Trans Cooler Bypass Valve Help

[Oddball]

I read somewhere a while back that to check to see if the bypass is working correctly you just dissconnect the hot (supply side) of the lines where they enter into the cooler. Then you run the truck for a few seconds to make sure that fluid is flowing thru the hot supply line and that no fluid flows backwards from the return (cooled fluid side).

So today, I drove the truck around until the trans warmed up to about 150 degrees. I tried this test and I had major flow from both sides. If I understand this correctly I need to replace my Cooler Bypass Valve. Can someone please tell me if I am doing this correct?

If I do need to replace it, do I have to drain all the fluid first?

[sikktruk01]

[Log Dog]

Bump!!

Isn't there a way to eliminate the bypass valve all together?

[Log Dog]

Anybody???

[chappy]

yes there is.you just take the bypass valves off and braze the 4 holes shut and put it back on.You just have to make sure you don't block the inside of the bolt passage any.Johnwoods also sells the brass bushings to cover the holes up also.I have heard mixed reviews on this.I know John woods don't like it and always does this mod but others have suggested that with this mod,if the tranny cooler or lines got plugged,then they wouldn't flow and it would burn up the trans but with the bypass,then it would still bypass and flow .
I figure they have never really had problems in the past before the bypass valve was intruduced that I know of, so why not do it.Only problem on mine is,its an early 99 and I don't have the radiator lines on mine to help with initial warm up so,without the valve in winter,it would take a little longer to warm up,but not sure how long.

[Log Dog]

thanks!!

[BruceM]

Any reason one wouldn't want to say go 50% on that brazing up of the holes on the bolt? I know thre are 4 holes in the bolt, one could braze 2 shut and leave 2 open, thereby at least providing some flow in the event of a cooler plugging type of situation.

I flushed my transmission out and it was fairly cool when I did it, and I had good flow out of my disconnected cooler line when I did it. Only had flow out of the line that was heading back to the tranny from the cooler. My trans ran pretty warm till I got a Tru-Cool on there, now I am only 50-60F above ambient and at idle it starts dropping even at stoplights. I have to pull my tranny soon to fix a pump seal leak and I was thinking of brazing 2 of the 4 holes shut to get a little extra flow to the coolers. cheaper than replacing the bypass completely.

Before the additional cooler I would see temps climb up to about 180 while driving along on the highway, and in stop/go it would peak about 200F. Which significantly sped the exit of tranny fluid from my leaking pump seal.

[cchase]

I wouldnt bypass the bypass, just replace it. when its warmed up, just grab the line and if its hot it isnt working.