Transmission Coolant Bypass Write Up?

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paradigm
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Transmission Coolant Bypass Write Up?

Postby paradigm » Thu May 03, 2018 11:19 am

Is there a go-to writeup or should I just use any old one I find on search to do the transmission coolant bypass mod?

I found this one, but wondering if there is a better one?

http://www.clubfrontier.org/forums/f23/ ... ass-42555/


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smj999smj
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Postby smj999smj » Thu May 03, 2018 11:52 am

My personal opinion, for what it's worth, is that it's better to replace the radiator with an aftermarket and maintain the use of the radiator's integral cooler than bypass, but, that said, there are plenty of people who have bypassed and utilized the auxiliary cooler without any issues.

As far as the bypass method, the way you do it depends on your year. On 2005-2007 models, the auxiliary cooler was mounted on the passenger side and is the easiest of the two to bypass. It's a simple remove the short hose on the right side, re-route, cap ends and tighten clamps. The 2008-2010 models had the auxiliary coolers mounted on the driver's side, so usually the line on the driver's side of the radiator is disconnected at a union and a new section of 5/16" (8MM) transmission cooler hose is run from the union to the line on the passenger side, as opposed to just re-routing the hoses on the earlier models. They probably cover both in the link you provided, but I just don't have time to go through all 23 pages of it!

As far as 2011-2012 models, they weren't affected.

paradigm
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Postby paradigm » Thu May 03, 2018 11:58 am

smj999smj wrote:My personal opinion, for what it's worth, is that it's better to replace the radiator with an aftermarket and maintain the use of the radiator's integral cooler than bypass, but, that said, there are plenty of people who have bypassed and utilized the auxiliary cooler without any issues.

As far as the bypass method, the way you do it depends on your year. On 2005-2007 models, the auxiliary cooler was mounted on the passenger side and is the easiest of the two to bypass. It's a simple remove the short hose on the right side, re-route, cap ends and tighten clamps. The 2008-2010 models had the auxiliary coolers mounted on the driver's side, so usually the line on the driver's side of the radiator is disconnected at a union and a new section of 5/16" (8MM) transmission cooler hose is run from the union to the line on the passenger side, as opposed to just re-routing the hoses on the earlier models. They probably cover both in the link you provided, but I just don't have time to go through all 23 pages of it!

As far as 2011-2012 models, they weren't affected.
Cool, Ill need to get some 5/16" vacuum caps and some new 5/16" transmission cooler hose then.

I am going to bypass temporarily until I get my radiator replaced under warranty (I have a tech at Nissan in the Toronto area of Canada that says he will do it for me when I visit in May - the truck is also originally from the Toronto area). I am thinking that rad should be good.. or is it best not to trust anything from Nissan?

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smj999smj
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Postby smj999smj » Thu May 03, 2018 12:01 pm

Any of the current replacement radiators from Nissan are fine and haven't had issues.

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Postby paradigm » Thu May 03, 2018 12:13 pm

smj999smj wrote:Any of the current replacement radiators from Nissan are fine and haven't had issues.
Great. So in the short term I will do the bypass mod for peace of mind until I get the rad replaced.

Thanks

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underworld1001
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Postby underworld1001 » Fri May 04, 2018 9:43 pm

If you do the bypass, make sure that the clamps are tight. Not snug, but tight.

Case in point, I did the bypass and drove 320 miles before I stopped for gas about 1-2 minutes from my parents place. Tried to drive off and the engine just revved and then BAM, the truck jumped forward and started accelerating like normal. Looked under the car and saw some red fluid dripping out when I made it to my parents and worked on it the next day. So yeah, make sure the connections are tight.

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Postby paradigm » Sun Nov 04, 2018 6:02 am

Guys, sorry to bump this thread again.

Any more clear instructions on how to do the bypass mod for a 2008-2010 Pathfinder 4.0L?

Thanks

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Postby eieio » Sun Nov 04, 2018 7:07 am

paradigm wrote:Guys, sorry to bump this thread again.

Any more clear instructions on how to do the bypass mod for a 2008-2010 Pathfinder 4.0L?

Thanks
http://www.thenissanpath.com/viewtopic. ... ght=bypass

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Postby paradigm » Sun Nov 04, 2018 9:37 am

eieio wrote:
paradigm wrote:Guys, sorry to bump this thread again.

Any more clear instructions on how to do the bypass mod for a 2008-2010 Pathfinder 4.0L?

Thanks
http://www.thenissanpath.com/viewtopic. ... ght=bypass
41 page thread, I skimmed through but didn't see something specific to the 2008-2010 model

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Postby paradigm » Sun Nov 04, 2018 9:47 am

OK from the thread linked above I grabbed these instructions from smj999smj for the 2008-2010 models.


Materials:
• two feet of 5/16" (8MM) transmission cooler hose
• some miniature hose clamps
• a plastic tie strap
• two, 5/16" caps.
• ATF - a quart of Nissanmatic Type "J" or "S" ATF or equivalent (Castrol Transmax Import Multi-vehicle or Valvoline Maxlife ATF) just in case.
Steps:
1. Remove the front skid plate.
2. If you look at the cooler hoses, there is a left and right side hose (left being the driver's side). The left hose goes from the radiator cooler fitting to a metal hose union at the left side of the radiator.
3. Remove the cooler hose from this union and from the radiator fitting.
4. Remove the right side hose from the radiator fitting to the metal cooler line.
5. You can blow clear or flush the radiator's cooler if you wish to remove the trans fluid from the cooler.
6. Install the two caps on the radiator's fittings and install/tighten clamps.
7. Install the new cooler hose to the union at the left side of the radiator and clamp.
8. Run the hose to the metal line and cut to size, install and clamp.
9. Use the plastic tie strap to secure the hose so it's not flopping all around.
10. Clean off the residual oil. Start the vehicle, top of the ATF and check for leaks. If all is good, reinstall the skid plate.

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Postby paradigm » Sun Nov 04, 2018 11:04 am

Who wants to do my bypass mod in the NYC area? I absolutely suck and cannot figure this out.

On the left side (driver side) of the radiator, I see the cooler. There is ONE hose coming out of the cooler and it enters the bottom of the radiator.

On the right side of the radiator there is ONE hose coming from the bottom of the radiator going to a metal line connection where multiple hoses are connected to, which i assume some lead back to the the transmission.

I have no idea what to connect to what because all of what I see does not align with the instructions on any of the threads.

2010 Canadian 4.0L V6 rustbox

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Postby palmerwmd » Mon Nov 05, 2018 4:59 pm

Its one of those things thats easy in theory... but for someone who doenst deal w/ vehicles on a regular basis it can be daunting.

No matter where you are any shop should be willing to do it for a reasonable fee.

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Postby paradigm » Mon Nov 05, 2018 5:57 pm

Can someone tell me where the hell I am going wrong here? I went under the truck and I saw a line leading from the junction on the bottom passenger circled in red, back to the transmission:

Image

Then i saw a line leading from the bottom driver side of the radiator leading up to the cooler, circled in blue:
Image

I circled those same spots on this diagram here:
Image


Am I supposed to remove the line I highlighted in purple, and then run a line that I highlighted in green?
Image[/img]

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smj999smj
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Postby smj999smj » Wed Nov 07, 2018 4:41 pm

Basically, to simplify it, you're disconnecting the hoses from the red circle and blue circle and running a new section of hose between the hoses, eliminating the radiator from the loop. So, remove both hoses from the radiator fittings and cap the fittings on the radiator with 5/16" vacuum caps and clamps. If you look on the driver's side of the radiator from under the vehicle, you will see the line has a metal union and two clamps. So, you can remove the bottom hose from that union (which is the hose that goes to the left radiator fitting) and discard the hose (or save in case you ever want to replace the radiator and undo the bypass). There is a hose that goes from the right radiator fitting to the metal cooler line; remove and discard that hose. Get about 2' of 5/16" transmission cooler hose (cut to size needed) and install it from the metal union on the left side of the radiator to the metal trans cooler line where you disconnected the old hose. Obviously, you are going to install clamps on that new section of hose. Pre-2008 Pathfinders are even easier because the cooler is on the other side and you don't need to purchase a new section of hose.


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