Maintenance - Check those hoses and replace the coolant

Discussion about MX5s, Roadsters & Miatas, not directly fitting into one of the categories below. Please keep it on topic.

Moderators: LilRay.Sun, Furai, Growler, zorruno, jif

Post Reply
poison
Keep calm, Forum Moderator here.
Keep calm, Forum Moderator here.
Posts: 530
Joined: Sun Jun 11, 2006 7:47 pm
Location: JAFA Land

Maintenance - Check those hoses and replace the coolant

Post by poison » Thu Aug 28, 2008 11:56 am

While fitting a new alloy radiator (From MX5Mania in Aussie – full install guide soon to follow) I thought it’s a good time to put on a new lower hose, so I cut the old one off, then found I can only get genuine parts :cry: … but all is good, it turns out some genuine parts are pretty well priced only $22. And it was a good time to do the thermostat, a triton one was $29 and the genuine $39.00 being a critical component I have paid the $10 more for the genuine, if for no other reason I know the genuine one fails OPEN.

Also it’s a timely reminder perhaps to replace your thermostat and check your hoses now and again too. A failed or poorly functioning thermostat causes poor temperature control which in turn will cause poor running, poor economy, and potentially engine damage. As I once discovered the MX5 does not have an over temp warning light!!!! When a hose does fail you may not even know, who spends all day looking at the temperature gauge. At speed a hose can come off and you’ll lose most of the water in under a minute, and you may not even know.

SIMPLE - HOW TO CHECK YOUR HOSES.

This should be done at least once a year. And it’s also a good idea to replace your anti-freeze/anti-corrosion coolant fluid now and again too, and the corrosion inhibitor fails after a few years. Hose failure is a pain and can result in engine damage. There is no 100% test but a pretty good test is look and feel. The engine must not be hot, there is a serious risk of burns if a hose should burst.

The most likely hoses to fail are the ones directly connected to the radiator. There is one at the top and one at the bottom, they are about 50mm/2” diameter. So have a good look at them with a torch, do they look swollen (they should be about the same diameter all the way, sometimes they swell up next to where they join the radiator or engine. Do they have any cracks? If swollen or cracked, replace them or get them checked professionally.

Next give them a friendly squeeze. They should feel soft and flexible, if there is any cracking or crunching feeling they are well on the way to failure. Get them replaced immediately. The top hose is an easy DIY to replace, but the bottom one on the NA is a two piece and takes about an hour at home and is really really awkward . You need to get under the car too. The NB has a single piece lower hose and is easier but still tricky and frustrating, there is a plastic clip that will drive anyone crazy :evil: .

The other two must check hoses are the heater hoses, these are the two black hoses on the passenger side, going into the heater through the firewall (this is the car body steel panel behind the engine). The same check applies, look and feel. These are reasonably easy to replace at home, maybe an hour.

For some reason the other smaller hoses are much less likely to fail but still worth a check if you are at it.

TIP, old hoses can be hard to remove, cut the hose in half (after draining the radiator, with engine cold) so you have a nice long piece to hold onto and twist them to break them free, if they wont move you can cut along them, but be careful not to cut yourself (surprisingly easy to do in an awkward location) and also try not to damage the soft, alloy or plastic hose fitting underneath. Be careful with removing hoses from the radiator as the radiator tanks are plastic, do not bend them sideways to get them off, just twist or cut carefully, old radiator tanks can be quite brittle and can crack. The it will be many more $$$$.

Hope this helps and maybe saves someone being stuck in the middle of nowhere on a rainy night.
:twisted: Gazda in the white HOT Mazda :twisted:

dynofiend
Need, more, 5-ing, time....
Need, more, 5-ing, time....
Posts: 159
Joined: Sat Jun 21, 2008 6:26 pm

Post by dynofiend » Fri Aug 29, 2008 9:30 pm

To remove old hoses easily without cutting them, I usually just use a long screw driver to push the hose end away from the joint by a couple of mm. This breaks the seal and the hose will just pull off relatively easily after that.

poison
Keep calm, Forum Moderator here.
Keep calm, Forum Moderator here.
Posts: 530
Joined: Sun Jun 11, 2006 7:47 pm
Location: JAFA Land

Maintenance - Check those hoses and replace the coolant

Post by poison » Thu Sep 04, 2008 9:56 am

FYI, check the availability of those hoses before you cut them off (especially on the NB), Mazda had o get one in from Japan for me. Originally told me it would be 3 weeks… whattttttt!!!! But fortunately it came in after one week. Still a bit poor for a common part.
:twisted: Gazda in the white HOT Mazda :twisted:

Greenracer5
Keep calm, Forum Moderator here.
Keep calm, Forum Moderator here.
Posts: 47
Joined: Thu May 04, 2006 7:57 pm
Location: Auckland

Post by Greenracer5 » Wed Sep 17, 2008 1:25 pm

Hey,
have you ever thought about putting your talents as a DIY mechanic to good use by writing an article for the club magazine?
:D
Take it out and play with it.

http://miata.cardomain.com/id/britracinggreen

poison
Keep calm, Forum Moderator here.
Keep calm, Forum Moderator here.
Posts: 530
Joined: Sun Jun 11, 2006 7:47 pm
Location: JAFA Land

Maintenance - Check those hoses and replace the coolant

Post by poison » Wed Sep 17, 2008 2:20 pm

Good Idea I forget that a lot of club members don’t use the forum and many forum members perhaps don’t belong to the club. On that point I would recommend membership of the X5 club as the magazine is very good and many people seem to enjoy the club events.

I did some articles a couple of years back (Lumbar support, headrest speaker upgrades and CAI.. I think) , I’ll email them and offer the use of my postings, if they so wish. I am about to do one on installing an aftermarket alloy radiator too.
:twisted: Gazda in the white HOT Mazda :twisted:

Greenracer5
Keep calm, Forum Moderator here.
Keep calm, Forum Moderator here.
Posts: 47
Joined: Thu May 04, 2006 7:57 pm
Location: Auckland

Post by Greenracer5 » Wed Sep 17, 2008 2:38 pm

Excellent!
Just send stuff to topdown@mx5club.org.nz
It's great that folk like yourself who are technically minded have a place where they can share their experience. I realise the magazine isn't as direct or immediate as the the forum, but it still gives others a chance to see what's available and how to access it.

Cheers

G
Take it out and play with it.

http://miata.cardomain.com/id/britracinggreen

madandy
Tentative sideways sliding....
Tentative sideways sliding....
Posts: 39
Joined: Sat Aug 30, 2008 5:51 pm
Location: Toe ronga

Post by madandy » Wed Sep 17, 2008 5:26 pm

Just completed a hose & coolant change on my Na.. Full hose kit was in stock, ex Auckland, overnight delivery. Def a good idea to phone in advance to confirm availability.

Post Reply

Return to “MX5 Discussion”

Who is online

Users browsing this forum: No registered users and 20 guests