ATF Auxiliary Transmission Cooler

[dlduscg]

Has anyone tried to connect a B&M 70264 cooler in series with radiator cooler in 99 Q using the connectors in the kit provided? I think there's something missing. Radiator is 5/16 to cooler 3/8 and install instructions wacky.

[maxnix]

If you got it from Summit Racing, everything should be there.

It's not high pressure so any petorleum resistant hose of the correct diameter should work.

[dlduscg]

That's what I thought, but looking at threads, if I remove the entire fitting from the rad, I don't see the threads matching metric vs standard, curious, did you bypass the rad cooler?

[dlduscg]

What about using 5/16 in hoses instead of the 3/8 provided. Only 1/16 in difference?

[maxnix]

Hoses are just clamped.

[dlduscg]

Thanks, but it feels a little loose..read the skibanes post on parallel connection vs series, and the best location of the cooler vs any other location, such as yours. The conclusion is that there is restriction in the tank cooler/heater, probably due to design (to warm fluid at cold startup), or possibly sediment in his radiator. Naturally fluid will take the path of least resistance, thru the new cooler thereby reducing the pressure. The questions I have are; is the increase in pressure caused by the series connection nominal and within the acceptable parameters, and is the reduced pressure in the parallel connection slowing down the flow thru the tank cooler/heater resulting in less effective cooling than can be obtained with the series connection, and the pressure below the parameters for efficient flow. I tend to believe that the engineers who designed it with the series connection considered both parallel and series, and for whatever reason, decided against the parallel set up. I'm going with the B&M instructions if for no other reason than warranty protection, and with your suggestion to locate the external cooler away from the ambient heat.

[maxnix]

Well, I just didn't want to add additional thermal load to the radiator.

I think Skibane also included an external filter like latter G50 set up, and his best solution was both the cooler and heat exchanger in parallel before the filter.

In FL, I would go straight to the new ATF cooler and skip the OEM tank one.

[elwesso]

Well, I just didn't want to add additional thermal load to the radiator.

I think Skibane also included an external filter like latter G50 set up, and his best solution was both the cooler and heat exchanger in parallel before the filter.

In FL, I would go straight to the new ATF cooler and skip the OEM tank one.

Agreed... The problem with the OEM heat exchanger is they can clog, but that was mainly a problem on older Q before they put the filters on!

Just add the cooler and dont think about it too much... You're doing the majority of help by just adding the cooler, and messing around with those other setups and worrying about placement really is insignificant in the grand scheme of things...

[Q45tech]

85% of all heat generated in an AT comes from the torque convertor. Large trucks with AT have a separate system for TC from the rest of AT to avoid the HOT ATF from damaging the AT clutches and seals.

Important to actually measure the hottest point in ATF chain [going into heat exchanger] to design a cooling system that is adequate.After all the ATF life is specified in PEAK F not cooled down average F in sump.

http://www.roscommonequipmentc...5.pdf

[Skibane]

As previously mentioned, the purpose of running ATF through both coolers is (1.) to minimize backpressure, and (2.) to get some ATF pre-heating from the engine coolant during cold-weather driving.

I've been toying with the idea of putting shut-off valves on the lines that feed the original in-tank cooler and the aftermarket one, so that ATF can be routed only through the in-tank cooler during the winter, or only through the aftermarket cooler for long summertime trips.

[qship96]

A little Rube Goldberg-ish!

[dlduscg]

Is back pressure an important issue, if it is within an acceptable range, whatever that is? I think we can agree that heat is important, and it would be interesting to see the temperature comparisons for the same connections. I have a new radiator, which may or may not be oem specific, wonder if that would show same results. I do think the external filter is a must, especially so you can see the condition of the ATF at any time, and take the necessary action before futher damage occurs.

[elwesso]

an important concept is that the transmission does not "suck" the fluid through the lines, but rather the pump PUSHES it through the lines...

I dont know why you guys are getting so caught up on this subject. Put the cooler in, and the details arent really that important.

[Skibane]

I dont know why you guys are getting so caught up on this subject. Put the cooler in, and the details arent really that important.

Well, that's easy enough for YOU to say, Mister I-don't-need-no-stinkin'-cooler-for-my-5-speed!

[qsiguy]

I'm in a warm climate and rarely have temps very cold, no snow, etc. I disconnected mine from the radiator, pulled the old filter and run it only through my B&M cooler mounted as you see pictured between the condenser and radiator, the lines were 5/16" (radiator not installed in photo).

[qship96]

Add a cheap {$15-25} inline Magnefine disposable filter in one of those lines and you are well protected.