Flushing the MG Midget’s cooling system

In this episode we drain the old coolant, flush and backflush the system a few times, as well as adding a chemical flush, before filling the system back up with new coolant.
We also change the thermostat and repair / refresh some of the components along the way.
Thanks for watching and please give us like, if indeed to you did, and leave any comments you may have to help us improve the channel.

[@schaumyb7445]

Hi, Thanks for making this video. It was good to see how the oil cooler sits in front of the radiator because I have now just re-installed an oil cooler in my 71 Aussie assembled Midget and there was not any existing brackets or holes to refer to. The kit did not have a thermostat, and I probably don''t need one for just cruising around on the weekend. The new kit is metric of course, and the rest of the car SAE, but now I just have more tools!

[@JerryMotorsport]

Thanks for watching and thanks for your comment. There is more of the oil cooler in my video "Completing the changing of the MG Midget's oils": kzbin.info/www/bejne/mZrMZGhoh9eIfK8 . Depending on your climate and if you are just cruising around you might want to consider fitting a themostat so you don't 'over-cool' the oil. Without one it might never get 'up to temperature'. Although if you are racing you probably would warrant constant cooling. All the best...

[@bisonuberti]

You make it seem all easy. two thumbs up. Cheers.

[@JerryMotorsport]

Thank you so much 😊

[@windmill1965]

I'm surprised to see that you let the chemical flush simply drain all over your driveway. Besides environmental considerations, didn't it cause stains or smells on your driveway?

[@JerryMotorsport]

Thanks for commenting; it's a good point and something I probably should have said in the video. The power of editing! I used a washing up bowl under the car for the initial and chemical drains; you can't see it in the shots looking into the engine bay (and a some did spill out as the water went everywhere) and I didn't film it from below. The shots showing it going on the driveway were from a 'staged draining' I did later to get some water falling footage and I edited it in to earlier parts to make it more interesting; so yes I admit it did look like it went all over the drive and the staged water wasn't completely clear. The washing up bowl only just fitted between the chassis and the ground so took it out for those staged shots (B-roll). No staining on the drive and no smell either; seem to recal the flush was biodegradeable as most things have to be now. Water was never as dirty as I had anticipated / hoped; but the flush did improve the heat output from the heater.

[@windmill1965]

@@JerryMotorsport Thank you for your extensive reply. The last couple of days I have been going through the same process: draining the cooling water from my MGB, flushing it several times with water, until it was less murky and had less of a rust-colour. Then I filled with antifreeze as it also has some rust-preventing additive. I'm hoping that this is a better choice than regular water.

[@JerryMotorsport]

@@windmill1965 Sorry I missed your reply. I would never advocate just plain water in the coolant system (exept in an emergency type scenario). Even if there was no danger of the coolant freezing, the corrosion inhibiting properties of the additive is surely a must in any engine. Hope the work on the MGB went well.

[@windmill1965]

@@JerryMotorsport Yes, coolant replaced. Up to the next job, as there is always something left to do.

[@petermitchell8431]

Yeah - that's not at all a good thing to do.

[@lindametcalfe728]

Great video

[@JerryMotorsport]

Glad you enjoyed it

[@046sillogue]

Good video , step by step, don't think you need the background music,

[@JerryMotorsport]

046meath thanks for comment. I added the music as it felt a bit ‘dry’ without it. Onwards and upwards 😀

[@bisonuberti]

Jerry... are you flushing the heater-core? If so, where is the out flow and is the heater valve opened?

[@JerryMotorsport]

Hi, yes I flushed the heater core as well as the main cooling system. The isolation valve is curently stuck in the open position so when I added the flushing chemical it would have gone around the heater matrix too. At 7:51 you can see I've disconnected the hose from the heater isolation valve to fush through fresh water to make sure I got as much cleared as possible from the heater. Ideally I would have used the other hose (upper from the core) and flushed in the opposite direction to normal flow; this was just easier to remove the hose from the valve.

[@rangersasc]

Jerry you have a nice Rocker Cover on yours, i want to add one on mine but i heard with the 1275 once you add an Alloy Rocker cover on you need a vented oil filter cap because usually they do not have provisions for venting, no vent would allow crankcase pressure to build and would blow oil past even new seals ?

[@JerryMotorsport]

Hi Raymond, thanks for commenting. I've not heard that before. Personally I don't see how the material would have an effect on the requirement for a vent; it's still a cover. Our filler cap is 'loose fit' so guess that allows some venting. I'll take a look at the pressed steel cover I've got in the garage and see if there are any diffferences or vents that have been 'omitted' in the alloy cover. All the best.

[@rangersasc]

@@JerryMotorsport ok cheers mate. i do want to get a new one i just dont want to mess anything up along the way, thanks again.

[@montysonful]

Not clear what, how you connected the garden hose.

[@JerryMotorsport]

Pretty sure I just shoved it in one of the radiator hoses. Thanks for watching

[@boosimon]

Another good one Jerry. Glad to hear you mention replacing that thermostat housing :-). I got my replacement via ashleyhintonmgparts2002 on eBay a few years ago. And not at all surprised the steel lower pipe had failed as I'm sure they all do regularly. Mine was far worse, unfortunately, so replacement needed. Curious whether you got the rough running solved, and related to over-temperature?

[@JerryMotorsport]

Thanks Simon. Musn't forget to replace that housing. Car runs a little better after the flush but I need to use the car in a bit more anger to see if I still have the rough running issues. A healpful viewer has sent me some suggestions to try around the fuel pipe to the carb.

[@rangersasc]

Jerry on my 72 i noticed my engine coolant temp switch is broken and has no wire on it, do you happen to know where the wire needs to go that come off of it should i get a new one ? cheers my MG has some issues

[@JerryMotorsport]

Raymond, can you send me a picture (email or Instagram) of what you are referring to please? I think you might be talking about the temperature sender, but 'switch' has confused me.

[@rangersasc]

@@JerryMotorsport Yes sorry it is the Temp sender

[@leeshaw8923]

Could I ask what make gasket sealant you used please? Thanks.

[@JerryMotorsport]

Thanks for watching and commenting. I used Granville Instant Gasket - never used it before just what my local Halfords had. Have used Blue Hylomar in the past.

[@leeshaw8923]

@@JerryMotorsport Thanks Jerry.

[@TahoeRealm]

Can you explain the backflush process? Thank you

[@JerryMotorsport]

All a backflush really is doing is removing any deposits from the cooling system. As the system is pumped in one direction the flushing water is ofen pushed round in the opposite direction (but not essential) hence the name. I flushed clean water through in any direction I could attach a hose to the system. With deposits and any restriction buildups from the system removed, potentially enhanced by a chemical flushing agent, the system can operate more effectively in keeping the engine temperatures under control through better flow through cooling areas (radiator) and better heat absorbsion in the engine water galleries. Refilling with a corrosion inhibitor after flushing helps prevent a sludge build up accumulating again and often acts as an anti-freeze too. Hope that answers your query.

[@TahoeRealm]

@@JerryMotorsport I thought that is what you meant but just wanted to be sure. Thanks for the thorough explanation!

[@joecritch143]

Well i don’t think letting the coolant out onto the ground is a responsible thing to do. And you should flush with deionized or distilled water.

[@JerryMotorsport]

Hi Joe, Thanks for watching and commenting; it's a good point and something that was picked up six months ago; I probably should have said in the video about collecting the coolant. The power of editing! I used a washing up bowl under the car for the initial and chemical drains; you can't see it in the shots looking into the engine bay and I didn't film it from below. The shots showing it going on the driveway were from a 'staged draining' I did later to get some water falling footage and I edited it in to earlier parts to make it more interesting; so yes I admit it did look like it went all over the drive. The washing up bowl only just fitted between the chassis and the ground so took it out for those staged shots (B-roll). I suppose I could have flushed with deionized or distilled water but i would have had no pressure; plus the coolant is mixed with tap water anyway so didn't see it as a huge issue.

[@stevewoodbridge5648]

Why on earth do you feel you have to put annoying music on at the same time as you are talking. It makes no sense and is just distracting.

[@JerryMotorsport]

Noted, thanks for watching Steve