8 replies to this topic

[john2502]

Hi All

 

Just wanting to double check process before I do this as seen some small variation in previous discussion. Coolant change on my 2000 MPI needs doing.

 

1. Car cold, cabin heater set to hot, remove bottom coolant house (no drain plug on MPI) and expansion tank cap, let fluid drain out (guessing this will be messy!)

2. Run hose in expansion tank at low pressure (so as to not damage heater) through until runs clear out bottom hose

3. Re-fit bottom hose, fill up with 50/50 coolant mix (red in my late mini's case) up to max line

4. Run car up to temp with expansion cap off to bleed system,

5. Dispose of coolant at local waste recycling centre (used to be called the tip!)

6. Check level and top up if needed.

 

My question is, is step 4 needed? I've done classics before where it is but have never bothered on modern stuff so wanted to double check. Have i missed anything?

 

Also, not sure whether to run flush through for a bit first, would this stuff do?

 

https://www.eurocarp...hxoC8Z4QAvD_BwE

 

Thanks for any advice.

 

John

[Steve220]

Hi John,

If you do no.2, its just going to come out the bottom hose and not flush. Personally I'd remove the hose join for the heater matrix (comes out the bulkhead on the far right, right hand hose), then push the cold water back into the heater matrix with the bottom hose off. That way it should get it all. Usually I remove the radiator to back flush it, but appreciate that'd a ton of work.

After, I'd fill it with fresh water, drop a dishwasher tablet in the expansion tank, run it for around 50 miles then drop the fluid again. Refill with 50/50 coolant to water mix. Don't fill to the max line! Fill to around half an inch below it.

Edited by Steve220, Yesterday, 01:58 PM.

[NLinPEN]

An alternative to undoing the lower radiator hose (difficult to reach) is to remove the fan switch from the radiator and let the coolant drain from there. If you choose this method though you need to ensure that you have some new seals before you install the switch.

Whatever method you choose it is indeed a bit messy as you can't properly control where the coolant flows to. I use a small size inflatable baby pool, place it under the car and inflate it until it touches the bottom of the car. Then let the coolant drain into it, partially deflate it and pull it out. This worked nicely for me.

[Blumeanie]

I use a disposable Al baking pan to catch thr coolant from the lower hose. It works well and not mutch is splashed outside of it.
I find the spring clamp at that bottom radiator hose location to be easy to reach & manage.

I agree on filling with water only (I use distilled water) and running the car for a bit. (I've never used any cleaning agents... - its interesting.)

Then empty again and fill with coolant mix also with distilled water.

We don't get freezing weather here, so I only use some 30-35% antifreeze in my mix. This provides better cooling properties.

Fill to just below the max and check and adjust level after a few miles as air will be cleared from tge syste.

Edited by Blumeanie, Today, 05:36 AM.

[john2502]

An alternative to undoing the lower radiator hose (difficult to reach) is to remove the fan switch from the radiator and let the coolant drain from there. If you choose this method though you need to ensure that you have some new seals before you install the switch.

Whatever method you choose it is indeed a bit messy as you can't properly control where the coolant flows to. I use a small size inflatable baby pool, place it under the car and inflate it until it touches the bottom of the car. Then let the coolant drain into it, partially deflate it and pull it out. This worked nicely for me.

 

I think I've read on the MPIs this is in the thermostat housing, I must admit I haven't looked yet.

 

Baby pool idea is a great one! Never thought of that and I have 3 young kids so we already have one. Guess i should probably wash it before they use it again! haha

[john2502]

I use a disposable Al baking pan to catch thr coolant from the lower hose. It works well and not mutch is splashed outside of it.
I find the spring clamp at that bottom radiator hose location to be easy to reach & manage.

I agree on filling with water only (I use distilled water) and running the car for a bit. (I've never used any cleaning agents... - its interesting.)

Then empty again and fill with coolant mix also with distilled water.

We don't get freezing weather here, so I only use some 30-35% antifreeze in my mix. This provides better cooling properties.

Fill to just below the max and check and adjust level after a few miles as air will be cleared from tge syste.

That's a good idea too yeah, will keep that in mind.

 

I guess being in California yeah you don't have to be so concerned about the freezing element and more the cooling side of things yeah!

 

I usually air slightly on the side of water so more a 40/60 mix roughly and has usually been ok.

 

Thanks

[NLinPEN]

Baby pool idea is a great one! Never thought of that and I have 3 young kids so we already have one. Guess i should probably wash it before they use it again! haha

 

Yeah, you won't be able to reuse that baby pool for its original purpose after you have used it for catching dirty coolant.

[Steve220]

An alternative to undoing the lower radiator hose (difficult to reach) is to remove the fan switch from the radiator and let the coolant drain from there. If you choose this method though you need to ensure that you have some new seals before you install the switch.
Whatever method you choose it is indeed a bit messy as you can't properly control where the coolant flows to. I use a small size inflatable baby pool, place it under the car and inflate it until it touches the bottom of the car. Then let the coolant drain into it, partially deflate it and pull it out. This worked nicely for me.

There's no sensor on the MPi radiator.

[Steve220]

I use a disposable Al baking pan to catch thr coolant from the lower hose. It works well and not mutch is splashed outside of it.
I find the spring clamp at that bottom radiator hose location to be easy to reach & manage.

I agree on filling with water only (I use distilled water) and running the car for a bit. (I've never used any cleaning agents... - its interesting.)

Then empty again and fill with coolant mix also with distilled water.

We don't get freezing weather here, so I only use some 30-35% antifreeze in my mix. This provides better cooling properties.

Fill to just below the max and check and adjust level after a few miles as air will be cleared from tge syste.

That's a good idea too yeah, will keep that in mind.

I guess being in California yeah you don't have to be so concerned about the freezing element and more the cooling side of things yeah!

I usually air slightly on the side of water so more a 40/60 mix roughly and has usually been ok.

Thanks

The 50/50 mix is to protect the ferous pig iron the block is made of. Otherwise it will just rust heavily again.