Which Coolant Hoses are Handed?

[PeterW]

I'm getting ready to replace my old coolant hoses. Six were replaced recently during a TB/WP service, and I'm making a list of what I need to replace the rest. I found this helpful article on NSXPrime https://www.nsxprime.com/wiki/Coolant_hoses. I am aware that some of the hoses are handed (RHD vs LHD), so I can't just take the list off Prime. I'm buying the parts in the US, so I do need to make sure I order the right ones! As far as I can work out, there are just two hoses around the water valve which are handed, but I'm not 100% sure. The parts list doesn't make it completely clear. This is what I think the situation is:

79721-SL0-010 is RHD and 79721-SL0-A00 is LHD
79726 -SL0-000 is RHD and 79726-SL0-A00 is LHD


Can anybody confirm if this is right or wrong?

Also, is there anything against re-using the old clamps?

Thanks
Peter

[Kaz-kzukNA1]

Hi, Peter.

The coolant hose is year model/model spec/DBW/non-DBW/MT/AT/RHD/LHD dependent so you need to be bit careful.

Based on your userID, I think I know who you are and if my assumption is correct, the 6 hoses already replaced were;
3 x under the header tank
2 x at the oil cooler
1 x under the centre floor, cranked shape one.
These are marked with comment in the list below.


The first 5 digits in red are the ones sided (RHD/LHD).


If you know the history and the condition of the hose clamps, you may be able to re-use them but if you are thinking of using them for another 10 – 15 years, just replace all of them.
Not worth taking the risk of re-using the potentially corroded and weakened spring tension ones.

Also, there are 6 x pre-set clamp (probably 4 of them already replaced on your NSX) that are used on purposely for a reason and you are better off replacing them.

Please adjust the number of the clamps to be ordered as I believe on your NSX, some of them were already replaced in the past especially the ones at the 6 hoses already replaced.

Also, there are several parts such as the Figure of '8' o-ring that may have already been replaced on your NSX so please study the list carefully.


I posted the list for RHD NA2 in the past for Geoff so I'll just copy and modify it to suit your spec.


++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++
This is only for 95 - 96 model, RHD, NA1, DBW, MT & AT.
Please note this is not for 95 NA1 Type-R as it's non-DBW.

The list may not be suitable if you have any modifications from the factory spec on any part of the car.
For example, if you have the aftermarket header, bonnet/hood, super/turbo charger, removed the engine bay cover, etc, some of the parts in the list may not be suitable for the purpose without the extra parts/protection/process.


*** Radiator ***
(Koyo Rad, V2032)
(bolts for cooling fan shroud)
(spare rubber seal from Mazda/Toyota)

*** Coolant Hose, RHD, 95 - 96 only, NA1, DBW, MT, AT, except NA1 Type-R ***
19103-PR7-A00 x 1
19104-PR7-A00 x 1
19107-PR7-A00 x 1
19501-PR7-000 x 1
19502-PBY-R00 x 1
19506-PR7-A01 x 1 under the header tank
19507-PR7-A01 x 1 under the header tank
19518-PR7-A00 x 1 under the centre floor, cranked shape
19519-PR7-A00 x 1
79721-SL0-010 x 1
79722-SL0-A00 x 1
79725-SL0-A00 x 1
79726-SL0-000 x 1
79727-SL0-A00 x 1
79728-SL0-A00 x 1 under the header tank
19422-PR7-A01 x 1 oil cooler
19423-PR7-A00 x 1 oil cooler
19424-PR7-A00 x 1
19522-PR7-J00 x 1
xxxxxxxxxxxxxxxxxxx 19523- not required.
19524-PR7-A00 x 1
19526-PR7-A00 x 1

For AT only, add these 2 hoses;
19429-PR7-A10 x 1 AT only
19430-PR7-A10 x 1 AT only


*** Figure of ‘8’, rad drain/bleeder o-ring, aluminium gasket ***
91318-PY3-000 x 1 removing the oil cooler for replacing 2 hoses
19012-PD2-004 x 2
90471-580-000 x 2


*** Cap, header tank, thermostat ***
19045-PR7-J24 x 1
19101-PR7-A02 x 1
19301-P8E-A10 x 1


*** coolant hose clamp ***
Some can be re-used if you know the original condition.
If not, replace them.
Not worth the risk.

19511-PR7-A01 x 12 　　big one
19512-PC6-003 x 2 (x 6 for AT) low tension
19513-PE0-003 x 12　　high tension
90661-SL0-A01 x 6　　　pre-set type
95002-4125004 x 8　　 small one
95002-70000 x 1　　　　 overflow tube


*** Honda Type-2 coolant ***
08CLA-G01-8L0 x 3

You will need about 16.2 - 16.5L minimum.
Although each container comes in 5L size, it actually holds about 5.45L.

Honda Type 2 is pre-mixed at 50% and recommended to be replaced every 5 years but from what I saw on many WP including mine, best replaced every 4 years or earlier if it was not factory filled.
You can use distilled water and bring it down to 30% and replace every 2 years if you track your NSX regularly.


*** lots and lots of silicone/rubber grease + time ***


Kaz

[PeterW]

Hi Kaz,

Thanks for your, as ever, comprehensive reply. Thanks also for taking the trouble to go back into your records of the service you did on my NSX. It's not that straightforward creating the parts list for this job, so your reply to my post is very much appreciated.

Peter