through the bypass valve which I caught in a second bucket.
I know my cooler is clean, so I don't think a clogged cooler is the problem.
Air temp this morn was 95 deg, so cold is not a problem...(I live in Waco, TX)
I just returned from a lengthy trip through Wyoming and Colorado.
I had considerable trans heat problems...it would get around 195 to 200. I pulled over, let it cool several times.
I've never had an overheat problem before while pulling my 5th wheel camper, in the same areas.
Could it be that the bypass is weak letting the fluid bypass the cooler?
It's a BTS tranny.

 

[fulltimer50]

Best thing to do is to give Brian at BTS a call. He will know whats wrong.

 

[Mark Kovalsky]

I had considerable trans heat problems...it would get around 195 to 200.

That's not hot, that's normal temperatures. You're wasting your time if you're cooling the trans when it's that cool.

If the bypass is leaking, and yours appears to be, either there is a restriction somewhere in the cooler circuit or the bypass spring is weak and letting the bypass open when it shouldn't.

 

[OBXNC]

I guess I'm stupid but what by-pass valve are you talking about? I've flushed mine four times and only disconnected the return line for the flush procedure.

 

[Rockyaa]

OK, thanks Mark.
I'll check the bypass, probably just replace it. I know the cooler is not clogged.
I blew it out...it's clean. My thinking was that if fluid is bypassing the cooler, even partially, that would account for higher temps than I've had in the past. At 200 deg, it begins to blow fluid out of the vent when I'm climbing some of the Colorado passes.
Your fluid change procedure worked fine...but it some fluid came through the bypass. I understand others have had that problem when pumping out the old fluid.

 

[Mark Kovalsky]

If you have fluid coming out of the vent at 200°F the transmission is overfilled. That will also cause the temperatures to rise.

 

[RT]

I guess I'm stupid but what by-pass valve are you talking about? I've flushed mine four times and only disconnected the return line for the flush procedure.

If you climb under your truck on the passenger side, you'll notice the front and rear transmission lines are connected with banjo fittings with a line going between them. In the middle is a spring loaded valve that permits fluid flow should the coolers plug. If the spring gets weak, the valve can stick open short circuiting the coolers causing an overheat issue.