Hose replacement

[mk1divemaster]

Hi all , coming back from a mx5 run had a sudden coolant loss when I parked up at home , checked where the problem was , and I found the ISC vale to inlet manifold hose had split , belching out coolant all over the alternator etc! So I got to work. While all coolant was drained I decided to replace the heater hoses at back of engine too :-

1 Drain the system of coolant , put a container that can hold upto 6 ltr of liquid under the drain plug then undo plug and let the coolant drain , open filler cap and it will come out quicker.

Drain plug

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2 locate broken hose/ hoses and take out ( make sure you have replacements !!) the ISC valve to Inlet manifold one was very tricky to release, as it had the original spring clips on it so very hard to get grips in to squeeze together. I removed the two hoses that were around it to give me some purchase.it takes some patience .

ISC valve hose

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3 I then took off the heater hoses that lead into the firewall / bulkhead , the first hose was a doddle
release spring clips then I carefully cut the ends with a blade to help pull the hose off as it was fixed tight after years of use. The second is a bit of a bugger as it goes behind the engine underneath the coil pack , I persevered and took it out with some long nose pliers , but i think it will be easier if you took coil pack out of the way ( three bolts).

Before

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4 I then cleaned the stubs and put a little washing liquid on ends to aid sliding new hoses on.

Stubbs clean

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5 I did the same to the ISC / Manifold Stubbs too.

6 I put the new heater hoses on and fastened the clips .

New hoses in place

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7 then attached the new ISC hose with new jubilee clips ,instead of the spring clips for easier removal next time.

New hose and clips

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8 I then flushed the radiator through with a garden hose for a few mins to get rid of any sediment etc (I ran it until the exiting water ran clean) then replaced the drain plug.

A quick flush through

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9 I took off the plastic expansion tank to give it a clean while I was flushing rad. Three bolts .

9 then I added fresh coolant 2 ltr of anti freeze. With 4 ltr of deionised water , you probably won't get it all in straight away until engine is warm , so just fill to neck of rad ,leave rad cap off then start engine and let her idle until the top hose gets warm and the thermostat opens up.the coolant will drop then so you can add the remaining fresh coolant. Add some of the coolant to the expansion tank , up to in between the low and full markers .Put rad cap back on have a wipe around , jobs a good en !


10 give her a run and check for leaks

Guilty ISC hose

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[nedski]

Well done great how to post .

[flea]

Great post. Well done

[DavesBRG5]

Job well done

[mk1divemaster]

Cheers all

[Mazda Mender]

Just a tip....
It will be far easier with the coil pack removed and if the hoses are dead, then be careful but just cut the rubber hoses clean off from the metal bulk head and engine side ends, leaveing a stubby hose and clip still attached which you will find that getting to the sring clips off and to a lot easier as you can bring it straight off and out , then just cut along the length of the stubby left over pipe to just peel in half and off, more so on the bulk head heater matrix stubs as they are a vey fine brass or copper pipe and can be crashed very easy, and if you do get them out of shape they will never make a seal and will need to be removed and swapped with new....big job.
Don't forget tp put the hose clips onto the new pipes before fitting

Great write up buddy
M-m

[mk1divemaster]

Cheers bud

[cjgreaves41]

Chaps.

Just doing the coolant change on mine. Ive bought Comma Super cold Master. The last time the coolant was changed it was done at a garage... The mixture that I have drained out appears pink, as I didnt chnage it I've no idea what it is.

Is there a problem with mixing coolants? If so whats the best way to flush the system completely? Prior to putting the new stuff in?

Cheers

[Lazza]

No problem mixing any coolants that are compatible with the MX5 cooling system.

[Mazda Mender]

Years ago there was as they were two different chemicals which did not like each other, just make sure you do the 50/50 mix correct, as to much is just as bad as not enough.
The cooling system holds 4 1/2 Ltrs so you need to add 2 1/4 concerntrated and then water, run her and bleed off for air pockets.

But remember you have 2 year and 5 year antifreeze now, the colour stuff is a load of crap these days to.
M-m