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Hi All,

Since I'm looking at doing a radiator change, was thinking should do the hoses at the same time.
I have an NA8 1.8L Engine in my NA6, just wondering how many hoses and which kit I should get?
Some seem to have 3 hoses, some have 6, 9 and even seen an 11???

Thanks in advance
Rod.

Kevlar reinforced ones from MX5parts.co.uk, cheaper than OEM, not as garish as silicone.

1red5 wrote:Kevlar reinforced ones from MX5parts.co.uk, cheaper than OEM, not as garish as silicone.

This.
From memory I bought the 1.8 kit for my BP engined NA6.

x3 for kevlar reinforced rubber. NA8 hoses are:

Big hoses:
- Radiator top hose
- Radiator bottom hose
- Water pump inlet (= extension of bottom hose)
Middle sized hoses:
- back of head to heater
- heater to water pump extension tube under exhaust manifold
Small hoses:
- water pump to thermostat extension
- thermostat extension to throttle body
- throttle body to oil filter/cooler
- oil filter/cooler to back of head

The last one, the invisible unreachable little one from the oil filter to the back of the head, is the one that always fails in the dark far from home.

Is there anything to look out for when changing hoses?
I was planning to do this while changing the radiator, so coolant should not be an issue.
Is there any other fluids which will be in any of the hoses that I should be aware of?

Thanks
Rod

Normally nothing dangerous. Be careful taking the 2 heater hoses off. The pipes through the firewall into the heater core are weak. You should cut them off with a knife rather than try to pull and twist them off.

Look out for crustiness inside of the hoses you remove, but if you are replacing radiator at the same time it shouldn't matter too much. Also, look for oil in the coolant. Again, shouldn't be an issue, but if you see it you might have a headgasket issue.

While you are changing hoses, you should probably change the thermostat as well, as having it high and dry (after being immersed) generally makes it stop working in my experience (lost two to this)

Would you replace good hoses? Mechanics normally only replace hoses that are showing signs of deterioration. Read a service manual - refilling can be tricky. Bursons should be able to quote compatible hoses and supply quickly- benchmark against Mazda etc. Conventional hoses last a very long time.

Some of the hoses are looking a bit old, my car is an 89, the engine came from a 97.
Was all built and done in 2006, but car was then left in storage for the last 6 years.
It has dríven around 100Km's in that time so was thinking since changing the radiator it would be a good time to fix up any other things. Plan on driving it more now I have a Cat and Resinator and sounds descent on the streets

Who is Bursons?

Thanks
Rod

Bursons are generally ridiculously expensive, because they have so much stock on hand. They're good if you desperately need a part, but you pay for it. The cheapest option will def be through the net.

It's usually good insurance to replace the lot on an older car when you don't know the history. Hoses fail when you least need it - usually a track day or a long trip. The cost of a set is a helluva lot less than the cost of getting stuck in the middle of nowhere. I'd say I've seen a couple of dozen blown hoses at track days. NA6s are getting on a bit. The little ones under the NA8 inlet manifold are a right prick to fix when everything's hot.

Buying individual pieces from auto stores is expensive and you don't know the quality. The 6 piece kevlar set through the net is the cheapest way and gives you the best quality as well, as long as you get made in UK ones. The 3 hoses missing from the set are the little ones from the thermostat housing to the back of the head. These can be cut from bulk hose from Repco or anywhere like that. I think it's 1/4" hose and must be coolant hose, not vacuum, so just a little hard to find. If you can't find the hose then you'll just have to get OEM from Mazda. Virtually no one else sells them.

You might have a small problem with an NA8 engine in an NA6. The NA8 set uses 2 pieces with a section of alloy pipe between them to get from the bottom of the radiator to the pump inlet. The NA6 uses one long convoluted hose along the same path. I'd suggest getting the NA8 set and finding or improvising that joiner. If you get the NA6 set then I think you'll have the wrong top hose. Can someone confirm that?

I can confirm NA8 BPE8-15-186 & NA6 B61P-15-186 top hoses are different, not only the part numbers but the shape.

You'll also need to factor in if you're still using the NA6 top radiator pipe & the NA6 air intake cross pipe, as it dips under the NA6 top rad pipe, whereas the NA8 cross pipe goes over the NA8 top rad pipe.

Maybe buy a set of each and sell all the surplus bits here?