bellwilliam wrote:I think there is a misconception here that by doing the bypass, you might overheat the transmission. it is the other way around. w/o bypass, transmission warm up FASTER.

if you really are concerned about heat. just install another transmission fluid cooler, it is pretty simple. not much to it. and cost may be 1 hour of labor and $100 for parts.

I don't think there's a miconception at all. As I understood pawjr74's post, it seemed he was asking if the warning light could be an indicator of coolant contamination. OTOH, maybe I simply read something into it that he didn't intend.

Sorry for the confusion, I just was wondering if there was a warning system in place if the bypass was done to keep an eye on overheating. I did not mean for coolant contamination.

just bought a 08 PF and will be doing this bypass ASAP.

What the difference between the two versions mentioned in this thread. The "3/8" double ended barbed hose connector" method and the other "free - move hoses" method?

Would you also recommend a tranny fluid drain/ refill and (if applicable) a filter change? I'm new to these Pathfinders.... not sure if the trans has an external filter or internal?

TB - your '08 is going to be a little different. The auxiliary cooler on the '08s are on the driver's side instead of the passenger's side like the '05-'07. The hoses are routed different. The return is still on the passenger side, but the inlet line runs through the radiator cooler, then around the driver's side to the auxiliary cooler.

There's no filter change with a drain/refill. Just use the drain plug. I've looked in the FSM about a filter, but see no reference. In a diagram, it has what looks like a screen, similar to the C6 in my Ford. There are two magnets on the bottom of the pan to pick up shavings.

Went to the dealer and asked for a transmission filter since i am doing the flush, to try to get rid of contamination already in my pathfinder....dam radiators, but no filter is required, there is just a screen like datsun08 says.

I will (finally) be doing this mod on Saturday along with installing HID's that came in the mail this week.

08Datsun wrote:TB - your '08 is going to be a little different. The auxiliary cooler on the '08s are on the driver's side instead of the passenger's side like the '05-'07. The hoses are routed different. The return is still on the passenger side, but the inlet line runs through the radiator cooler, then around the driver's side to the auxiliary cooler.

There's no filter change with a drain/refill. Just use the drain plug. I've looked in the FSM about a filter, but see no reference. In a diagram, it has what looks like a screen, similar to the C6 in my Ford. There are two magnets on the bottom of the pan to pick up shavings.

would the method of using the hose connector then capping off the nipples on the rad be any different on my model?

i'll use this method as i don't see any down sides since there is an auxiliary cooler

I looked through the service manual yesterday, and there is an ATF temp sensor and a DTC code (P1710) associated with it. I haven't looked through the logic in detail, but overtemp situations should fire the check engine light and throw a code.

Looking at the (engine coolant) thermostat temperature settings (177-182 F) vs operating temp of the transmission fluid (176 F, indicated in the service manual), they are very close. While the temp of ATF going to the radiator could be higher than sump temp, I'm getting more comfortable that the radiator cooler does not contribute significantly to ATF cooling at operating temps. (Since both sides of the heat exchanger are probably running at similar temps during operation.)

I did the bypass about a month ago and all has been normal. Now Im reading the proactiveness of some of the guys here and how they used the tranny cooler flush tool from Nissan. I figured I could just do the bypass and boom, done! Now Im wondering, should I go back and do the flush...When I did the bypass about 1/4 to 1/2 a cup of fluid came out that looked fine. No strawberry milk shake here...Should I just leave it alone? Or go back and do the flush...

rooch wrote:I did the bypass about a month ago and all has been normal. Now Im reading the proactiveness of some of the guys here and how they used the tranny cooler flush tool from Nissan. I figured I could just do the bypass and boom, done! Now Im wondering, should I go back and do the flush...When I did the bypass about 1/4 to 1/2 a cup of fluid came out that looked fine. No strawberry milk shake here...Should I just leave it alone? Or go back and do the flush...

I wouldnt worry about it. I did mine a couple months ago and I didnt flush out the cooler either.
Keep in mind that by bypassing the internal cooler, you have eliminated fluid pressure from one side. You dont have coolant and trans fluid heat and pressure on both sides anymore. If it does start leaking, the small amount of trans fluid left is minimal... I dont imagine it is enough to turn your cooling system into a milk shake.

trailblaze wrote:

08Datsun wrote:TB - your '08 is going to be a little different. The auxiliary cooler on the '08s are on the driver's side instead of the passenger's side like the '05-'07. The hoses are routed different. The return is still on the passenger side, but the inlet line runs through the radiator cooler, then around the driver's side to the auxiliary cooler.

would the method of using the hose connector then capping off the nipples on the rad be any different on my model?

i'll use this method as i don't see any down sides since there is an auxiliary cooler

You may or may not need some extra hose due to the different routing is all I was getting at. The components are the same.

Any thoughts on replacing the factory external trans cooler with this one?



B&M Hi-Tek Automatic Transmission Cooling System 13-1/2"x9"x3-1/2" with 9-1/2" diameter fan

"The newest addition to B&M's line of SuperCooler fluid coolers is the Hi-Tek cooling system. Fitted with a high quality 12 volt electric fan and built-in mounting brackets, these coolers handle tough cooling jobs. They include a thermal switch to activate the fan when the fluid temperature reaches 175 degrees F. Can be used for racing, RV and street performance vehicles. Suitable for all fluid cooling needs including: automatic transmission fluid, engine oil, differential fluid, power steering and tubrocharger oil in circle track, road racing, off-road, tractor pulling and monster truck applications."

http://www.bmracing.com/PRODUCTS/Hi-Tek ... ameter-fan#

pawjr74 wrote:Any thoughts on replacing the factory external trans cooler with this one?



B&M Hi-Tek Automatic Transmission Cooling System 13-1/2"x9"x3-1/2" with 9-1/2" diameter fan

"The newest addition to B&M's line of SuperCooler fluid coolers is the Hi-Tek cooling system. Fitted with a high quality 12 volt electric fan and built-in mounting brackets, these coolers handle tough cooling jobs. They include a thermal switch to activate the fan when the fluid temperature reaches 175 degrees F. Can be used for racing, RV and street performance vehicles. Suitable for all fluid cooling needs including: automatic transmission fluid, engine oil, differential fluid, power steering and tubrocharger oil in circle track, road racing, off-road, tractor pulling and monster truck applications."

http://www.bmracing.com/PRODUCTS/Hi-Tek ... ameter-fan#

It looks the same as what is in the truck already, but with a fan on it. Wonder what the power draw of the fan is.

looks like a nice cooler.....
where would you put it, and how would you mount it?

That's my dilema. I am trying to come up with a mounting location or even possibly just replace the factory external cooler. I like that the fan kicks in at 175 degrees. I'm going to look into this some more.