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Trans cooler lines which is which

38K views 44 replies 21 participants last post by  Jon 
#1 ·
Is there a general rule which trans cooler line on the radiator is the forward and the reverse one? I have a 1980 Monte and need to know to hook in the additional cooler in the right place.

Regards
Martin
 
#27 ·
I would disagree. The engine is running cooler because the tranny cooler was blocking air flow to the rad. Now the tranny cooler is picking up heat from the rad causing the tranny to run hotter. Even though the engine is running 5 degrees cooler. The tranny cooler is now picking up 180 degree cooling air from the rad. It was getting 70 degree ambient cooling air from in front of the rad.
 
#28 · (Edited)
"H" - Fitting

I'm also an Alberta resident, and I am back working at a Ford dealership again.

When I worked for Ford in the mid-80's I recall that they were concerned with fluid viscosity in cold climates. Apparently very thick fluid was causing starvation / cavitation (?) precipitating in transmission failures.

Thier "fix" was to install an "H" fitting in the cooler lines fairly close to the transmission. If the fluid was too thick, it would take the path of least resistance (thru the middle of the "H") and bypass the cooler altogether.

As the fluid warmed to operating temperature (at both ends) it would thin out and flow straight thru the "H" ... again taking the path of least resitance. The theory makes sense to me and I applaud them for coming up with something simple and effective.

I'd have to check the part number when I get back to work, but I think the ford basic# is 7G118. (E3TZ-7G118-A?)

On second thought ... that basic# is likely 7H322
 
#29 · (Edited)
66GMC said:
As the fluid warmed to operating temperature (at both ends) it would thin out and flow straight thru the "H" ... again taking the path of least resitance.
I'm certainly no engineer but:
Seems to me that, after up to operating temp the the path of least resistance may still be across the H, regardless of two 90 degree turns, since the fluid foward of that point that is returning from the cooler is just that; 'cooler', therefore a thicker viscosity. That would mean the thinner fluid leaving the tranny would create a condition of a greater percentage of the hot fluid bieng returned back to the tranny {uncooled}. Also there is the factor of a much less distance accross the H and not needing to overcome resistance created via pumping through the flews of the cooler.
I could see it being a good idea if there was a manual thermal check valve in the cross feed line that was normally open per colder temp.
I don't foresee needing to make a modification like that here in Mississippi, but I can see where it would be an excellent system to help prevent thick fluid cavitation problems up there where you guys see some really cold temps.
If you can, when you check on that #7H322, see if you can find a schematic to look at to make sure they did not install a check valve in the cross-feed line.
Thanks for some valuable info 66GMC. ;)

EDIT:
BTW; I see YOUR PASSENGER listens well, "Get in, sit down, hang on". LOL :D
 
#30 ·
Well, I've done a little more research from home on this.

http://www.fahringer.net/x/4r100disasm.htm
Have a look at item #122.

It appears that the technology may have changed SLIGHTLY on this, but I'm fairly convinced that 7H322 is the right "basic" number...

Ford now calls this a "CBV" (Ford has acronyms for everything :D )
CBV = Coolant Bypass "Valve" ... which implies what you are thinking about.
It appears to be a tube attached directly to the transmission case, and mounted using banjo fittings.

The old "H" fitting that I mentioned previously sure didn't look like it had any type of check-valve or restrictor at all, but I may be wrong in assuming that.

I couldn't find anything on my Ford (Dealer Only) website, but this TSB may be relevant and contain the part number if you can dig it up somewhere.

From: http://lsc.netherealm.net/1984.html

Service Bulletin Number: 83-18-9
Bulletin Sequence Number: 023
Date of Bulletin: 8309
NHTSA Item Number: 70923
Make: LINCOLN
Model: MARK VII
Year: 1984
Component: POWER TRAIN:TRANSMISSION:AUTOMATIC:COOLING UNIT AND LINES
Summary: TRANSMISSION-AUTOMATIC-ALL-AUXILIARY COOLER BYPASS FITTING ("H" FITTING)-(C- 3, C-5, OR AOD MODEL TRANSMISSION)-PROCEDURES FOR CHECKING/CLEANING COOLER LINE AND COOLER IN 1984 MODEL LINCOLN, MARK VII AND CONTINENTAL
Perhaps Fitzwell or XNTRIK or Max Keith... anyone with a lot of Ford knowledge will jump in on this thread and confirm or deny the PN and how it works.

And yeah ... the "Hang On" picture in my Avatar is priceless. :D
A friend had sent me an e-mail entitled "You know you're driving too fast when..." followed by the pic. I sent a request to Jon to use it as my Avatar.
Don
 
#31 ·
66GMC said:
Well, I've done a little more research from home on this.

http://www.fahringer.net/x/4r100disasm.htm
Have a look at item #122.
{122 7H322 Valve assembly — transmission cooler bypass (model dependent) } decribes a 'valve' and it looks like maybe right next to that rear banjo fitting.

I couldn't find anything on my Ford (Dealer Only) website, but this TSB may be relevant and contain the part number if you can dig it up somewhere
I can't find anything for Ford but I just remembered I dug up some TSB's on a 94 Dodge van that I rebuilt the tranny in a few months ago and a TSB was listed for:
-----------------
A/T - Cooler Bypass Kit/Restricted Fluid Flow
NO: 21-03-95 Rev. A
GROUP: Transmission
DATE: Jun. 16, 1995
SUBJECT:
RWD Automatic Transmission Cold Temperature Cooler Bypass Kit
THIS BULLETIN SUPERSEDES TECHNICAL SERVICE BULLETIN 21-03-95 DATED APR. 14, 1995 WHICH SHOULD BE REMOVED FROM YOUR FILES. 1993 MODEL YEARS HAVE BEEN DROPPED. ALL REVISIONS ARE MARKED WITH AN **ASTERISKS**.
MODELS:
**1994-1995** (AB) Ram Van/Wagon
**1994-1995** (AN) Dakota
**1994-1995** (ZJ) Grand Cherokee
1994-1995 (BR) Ram Truck
SYMPTOM/CONDITION:
At ambient temperatures of -15 degrees F or below, vehicles equipped with auxiliary transmission coolers may experience a lack of transmission fluid flow to the transmission. At these low temperatures, the automatic transmission fluid might freeze in the transmission cooler lines restricting fluid flow. This can cause damage to the transmission, and in periods of extended driving, transmission failure may result.
DIAGNOSIS:
The cold weather by-pass kit should be installed if any of the following conditions are met:
1. If the vehicle is used in areas of extended cold ambient temperatures (below -15 degrees F).
2. If the transmission has failed in cold ambient temperatures, install the bypass kit when repairing or replacing the transmission. Follow proper cooler flushing and transmission replacement procedures found in the Dodge Ram Service Manual.
Note IN HOT AMBIENT TEMPERATURES, THIS KIT WILL DECREASE THE COOLING CAPACITY OF THE TRANSMISSION COOLING SYSTEM. AS A RESULT, UNLESS THE ABOVE STATED CONDITIONS EXIST IT IS NOT RECOMMENDED THAT THIS KIT BE INSTALLED.**
POLICY: Reimbursable within the provisions of the warranty.
TIME ALLOWANCE:Kit, Transmission Cooler Bypass 1994-1995 (BR)
Install 1994-1995 (ZJ)
1994-1995 (AN)
1994-1995 (AB)
FAILURE CODE: P8 - New Part
------------
I haven't been able to find a diagram for the valve but I have the part# 04798633 and adaptor p/n 04798634.
I don't know why "Note IN HOT AMBIENT TEMPERATURES, THIS KIT WILL DECREASE THE COOLING CAPACITY OF THE TRANSMISSION COOLING SYSTEM." But that has my curiosity.
 
#32 ·
mike 96 ws6 said:
{122 7H322 Valve assembly — transmission cooler bypass (model dependent) } decribes a 'valve' and it looks like maybe right next to that rear banjo fitting.
Yeah, that 7H322 is the bypass tube ... and it uses the same Ford 'basic' part number as what the older "H" fitting I've been talking about.

You see, ford 'basic' numbers remain the same across all applications ... (Pinto to Heavy Truck) ... only the Prefix/Suffix changes. For example, the 'basic' number for a fuel tank is 9002 . The complete part nunbers might be something like D1FZ-9002-A for the Pinto, and D0HZ-9002-C for the heavy truck.

Basic numbers become like a second language to a Ford Partsmen.

I haven't been able to find a diagram for the valve but I have the part# 04798633 and adaptor p/n 04798634.
I don't know why "Note IN HOT AMBIENT TEMPERATURES, THIS KIT WILL DECREASE THE COOLING CAPACITY OF THE TRANSMISSION COOLING SYSTEM." But that has my curiosity.
I found a little more info on the Dodge one for you ... but still no picture.
http://home.sc.rr.com/janet/TSB/21-07-97.htm

This one DOES sound like it has both an orifice and a check valve, implying that a certain amount of fluid is being FORCED to bypass, rather than allowing fluid dynamics to control the flow ... as I imagine the low-tech "H" fitting to be?

Either way ... I suppose that just about ANY cooler by-pass system would DECREASE the efficiency unless it was, as you say, thermostatically controlled in some way.

I'm going to bookmark the NHTSA website ... even though the interface sucks a little, and they only seem to have 2002+ info
 
#33 ·
Duce is correct with his graphic, however the pluming that I have serves the purpose that I run very well. I mention that I am running a converter with 3400 of stall, keeping this in mind and realizing that most of the time when driving in traffic the RPM of a motor is mostly 1200 - 1800 , so that means I have some amount of stall until my motor reaches the drive parameter 3400. It seems to me that a need for the tranny fluid to be warmed through the radiator water becomes a mute point is the configuration ...... for the stocker types Duce's digram applies and Hayden is a great source of information and product. Just not the finial word or set up.
 
#34 ·
OK, here's the latest on that "H" fitting...

My first thought was what I now believe to be correct... :rolleyes:
I was real CLOSE on the part number as well...
I originally thought it was E3TZ-7G118-A,
but it turns out to be E3SZ-7G118-A... which is now obsolete anyway :(

There is only one available at ONE Canadian Ford dealership (Metro in a suburb of Vancouver, British Columbia.)

The original TSB was number 82-22 released in late 1982.
I was not able to find the actual bulletin to get the actual text or any diagrams, etc... all that I can find in the Microcat catalog is a reference to that TSB.

Sorry for the "wild goose chase" ;)
 
#35 ·
pepi said:
Deuce is correct with his graphic, for the stocker types Deuce's digram applies and Hayden is a great source of information and product. Just not the finial word or set up.

I have a switch pitch 400 Turbo in my 32 Roadster with a 800/2800 stall converter.......and that's the way I have mine run. :D except the cooler is NOT in front of my radiator.

I believe that the cooler before the radiator is the BEST way...at least for my car.. :) the extra cooler cools the fluid BEFORE it goes to the radiator....and helps the radiator cool even better......because the radiator then dissipates heat to the transmission fluid.....getting it back up to the recommended operating temperature recommended by MOST transmission people. The fluid needs to be warm to work the best...just not real hot.

:thumbup:


This is another question that has MANY opinions and most will not be changed..... :smash: NO MATTER what is posted....
Like the eternal
1) 8 inch Ford is strong enough for a 350 HP engine
2) Model A frames are OK...boxed with no crossmembers
3) Mustang II suspensions are great for everything ( even 5500 lb. cars )
4) Aluminum VS brass radiators cooling effectiveness
5) Rubber lines VS hard lines for fuel and such ( transmissions too )
6) Holley VS Edelbrock.......carbs
7) exhaust manifolds VS headers....
8) stainless lines (37 degrees VS double flare )
9) Frame swaps are easy to do....and are possible for every car :nono:
10) Homemade wiring kits VS EZ wire VS Painles VS RonFrancis VS...... :confused:

I could go on and on.....and I know you guys could add a bunch also but it's late.....I am going to BED...

.
 
#36 ·
tranmission cooler

For what it is worth I have had tired the cooler in front, then back of the radiator with a elect. fan on my 36 Chevy coupe with a 350/700r4 and I didn't see where it made a difference as to the heat built up. I ran it this was for over 12 years. Now I have the cooler mid way back under the car. Still no problems. I think as long a you have air flowing across the cooler you would be ok. Dan
 
#37 ·
chiss said:
I took one ( trans cooler) off a Crown Vic police car in the junk yard a few weeks ago, It was on the return line, It being a police car and as hard as they are driven, I would guess thats the best place for them.


That sounds sort of risky getting a tranny cooler from the salvage yard (there less than $20.00 new), how do you know the tranny in that vehicle didn't take a crap and that's why it's there in the junk yard. Then you put that cooler on your vehicle and run all the metal filings through your tranny :nono: NO!!.... NOT GOOD!!..... BAD BOY!! :nono: (LOL). In reference to the direction of fluid flow through the cooler , why does it make any difference what direction the fluid flows anyway, all the coolers are is just a twisty hollow tube, nothing different than a tranny line to or from the radiator :confused: Supposing you hook the lines one way or the other on the cooler, what difference does it make. It will still flow right. The only difference I see is that with the lines hooked one way, the fluid would travel through the cooler first, then rad. With the lines the other way it would flow through the rad. first, then cooler. BUT......depending on where you PUT the cooler, in front of,,, or behind the radiator(which is anyones discretion), it could heat OR cool first or last before returning to the tranny. Am I wrong on this?
 
#38 ·
junk yard coolers

Man, Don't use a junk yard cooler, For a few bucks more get a new one! Otherwise you may end up doing the cooler job twice. Also if you are going to put it on the radiator be real careful you don't punch a hole in the core. And it can happen as I did it once. Good luck on your project. Dan
 
#39 ·
STATUTORY GRAPE said:
That sounds sort of risky getting a tranny cooler from the salvage yard (there less than $20.00 new), how do you know the tranny in that vehicle didn't take a crap and that's why it's there in the junk yard. Then you put that cooler on your vehicle and run all the metal filings through your tranny :nono: NO!!.... NOT GOOD!!..... BAD BOY!! :nono: (LOL).
Provided the cooler is not damaged, the lines that twist back and forth are smooth on the inside and should not trap any metal from a previous install that some solvent and some compressed air will not clean out. One of my auxillary coolers was previously an oil cooler on a 96 Chevy 3500 HD Diesel truck. That Deisel motor took a bad crap in the bottom end, but the oil cooler cleaned out easily with a can of brake parts cleaner and some compressed air.
it could heat OR cool first or last before returning to the tranny
That's the whole point discussed throughout this thread. If the ambient air temp is say 0 degrees, this can cause the fluid returning to the tranny to be TOO cool for proper lubrication and operation of the transmission.

I run 2 external coolers and also the cooler housed within the factory radiator. I previousl had the fluid lines connected so that the fluid went through the radiator first, then through the externals.
After reading this thread a few weeks ago, I switched the direction so the fluid goes through the radiator last.

Before:
I had an issue with the 2-3 shift feeling like the pressure plates are bouncing off of the friction disc at the first cold shift, and also like the 2-4 band is still being engaged momentarily by that apply circuit for a split second after the 2-3 shift. This issue has been mainly during the first minutes of 'cold-start-up' operation all summer, but now with cold weather, it is prolonged and even to the point of doing it continually in extremely cold conditions.

After the cooling fluid flow direction change:
It still does the same thing when cold, but the problem clears up quickly as the operating temperature rises and after the engine coolant is up to temp, it shifts fine, even when it's very cold outside.

This 2-3 shift problem is a result of extensive internal modifications to the tranny aimed at very quick and hard shifts {for the drag strip}, which the 4l60e is just not very fond of. Those modifications serve there purpose very well although this little 2-3 shift thing turned out to be a by-product. But it is very noticable, and gave me an excellent oportunity for an indication of the differences produced by the temperature of the fluid being returned to the tranny.

Wow. I learn a lot around here. :)
 
#40 ·
The point of a trans cooler is not to cool the fluid as much as you can. The point of a trans cooler is to keep the fluid from overheating/boiling. Trans-fluid should be 160-190 degrees, 175ish being just right. Keeping transmission fluid continually cold can cause severe transmission damage. The trans lines should be routed from the trans, to the cooler, to the rad, and back to the trans. The radiator will either cool or warm the ATF to operating temperature. This is why every manufacturer routes ATF through the coolant, to bring and keep the ATF to correct operating temp. If the point was just to cool the ATF, then we would have a thermostat in the trans lines. ie the point of coolant is to cool the engine, not warm it up, so we have a thermostat. (simplistically)
 
#41 ·
arch said:
The point of a trans cooler is not to cool the fluid as much as you can. The point of a trans cooler is to keep the fluid from overheating/boiling. Trans-fluid should be 160-190 degrees, 175ish being just right. Keeping transmission fluid continually cold can cause severe transmission damage. The trans lines should be routed from the trans, to the cooler, to the rad, and back to the trans. The radiator will either cool or warm the ATF to operating temperature. This is why every manufacturer routes ATF through the coolant, to bring and keep the ATF to correct operating temp. If the point was just to cool the ATF, then we would have a thermostat in the trans lines. ie the point of coolant is to cool the engine, not warm it up, so we have a thermostat. (simplistically)

Some manufacturer's must be different, I just hooked one up yesterday on a '95 Jeep and the instructions said to go from trans, to rad, to cooler, then back to trans. It said hooking this way "provides maximum cooling by returning coolest fluid directly to transmission".
 
#42 ·
STATUTORY GRAPE said:
Some manufacturer's must be different, I just hooked one up yesterday on a '95 Jeep and the instructions said to go from trans, to rad, to cooler, then back to trans. It said hooking this way "provides maximum cooling by returning coolest fluid directly to transmission".
That is correct, "maximum cooling by returning coolest fluid directly to transmission" but in some circumstances this is not desired, especially if you operate your vehicle in northern Canada in the winter months at very cold temps. Your user information says you are in Wisconsin. I live in Mississippi and I'm sure it gets much colder there than it does here. If I can notice a difference in my shift problem that I posted about, with temps getting pretty cold for here, then I would think the advantage of the tranny fluid flow being routed opposite of that manufacturers directions would be a very good suggestion for me to consider for a vehicle operated in Wisconsin. I'm sure the fluid manufacturers also have some guidelines concerning use of their product at sub-freezing temperatures, although maximum cooling would likely not be included for suggested proceedures in those conditions.

arch said:
If the point was just to cool the ATF, then we would have a thermostat in the trans lines. ie the point of coolant is to cool the engine, not warm it up, so we have a thermostat.
I agree with your post and I realize this is being a little picky, but the thermostat in the engine coolant circuit is designed to do just that, warm the coolant to a temperature that is desired for proper operation. Without the thermostat, the coolant can stay at a temperature below what is desired, especially with a low ambient air temp as is discussed already throughout this thread, although concerning the transmission fluid instead of engine coolant {and you will take notice of this on a cold day when your heater is blowing cold air}.
Also, the idea of a thermostat in the transmission fluid cooling circuit is not a bad one, although there would need to be a bypass circuit routed with the thermostat in, to an extent, that flow path in order to open it when needed. But there is no need for this since the engine coolant thermostat can accomplish the same task, free of any other system needing to be involved, and at a temperature that is acceptable for this BUT the factor of cold fluid pump cavitation and lack of lubrication at low temperature would be better addressed by a bypass with short fluid travel distance because of the difficulty of pumping that cold fluid through extended line distance, just as Ford utilized, which was pointed out in previous post by Don, {66GMC}.
And arch, as I said, "don't mean to be picky", but the internet is dead tonight and I just felt like typing alot. But I do try to help when I can ;)
 
#43 ·
plenty of good ideas and suggestions here.

as I often post , there really is no perfect answer for tranny cooling hook-up.

Your local weather will affect what type of cooling / warming you need in an aftermarket application: hotrod , race car, street machine, farm vehicle.

Liquid to liquid coolers offer the best heat transfer. Air to liquid function well, but MUST have air flow to operate.

I am not a fan of the coolers that "radiate" heat and are usually mounted to the frame member of the vehicle.... <---- read that as my opinion.

carry on the good discussion
 
#44 ·
Thanks for posting Crosley, and coming from the main source of valuable information I recieved when building my first 60e, I take your information as being experienced and very reliable.
Crosley said:
Your local weather will affect what type of cooling / warming you need in an aftermarket application: hotrod , race car, street machine, farm vehicle.
Now about my John Deere... :D
 
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