I'm about to install an upgraded VB and I will also install a B&M external cooler. I was wondering if I should keep the stock diameter for the hoses (that should be around 3/8") or going for something bigger (1/2") without creating a pressure drop. Does anyone know what's the stock internal diameter of the hoses going from the automatic tranny to the stock cooler in the rad? my car is low right now and i don't fit to check by myself (I'm lazy too ). Thanks!

 

I have a B&M ATF cooler sitting in the garage with hoses attached - if you can wait till tomorrow I can check the size for you... or possibly the OEM hose sizes are in the FSM? I'll check that tonight if I have time...

 

Sure I can wait. Thanks man!

 

I measured the ID of the hoses... one is 5/16" the other is 3/8"... the problem is I don’t remember which is inlet and which is outlet... and it's been so long since I've had it on the car I'm not even sure why they are different sizes.

The hoses I’m referencing are the ones on my external cooler – I’m not 100% certain they are the same size as the OEM hoses.

I strongly suggest double clamping each line though - preferably one spring clamp and one worm gear clamp... my return line blew off when I downshifted on the fwy (I only had 1 worm clamp). I wish the radiator and trans had threaded connectors to be able to use AN fittings.

BTW, I couldn’t find any reference in the FSM.

 

Different sizes? That's strange... I'm going to have to go down my car to check this by myself. About the AN fitting there is actually one (EARLS) that convert from tubing to AN male or female thread. It's just a simple compression fitting that you can install in the tranny outlets. I believe you have to cut the bump in the tube and then install the fitting. Here is the link to FEMALE and for MALE

 

thanks for the links - but I think I'd be as nervous about using compression fittings as I am about single worm gear clamp... I don’t mind using them on the hose side - it's the radiator inlet and return that I'm concerned about... I thought about having them threaded, but I don’t think the material would hold up.

As for the 2 sizes, I cant remember if the hoses came with the B&M cooler or if I bought them separate (its been 2 or 3 yrs) - It's possible that the inlet and return on the rad are different sizes (but not likely).

I can’t get under my car right now either, it sits way too low and my entire intake and plenum are taken apart so I can’t move the car out to jack it up.

Sorry I couldn’t be of more help

 

btw - are you using the Transgo VB?... if so, how much did you pay for labor to put it together (if you dont mind me asking).

 

I don't mind the compression fittings, they are very reliable; what i don't like is the cutting of the tranny tubing to use them. For the rad side there is barbed fitting that can be thread into the cooler inlet and outlet that should be reliable. With this I'm referring to an external cooler totally bypassing the stock rad.
In reference to the VB, I just purchased an already upgraded VB by SPG used from another member in this forum. I think this shop uses the Transgo kit.

 

oh, I didn’t realize you were omitting the OEM cooler... I ran mine in parallel with the OEM cooler (after the cooler)... so the lines went from trans to rad to external cooler and back to trans.

Is there a specific reason you don’t want to run it through the OEM cooler and the B&M?

 

None at all. The only concern I have with no bypassing the rad is for the bends of the hoses from the back of the rad to the front of it where the cooler will go. At the beginning I was considering replacing the regular rubber hoses with SS braided but I don't think is worth the trouble and money.
let me ask you something: do you know if VBs are interchangeable from a coupe 2005 to a sedan 2004? I'v been looking all over the net for parts numbers but i haven't found any info.

 

I'm not sure about the 05 to 04... coupe to sedan I dont think would be an issue but I know mid 04 there were some changes - for the trans I think it was only the TCM going internal, I suppose its possible the vb could be different but I dont know for sure... if its a late 04 then it has the changes that 05 has.

Have you tried calling Infiniti dealer the see if the part numbers are the same?

 

did you have a chance the check the ID of the OEM hoses?

 

I guess I'm not the only one that told the op the exact same thing.

 

I called an Infiniti dealer and they check VIN numbers for each car. 2005 coupe showed 4 VB with different part numbers in the same year; the 2004 sedan showed 3 different ones in 2004 model. The VIN for the coupe gave part number: 31705-AC808 and the VIN for my sedan gave part number: 31705-AC303. As you can see the first set of numbers are the same but the numbers after the dash varies. Now, the question is what represent the second set of numbers? Is just calibration options, different settings or just Infiniti stupidity?

 

No, i haven't but i beleive that 3/8" will be enough. Tha's the size i'll be using when installing the cooler.