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1949 Ford Coupe RESURRECTION
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Discussion Starter · #1 ·
I'll keep this short. At what point in the oil flow system of a 700R4 is the pressure port? Is it directly off the pump? Or does the oil goes through the cooler lines first. Sorry I've googled my butt off and have not found out the answer.

I have good pressures when cold, but after warm up, all are way down. I'm a little suspicious of my looong SS braided cooler lines is the reason for the question, but any ideas would be greatly appreciated.

TV cable is ok... works great when cold... other issues may be asked on another thread later on.....

Thanks in advance..
 

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I'll keep this short. At what point in the oil flow system of a 700R4 is the pressure port? Is it directly off the pump? Or does the oil goes through the cooler lines first. Sorry I've googled my butt off and have not found out the answer.

I have good pressures when cold, but after warm up, all are way down. I'm a little suspicious of my looong SS braided cooler lines is the reason for the question, but any ideas would be greatly appreciated.

TV cable is ok... works great when cold... other issues may be asked on another thread later on.....

Thanks in advance..

Pressure tap in on the drivers side it is for reading regulated pressure. The TV cable and the pressures it sets are a pretty wide range depending upon model of the 700R4. You need to get some guides on setting these things up. Much data is on line, just GOOGLE for it.
Example:
https://www.google.com/imgres?imgur...hUKEwiXu6SR1tnTAhVQ0mMKHbQxCzIQ9QEIMzAA#spf=1



Pressures:


Bowtie Overdrives - Pressure Gauge Installation Instructions


TV adjustment
Art Carr's 700r4 tv cable adjustment guide from CPTtransmission.com



Bogie
 

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1949 Ford Coupe RESURRECTION
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822 Posts
Discussion Starter · #3 ·
Thanks, but you didn't answer my question... TV/pressures/etc. are all fine. please read my post again... thanks anyway
 

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Thanks, but you didn't answer my question... TV/pressures/etc. are all fine. please read my post again... thanks anyway

Cooler line pressure is much lower than pump or control pressure it ranges from 20 to maybe 80 PSI depending upon gear and TCC application.


I'm not aware of any external tap that shows unregulated pump pressure.


I'd recommend you monitor trans oil temp this has a big influence on pressure when it gets hot and thins.


Bogie
 

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1949 Ford Coupe RESURRECTION
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822 Posts
Discussion Starter · #5 ·
Thanks Bogies.. so is that to say that the pump discharge shoots fluids to the valve body/etc. and there is a branch maybe pressure controlled that branches off to the cooler lines ? The thing is that it seems rather weird that it works perfectly (sorta) when cold, then goes to hell after maybe 15 minutes...
 

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Thanks Bogies.. so is that to say that the pump discharge shoots fluids to the valve body/etc. and there is a branch maybe pressure controlled that branches off to the cooler lines ? The thing is that it seems rather weird that it works perfectly (sorta) when cold, then goes to hell after maybe 15 minutes...

Are you taking pressures at the upper port on the drivers side and if you are what are they doing. That port is the control pressure which varies by gear selection and RPM. Pressures are different by model of the transmission. Certainly you need to see where these pressures are going after this warms up, but 15 minutes is a lot faster than I'd expect the trans to get hot in that short time. Ideal temp is 150-180F. Stalled in traffic might see 220-240 which will thin the oil and drop pressures.


Here's some links that may help:


ID the model of 700R4


https://www.google.com/imgres?imgurl=http://hotrodders.com/forums/images/bulk/TH700-R4_1.jpg&imgrefurl=http://www.chevelles.com/forums/152-2009/281882-help-me-identify-700r4-l460-l460e-see-pictures.html&h=322&w=376&tbnid=p7xrYDoFsURGnM:&tbnh=160&tbnw=186&usg=__Njq0XtFxLUQ_n4Z3lum6oNvtT7A=&vet=10ahUKEwiXu6SR1tnTAhVQ0mMKHbQxCzIQ9QEIMzAA..i&docid=md-kpw-ilmelvM&sa=X&sqi=2&ved=0ahUKEwiXu6SR1tnTAhVQ0mMKHbQxCzIQ9QEIMzAA#spf=1


Pressures; these will be different if the trans has been modified but they are a starting place:


http://www.tvmadeez.com/press_gauge/pressgauge.html


TV Adjustment just incase:


http://www.tvmadeez.com/press_gauge/pressgauge.html






Bogie
 

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The main line pressure port on the trans case Driver's side. It is a direct feed from the pump port that feeds the transmission. The pressure seen there is altered by gear selection , TV setting & other mods made to the trans via boost valve size, PR spring strength

The pump also feeds the oil to the torque converter to fill the converter. This is a separate regulated oil feed into the torque converter from the pump. This oil flows through the pump section , input shaft, converter hub etc

The "out" cooler line fitting on the passenger side of the case is directly from the converter. This converter oil flows through the pump stator support tube area, around the input shaft, through holes in these parts. Oil flows in to & out of the converter constantly if the engine is running & transmission pump is turning.

The return oil from the cooler system enters the lubrication system of the transmission to remove heat and lubricate the moving parts
 

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1949 Ford Coupe RESURRECTION
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822 Posts
Discussion Starter · #9 ·
Since you seem to know a lot about the subject, would you have a theory as to why my pressures go to hell once it heats up?
 

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Since you seem to know a lot about the subject, would you have a theory as to why my pressures go to hell once it heats up?
If the main line pressure is dropping as the trans heats up. The clearances inside the pump are loose. That is the usual cause, if the remainder of the trans is in good condition.

This can be from wear, incorrect setup , surface of the pump cover not flat, surface of the area the rotor & slide ride on in the pump body are not flat. Wear on the vanes & surface area of the rotor will affect pressure too

Side clearance on the rotor needs to be setup at .0015 to .002 , this is where I set them up at. Everything needs to be flat sanded , so they are flat & smooth as possible. I usually finish with a 400 or 500 grit paper on a known flat surface like a machinist marble table or similar
 
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