Na1 expansion tank

[marknsx]

Leak. If the tank is split a new one will cost £250 plus. I think the leak is from the top valve attached to the rubber hose. Not the hose. The leak isn't bad just a very small amount of fluid on the top and side rim. Is there a way of testing for splits?

[L696ULO]

Hi Mark
Are you referring to the coolant expansion tank (which are prone to splitting sometimes after a few years) ?
They tend to split where the two halves are joined and mine dripped a tiny amount of coolant on the hose below which could confuse where the leak is coming from.
i contacted Vtec direct (in the vendors section) and they sent a Oem to me for about £80 from memory, it was 3-4 years ago but worth giving them a call if you find out the leak is from the tank.

[marknsx]

Lovely I will contact them

[Kaz-kzukNA1]

You can always pressure test the system but the most common place for the header/expansion tank to leak is at the brass neck where the tank cap sits and the bonding section between the upper and lower tanks.

Unfortunately, since several years ago, even with the new tank, it could start leaking within 1 year even after taking care of how to install it.
On NSX Prime, I even saw one owner claiming that it started leaking within just a few months….
You could claim it under warranty if it was bought within UK and within 12 months.

If interested, I touched on the structure of the header tank and why you want to stay with OEM one in the following links;
http://www.nsxcb.co.uk/entry.php?1321-OEM-Coolant-Header-Tank

http://www.nsxcb.co.uk/entry.php?1422-OEM-Header-Tank-02 (http://www.nsxcb.co.uk/entry.php?1422-OEM-Header-Tank-02)

http://www.nsxcb.co.uk/entry.php?1423-OEM-Header-Tank-03 (http://www.nsxcb.co.uk/entry.php?1423-OEM-Header-Tank-03)


By the way, please double check the tank cap and the cap rubber gasket as well.
If your cap is brass colour, then it was never replaced in the past and question mark on the spring fatigue.
The rugger gasket would be very likely to be cracked in many places by now.
Not good if you can’t keep the specified pressure.


With the current exchange rate, if you can get the replacement tank under GBP95 - 100 with JP delivery/UK Customs/ParcelForce fee included, then that will be a good deal.

Kaz

[marknsx]

Kaz
I have had a closer look at the leak. I have replaced the original cap which was definitely partly perished with a new one. Still have a leak. Sure it's now coming from the brass neck at top of tank. Seems to have been sealed in the past. An old sealant is coming away from the join of brass and plastic.

[marknsx]

There appears to be no way of resealing the neck of the tank around the brass fitting. So I need a replacement. Any thoughts on a reliable outlet?

[marknsx]

so the advice is replace with OEM. This I have asked my local dealer to do. Interestingly its a 2 day turn around from order and cheaper than 2 others that i have sourced.
Thanks again to Balmer Lawn Honda. Great bunch!!