Transmission Fluid Flow Rate through Radiator problem?

Ray O wrote:
> > wrote in message
> oups.com...
>>>
>>> I do not recall ever seeing a specification
>>> fortransmissionfluidflowrate through theradiator. Theflowratewill
>>> vary depending on pump output. I would see if the coolant
>>> temperature drops after it exits theradiatorand cooler.
>>> --
>>>
>>> Ray O
>>> (correct punctuation to reply)
>>
>> Thanks Ray O,
>> Tranny shop said they tested t-fluid flow with "operating temp" fluid
>> using the same RPM's for three flow tests;
>> 1) just tranny which produced 3 quarts in 30 sec.
>> 2) tranny and aux-cooler which also produced 3 quarts in 30 sec.
>> 3) tranny and radiator which produced just 1 quart in 30 sec.
>>
>> Do not know if they had a measured both the in and out temps... will
>> ask.
>>
>> Have to presume their logic is.... if there is a restriction or fault
>> in the radiator flow then the t-fluid will not cool... especially
>> when the tranny wants a 3 quart rate.
>>
>> Thx
>> Dave-in-Denver
>>
>
> If that is the case, then there is a problem in the radiator. The
> transmission part of the radiator may have been rebuilt incorrectly,
> the cooling fins are obstructed so that sufficient air does not flow
> through them, or something has clogged the cooler part internally.

???

Cooling fin damage or obstruction will not affect the flow rate through the
unit.

> This sounds high for a tranny at idle. Nominal flow rate would depend
> a lot on trany size and isle speed and oil cooler line size to. If you
> are really worried you could install a pressure gauge on tranny line
> in a "Tee" to test it. Check pressure before cooler and after and if
> there is a restriction in cooler you will see a big pressure
> differentail.
> -----------------
> TheSnoMan.com

Thx SnoMan,
I sure hope the tranny shop owner has enough smarts to test flow at an
RPM that is above idle... but you never no so I will ask.

Also... I like your idea (and others?) to actually check the pressure
coming out of the tranny and not just observing the rate of flow.
Will ask about this too.

Thx
Dave-in-Denver

> If that is the case, then there is a problem in the radiator. The
> transmission part of the radiator may have been rebuilt incorrectly, the
> cooling fins are obstructed so that sufficient air does not flow through
> them, or something has clogged the cooler part internally.
> --
>
> Ray O
> (correct punctuation to reply)

Thanks Ray O,
Yep... it sure points to a clog of some kind.

When I called Toyota... they had not tech info on t-fluid flow rate
through the radiator.

But one thing is clear... the radiator is sure slowing down the flow
and that can not be good.

Thx
Dave-in-Denver

On Jun 13, 6:32 pm, SnoMan > wrote:
> On Wed, 13 Jun 2007 16:08:29 -0700, wrote:
> >Aux cooler was picked out by tranny shop... it looks smaller than what
> >I would have picked out... so my guess is that the tranny shop follows
> >your advise too and does not over do it on aux size.
>
> One tip here on aux cooler, make sure it is routed so fluid passes
> through radiotr core tube and then aux cooler, not the other way
> around and not bypassing tank cooler completely either.
> -----------------
> TheSnoMan.com

Hi SnoMan,
Well that is a good tip.

I was considering asking the tranny shop to skip the radiator (due to
its poor performance) and just use the aux cooler.

Why not just aux cooler... is it because there is no fan or is it a
simple volume thing. FYI... my aux cooler is down on the skip
plate... no room (they said) to double up at the radiator.

Thx
Dave-in-Denver

On Wed, 13 Jun 2007 18:13:49 -0700, wrote:

>Why not just aux cooler... is it because there is no fan or is it a
>simple volume thing. FYI... my aux cooler is down on the skip
>plate... no room (they said) to double up at the radiator.


There is a couple of reasons. First water can take a LOT more heat
from oil than air if coolant is cool and it also help stabile the oil
temp and warm tranny up because heater recirculates water through tank
where cooler is. Next is if you do bypass it you will reduce
effectiveness of your A/C some because it dumps hot air on condensor
so it cools it less. Logically to get best cooling for it you want the
oil to be pre cooled in radiotr then cooled a bit more in aux cooler
with throwing all the heat into A/C condensor. When routed in seris
like that the aux cooler does not dump as much heat on AC and it also
acts as a safty net should engine overheat, tranny still gets cooled.
-----------------
TheSnoMan.com

> There is a couple of reasons. First water can take a LOT more heat
> from oil than air if coolant is cool and it also help stabile the oil
> temp and warm tranny up because heater recirculates water through tank
> where cooler is. Next is if you do bypass it you will reduce
> effectiveness of your A/C some because it dumps hot air on condensor
> so it cools it less. Logically to get best cooling for it you want the
> oil to be pre cooled in radiotr then cooled a bit more in aux cooler
> with throwing all the heat into A/C condensor. When routed in seris
> like that the aux cooler does not dump as much heat on AC and it also
> acts as a safty net should engine overheat, tranny still gets cooled.
> -----------------
> TheSnoMan.com

Pro info.
Thanks SnoMan.

Dave-in-Denver

"Commentator" > wrote in message
.. .
> Ray O wrote:
>> > wrote in message
>> oups.com...
>>>>
>>>> I do not recall ever seeing a specification
>>>> fortransmissionfluidflowrate through theradiator. Theflowratewill
>>>> vary depending on pump output. I would see if the coolant
>>>> temperature drops after it exits theradiatorand cooler.
>>>> --
>>>>
>>>> Ray O
>>>> (correct punctuation to reply)
>>>
>>> Thanks Ray O,
>>> Tranny shop said they tested t-fluid flow with "operating temp" fluid
>>> using the same RPM's for three flow tests;
>>> 1) just tranny which produced 3 quarts in 30 sec.
>>> 2) tranny and aux-cooler which also produced 3 quarts in 30 sec.
>>> 3) tranny and radiator which produced just 1 quart in 30 sec.
>>>
>>> Do not know if they had a measured both the in and out temps... will
>>> ask.
>>>
>>> Have to presume their logic is.... if there is a restriction or fault
>>> in the radiator flow then the t-fluid will not cool... especially
>>> when the tranny wants a 3 quart rate.
>>>
>>> Thx
>>> Dave-in-Denver
>>>
>>
>> If that is the case, then there is a problem in the radiator. The
>> transmission part of the radiator may have been rebuilt incorrectly,
>> the cooling fins are obstructed so that sufficient air does not flow
>> through them, or something has clogged the cooler part internally.
>
> ???
>
> Cooling fin damage or obstruction will not affect the flow rate through
> the unit.
I agree that cooling fin damage or obstruction will not affect the flow rate
through the unit, but it can reduce cooling capacity, which was the OP's
original problem.
--

Ray O
(correct punctuation to reply)

Ray O wrote:
> "Commentator" > wrote in message
> .. .
>> Ray O wrote:
>>> > wrote in message
>>> oups.com...
>>>>>
>>>>> I do not recall ever seeing a specification
>>>>> fortransmissionfluidflowrate through theradiator. Theflowratewill
>>>>> vary depending on pump output. I would see if the coolant
>>>>> temperature drops after it exits theradiatorand cooler.
>>>>> --
>>>>>
>>>>> Ray O
>>>>> (correct punctuation to reply)
>>>>
>>>> Thanks Ray O,
>>>> Tranny shop said they tested t-fluid flow with "operating temp"
>>>> fluid using the same RPM's for three flow tests;
>>>> 1) just tranny which produced 3 quarts in 30 sec.
>>>> 2) tranny and aux-cooler which also produced 3 quarts in 30 sec.
>>>> 3) tranny and radiator which produced just 1 quart in 30 sec.
>>>>
>>>> Do not know if they had a measured both the in and out temps...
>>>> will ask.
>>>>
>>>> Have to presume their logic is.... if there is a restriction or
>>>> fault in the radiator flow then the t-fluid will not cool...
>>>> especially when the tranny wants a 3 quart rate.
>>>>
>>>> Thx
>>>> Dave-in-Denver
>>>>
>>>
>>> If that is the case, then there is a problem in the radiator. The
>>> transmission part of the radiator may have been rebuilt incorrectly,
>>> the cooling fins are obstructed so that sufficient air does not flow
>>> through them, or something has clogged the cooler part internally.
>>
>> ???
>>
>> Cooling fin damage or obstruction will not affect the flow rate
>> through the unit.
> I agree that cooling fin damage or obstruction will not affect the
> flow rate through the unit, but it can reduce cooling capacity, which
> was the OP's original problem.

Gotcha.

Thought you were just commenting on the flow rate....

"Commentator" > wrote in message
...
> Ray O wrote:
>> "Commentator" > wrote in message
>> .. .
>>> Ray O wrote:
>>>> > wrote in message
>>>> oups.com...
>>>>>>
>>>>>> I do not recall ever seeing a specification
>>>>>> fortransmissionfluidflowrate through theradiator. Theflowratewill
>>>>>> vary depending on pump output. I would see if the coolant
>>>>>> temperature drops after it exits theradiatorand cooler.
>>>>>> --
>>>>>>
>>>>>> Ray O
>>>>>> (correct punctuation to reply)
>>>>>
>>>>> Thanks Ray O,
>>>>> Tranny shop said they tested t-fluid flow with "operating temp"
>>>>> fluid using the same RPM's for three flow tests;
>>>>> 1) just tranny which produced 3 quarts in 30 sec.
>>>>> 2) tranny and aux-cooler which also produced 3 quarts in 30 sec.
>>>>> 3) tranny and radiator which produced just 1 quart in 30 sec.
>>>>>
>>>>> Do not know if they had a measured both the in and out temps...
>>>>> will ask.
>>>>>
>>>>> Have to presume their logic is.... if there is a restriction or
>>>>> fault in the radiator flow then the t-fluid will not cool...
>>>>> especially when the tranny wants a 3 quart rate.
>>>>>
>>>>> Thx
>>>>> Dave-in-Denver
>>>>>
>>>>
>>>> If that is the case, then there is a problem in the radiator. The
>>>> transmission part of the radiator may have been rebuilt incorrectly,
>>>> the cooling fins are obstructed so that sufficient air does not flow
>>>> through them, or something has clogged the cooler part internally.
>>>
>>> ???
>>>
>>> Cooling fin damage or obstruction will not affect the flow rate
>>> through the unit.
>> I agree that cooling fin damage or obstruction will not affect the
>> flow rate through the unit, but it can reduce cooling capacity, which
>> was the OP's original problem.
>
> Gotcha.
>
> Thought you were just commenting on the flow rate....
My bad, yup, after re-reading my post, it does look like I was just
commenting on the flow rate...

Thanks for pointing that out!
--

Ray O
(correct punctuation to reply)

On Wed, 13 Jun 2007 13:50:24 -0700, wrote:

>My new transmission is (still) overheating on long highway drives.
>
>Transmission shop tested the t-fluid flow rate through the radiator at
>1 quart every 30 seconds.
>The transmission itself however will push times that amount, 3 quarts
>every 30 seconds, all by itself and also through an aux t-cooler.
>
>My radiator is only 2 years old. When I first started having
>transmission overheating I found the radiator was shot and had it
>replaced and later put in a tran cooler too.
>
>So the questions is...
>What should be the t-fluid flow rate through the radiator?

What transmission? The cooler flow rate is listed in the detailed
specifications. As well, there is a test described for some
transmissions (I can quote the 4L80E's test if anyone is interested).
Low flow in the cooler can lead to premature failure due to lack of
proper lubrication of some components.


>In other words... is my radiator restricting t-fluid flow rates below
>spec?

Perhaps... Again, without checking the 'book' you don't know.

>
>1993 4Runner, V6 3L, Auto, 4x4, 170K
>
>Thx
>Dave-in-Denver