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Just need some clarification about marking of the pressure taps on the 4r70w. Well some I can figure out for my self but a complete list would be great so any doubts can be eliminated. Some one can certainly help me out as I’m a novice in 4r70w troubleshooting.

Drivers side: Line = Line Pressure?
Passengers side: Direct = ?, FWD = Forward Clutch?, TV = Throttle…?(EPC pressure??), INTER = ?

I’ve searched this forum and on the web but I can’t find any complete explanation of the abbreviations. In the “4R70W Rebuild Checklist” (http://www.mn12performance.com/mn12-techinfo/trans-tech/4r70w_rebuild.html) it´s stated that the pressure taps are “clearly MARKED right on the case on AODE's & 4R70W's” and how to measure between taps to check for leakages in the trans. This is what I’m about to do in my slippery trans. now equipped with a J-mod -99 valve body. Before I had a neck-breaking transgo kit witch worked well except for the very, very firm shifts. And yes I didn’t change the epc-solenoid so now I’m trying to troubleshoot it with gauges in the tranny to see if it’s fully operational. Have also logged the tranny with my XC2 but I don’t really know what to look for so some help in that subject is also welcome!
 

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Discussion Starter #2
Tank’s for all support and answers I’ve gained in this thread! Well I’ve now cleared this one my self, I think?

Drivers side: LINE = Line Pressure
Passengers side: Direct = Direct Clutch, FWD = Forward Clutch, TV = EPC solenoid pressure (Electronic Pressure Control), INTER = Intermediate Clutch

What TV stands for I haven’t figured out jet but the Ford Original Line Pressure Test procedure for 1994 Thunderbird states that EPC tap is the one in the “middle” with a clarifying picture of the location.

Any tip of how to get more response for a newbie would be of great interests!
 

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dirtydOg and Darrin seem to be the experts on these transmissions. I'd try PMing them. There are a few others, but their names don't come to mind.

That's the best I can do as your questions are way above my knowledge base.
Rob
 

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The problem is trying to identify the taps. The driver side is line pressure the ones on the passenger side I believe are reverse forward and direct. I really suggest an atsg manual to identify them that will also tell you what pressures should be.
Alan
 

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Well TV is Throttle Valve, but the 4R70W doesn't have a throttle valve, which is the valve that is connected to the throttle lever via the kickdown cable. It is electronically controlled, so the computer uses the TPS to sense throttle position instead. The AOD does use a TV cable, and is related to the 4R70W so it may just be part of the old casting they are using for the newer trans?? EDIT: Alan is right, there's got to be one for the reverse circuit...and I don't recall seeing a port labeled TV on any 4R's. Are you sure you read it right? If so then it probably just reads EPC pressure like you said, given the lack of a TV system on our cars/trannies.
 

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Discussion Starter #7
So this TV port is the EPC pressure? The EPC pressure that you should be able to check according to Ford's original T-bird manual? The manual states five pressures that you should be able to check on the trans. Line, Direct clutch, Forward clutch, Intermediate clutch and the EPC pressure. The markings is logical to them all except for the TV marking. But in the other hand the epc solenoid in these modern trans has replaced the old Line pressure adjusting devices like kick down cable and vacuum devices...
Well if some one has the experience of how a failed EPC solenoid 4r70w tranny is behaving when you check the pressure taps, please cheer it with us...
My tranny has, as it seems, a constant low line pressure. It don't rises when I stall it. It constantly low about 45psi. And that is according to ford's spec. ok when idling, but it should rise when a gear is engaged and tacking of. Well mine don't. On the other pressure taps the line pressure seems to be when its supposed to but the TV tap (EPC pressure?) is always zero, no matter what! That's why I´m now is about to replace the EPC solenoid to see if a new one makes any difference. As I understands it they always have a high failure rate and when rebuilding you always replaces them. I'll let you know how my troubleshooting is proceeding......
 
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