I have noticed a hard-line that runs behind the tank and parallel to the rear bumper and loops back that seems to connect to the rear diff cooler. These are very rotten at a point on my Z.

Can anyone advise on what the purpose is of these and whether I can just bypass the rotten looping hard-line? I don't have great access under the car in my garage so I cannot trace all the diff lines easily. I'm also finding UK spec specific diagrams, etc the usual challenge too!

The looping hardline in question:

Rotten:

Can I safely bypass here:

Edited February 13, 20223 yr by Peage

The loop is in series with the diff oil cooler. There is no explanation in the FSM as to the purpose other than the line is described as

"TUBE ASSY-DIFFERENTIAL OIL COOLER" in the parts system. The whole diff cooler sysem was introduced by Nissan after very high

speed runs in Germany and is largely redundant for normal driving conditions. This is the FSM page for the UK/Euro spec cars which

have it fitted (click image for better res). I can't see why you couldn't do as you suggest and bypass the loop.

BTW you appear to be missing the bumper fixing clips that fix the bumper tabs to the chassis in your pictures above (link for ref):

https://conceptzperformance.com/nissan-infiniti-nissan-oem-rear-bumper-fastener-nissan-300zx-z32-85071-30p00_p_6114.php

 

 

Edited February 13, 20223 yr by AndrewG

Wow, you have a physical UK FSM? Well done getting that. ? 

That diagram is perfect too - just what I was after. Thank you for digging that out for me Andrew!

...and for the tip about the missing clips too! I'm about to do a parts order so that's handy to know.