Heater Matrix Hoses

[J-Tuner]

Afternoon chaps

Sods law isnt it. Just the other weekend finished my rocker cover gasket and CAS O-Ring replacement (a pefect time to sort this out) and shortly after notice a tiny coolant leak from the heater hose nearest the engine. Its actually leaking down the bulkhead where the hose attaches the copper stumps so i assume either the hose has perished on the underside or the spring clips no good. Either way ordered some new kevlar reinforced hoses and jubilee clips from autolink.

My question is : Can i get away with fitting these without touching the coil pack/rocker cover and CAS Sensor? And is it worth draining the whole system down or can i just cut the hoses off and just lose a litre or so on the floor before it finds a level and stops ? Just trying to make this as easy and quick as possible.

Cheers

Steve

Edited by J-Tuner on Thursday 23 June 16:20

[BonzoG]

I had to take the coil pack off - but I have large hands and hadn't heard of hose clip pliers!

Whatever coolant was in that part of the system had already made a bid for freedom, but draining the radiator isn't hard - just unscrew the drain plug on the bottom. There's a handy access panel in the undertray so you don't have to take that off. If you're particularly dexterous you won't even have to jack the car up.

Edited by BonzoG on Thursday 23 June 17:32

[J-Tuner]

Yeah i know draining isnt a huge amount of work, just trying to limit the time i am working on it - mainly so i don't get grief off the missus for being out on the drive all day haha..

So its possible to swap them over without disturbing my newly sealed rocker cover. I can handle coilpack removal if absolutely required - sweet !

[BonzoG]

Part of me thinks it'd probably be best to drain and refill anyways, just to avoid any pesky airlocks, but thinking about it, the system is under pressure and if you refill then run it with the cap off until it's free of bubbles, then it should be fine just as if you'd drained it completely? Not sure on that one!

[J-Tuner]

If i have gone that far though its not a massive hardship to get the car on a few bricks and run the engine and top up for a while. Not sure what these are like in terms of being prone to airlocks?. I know my old 200sx was a bit fickle and liked to be burped properly and not rushed

Does i need a specific coolant (red or blue?) or anything is fine ?

[BonzoG]

Any ethylene-glycol based low silicate coolant will be fine. I've seen red, blue, luminous orange, bright pink - all met the same spec. The pink stuff was great for checking the level in the header tank if the plastic is old and cloudy!

Edit: In other words don't go by colour, read the label!

Edited by BonzoG on Thursday 23 June 17:49

[J-Tuner]

Wise words my friend

I have bright orange in there at present (was only done recently when the Rad was swapped, and is great to check the level as you say. Will see what i can get my hands on.

Cheers

Steve

[MX7]

J-Tuner said:

My question is : Can i get away with fitting these without touching the coil pack/rocker cover and CAS Sensor?

I did it, eventually. I had to cut them off with a small, sharp (kitchen) paring knife, and then did away with those silly clips and put some jubilee clips on.

[HalfMoon]

I changed my heater hoses yesterday. Ended up having to remove the CAS to get the hose clip off but didn't need to move the coil pack. I didn't drain the system as I'd already lost coolant from the split hose - so only lost a tiny amount when removing the hose - and had no issues with airlocks.

[towelie]

yer has already been said just cut the hoses off, i would take the coil pack off aswell makes it alot easier.. I read somewhere that the mx5 isn't very prone to airlocks at all, i haven't had any problems and last summer i seemed to be doing ALOT of dropping coolant and putting new in, due to various problems in the cooling system arising and the odd auxiliary belt change.

[J-Tuner]

UPDATE : Ok 6pm saturday evening i decided i was going to put the new hoses on

I ordered kevlar reinforced items from Autolink and new jubileee clips. Very impressed with the fast delivery and the quality of the items. Cheapest i could find anywhere.

The job in total took me 2 hours - most of the time was spent on releasing the lower rad hose clip and then trying to yank the pipe off the rad. I didnt jack the car up, and my car is lowered so much so that the access flap wouldn't flip open

My observations that i hope help others trying this for the first time :

1)As mentioned before - no need to jack up the car. Was performed on level ground.

2)For low cars i recommend a x-large paint roller tray to collect the coolant without spilling. I guesstimate around 3/3.5 litres was chucked out. Overflow reservoir was left full.

3)I used a modelling scalpel to slice though the hoses as close as possible to the stubs. A sharp blade makes the jobs very easy and safer. After i removed the spring clips and then sliced lightly vertically down the pipe to weaken it then got a set of pilers and twisted whats left of the hose off.

4)Old hoses are pretty much baked on - dont even attempt to pull them off without cutting them.

5)I managed to removed the hoses without the removal of the coil pack or CAS Sensor. However i did remove the elbow section of the standard air filter pipework. 2 bolts, 2 seconds. Makes a big difference and was easier than removing the coilpack.

6)I was able to use a jubiliee clip on the lower part of the hose that is hidden up the back of the bulkhead. initially it looks like its impossible without removal of the CAS Sensor and coilpack, but it is indeed possible to tighten this one up by slipping down the bulkhead a small ratchet and a 7mm socket and taking your time to tighten it up square on the hose.

7)Filling up the rad and 'burping' the system whilst the car was on level ground was a piece of cake. Just put the heater on full and let the car idle whilst topping up. No issues to report unlike some cars with airlocks being a pain etc. Did need a tiny top up the next morniing once the system had cooled - but otherwise all good. For reference i used Halfords professional pre-mixed 50/50 coolant. 5 litre bottle but only used 3/3.5 litres i think. I recommend this one since its luminous orange and makes it very easy to spot any leaks.

Thats it really. Wasn't quite the nightmare i had envisaged and was really pleased with the fast swap over. The autolinks hoses were a perfect fit.

Hope that helps someone

Cheers

Steve

Edited by J-Tuner on Monday 27th June 12:13

[Richyvrlimited]

MX7 said:

I did it, eventually. I had to cut them off with a small, sharp (kitchen) paring knife, and then did away with those silly clips and put some jubilee clips on.

You may think they're silly, but they're superior to the jubilee clips you replaced them with.

Spring clips provide a constant amount of pressure to the hose. So when things swell and contract due to varying temperatures, as does the spring clip, maintaining the correct pressure.

With a jubilee you over-tighten hoses crushing the rubber and reducing it's lifespan, whilst simultaneously potentially cause a leak further down the line by not allowing for expansion/contraction.

[MX-5 Lazza]

Jubilee clips also tend to corrode unless you've splashed out on some nice expensive stainless ones.

[J-Tuner]

Not wishing to start an arguement on that topic but i've never had issues with jubilee clips shortening hoses lifespan as long as you are sensible with the tightening. Corrosion on non-stainless clips is true however i've still never had issues getting one off or reusing it. I used clips like that on my intercooler pipework on my old car which were really exposed at the front of the car and were fine after years of exposure.

I'd sooner use those personally as they can be tighened later on if required. Upon investigation of my leaking hose, i couldn't see any splits or perishing so its looking likely that the spring clip wasnt applying enough pressure. A jubilee clip would have made an adjustment easy. This is something i've seen before on other cars.

Each to their own though eh

[MX7]

Richyvrlimited said:

With a jubilee you over-tighten hoses

You've seen me tighten up a jubilee clip?

MX-5 Lazza said:

Jubilee clips also tend to corrode unless you've splashed out on some nice expensive stainless ones.

When they get very old, but I tend to always replace them.

[Richyvrlimited]

With a jubilee at some point they'll always be too tight, that's the point. You tighten the clip then the car warms up, the pipework expands and then it's all too tight.