I just bought a 1978 mini from a user on this website. And when i get the car i was hoping to replace all the fluids in the car.
My question is what brake/engine/coolant Fluid should i get?
I have heard that you need to get the right mix of engine oil or it can be harmful.

I would like some recommendations for the best fluids and where to get them.
I would also like to change the oil filter so any recommendations for that would be great too
Thanks

Brake fluid: any known brand. They are all DOT 4(Dept of Transport - USA standard). DOT 5 is the latest upgrade and becoming available. Either will do. Worth checking front and rear wheel cylinders for leaks onto the brake linings before bleeding new fluid through system. New wheel cylinders may be needed from a local mini specialist.
Engine oil: There are many options I use Penrite HPR30 which is a 10-60 viscosity to suit older pushrod motors. I have found it also helps with gear changes in the gearbox in my minis. There are other brands and people have their own preferences which work for them, but oils for modern twincam motors tend to be too thin for older engine designs like minis sharing the oil with the gearbox. Oil filters will be a standard spin-on filter in many different brands. Change filters every time you change oil.
Radiator: Worth running the car with a radiator flush to know you have a clean system. Then use any coolant additive that is a corrosion inhibitor. Anti-freeze/anti-boil additives had a reputation for damaging head gaskets once but I don't know whether that is still the case. Originally (1960s) minis only used plain water in their radiators as there are few alloy parts to electrolytically corrode.

I can recommend GW XP 20/50 motor oil, costs around $17 for 4 litres from the usual outlets, and sometimes under 10 bucks when on special, excellent oil pressure when hot, and is recommended by mini racing guru GR here on The Ausmini forum, and is Australian made (look up their website). Most brands of oils will be ok (and are a lot dearer), but I reckon there is no need to spend any more than this. Oil filter should be replaced at each oil change are available at the usual outlets as well, but do yourself a favour, get to know the mini outlets around Melbourne and purchase from there. They are a wealth of information and all are very helpful people.

Dot 4 brake fluid of any major brand is the one to get, it has a higher boiling point than Dot 3 so I'm guessing if you give the brakes a hiding, they won't fade as quick.

For radiator coolant, most brands are ok, but suggest you get the 4 year type. Don't buy the cheap stuff.

I'd stay away from DOT 5, it's a silicone based fluid unlike DOT 3/4/5.1 which are polyethylene glycol, so if you want to run DOT 5 you need to flush it completely, they are incompatible. Either DOT 3 or 4 will be fine, but DOT 4 has a higher boiling point.

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You raise an interesting point: is there a DOT5.1 that is compatible with most generally available brake fluids and a DOT5 which is a silicone base?
I have not seen a DOT 5 fluid so are they clearly marked as silicone based?

Dot 4 wil remove your paint. The dot5 wont... One advantage But cant mix them

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DOT 5.1 is the evolution of DOT 4, same basic chemical composition and so is compatible with 3 and 4. DOT 5 is incompatible. DOT 5 doesnt ruin paint and it's not hygroscopic (Doesn't absorb water).

Not sure on the availability, I haven't ever really looked!

You can buy dot 5 at Harley Davidson dealers ,I have been using it for years , very good if car sits around not being used much particularly in a humid climate, hydraulic system not rusting from the inside and does not damage paintwork is enough for me to use it.
Cheers,
John.

If i was to go for the DOT 5 what would be envolved in cleaning the brake lines so that it would mix with what ever is in there at the moment

Should really fit all new seals or cylinders, and flush the lines out with metho if going for dot 5 silicone fluid.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

For someone fitting all new braking components (metal lines and rubber hoses, slave cylinders, master cylinders, servo, etc.) it seems from this discussion that DOT5 is the way to go, yeah?

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ex-NSW Police 1970 MK II Cooper S
VMCI #43

The big advantage that the DOT5 has besides not being hydroscopic, and partly because of that, is that it has a much higher thermal range. In other words your brakes can get hotter before the fluid boils and gives you heart stopping, but not car stopping, brake fade. But the DOT5.1 seems to have caught up on that side of things.

Another advantage over other forms of brake fluid is that DOT5 silicone has a more stable viscosity index over a wider temperature range. This is good for drivers who want to have a consistent pedal feel over all brake temperatures likely to be experienced.

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the world is a book, and those who do not travel read only a page
66 Mini Minor sponsored by http://www.lifeonthehedge.com.au/ The Dog Harness Specialists
It was a pleasure ausmini. I'll miss all you misfits and reprobates

I have assembled all the brake components on my car using PBR brake grease although I haven't put any fluid through the system yet. If I now use DOT 5 silicone fluid in the system, will there be a problem with the PBR brake grease already on seals, etc?

I guess i will post here before i make a new thread.
The time has come for a first fill up of petrol what type should i go for and do i need to add anything to it?
Thanks for the help

I have not used it.. but friends who have are not that keen. DOT 5 fluid does not absorb water but is prone to retaining air... You need to be very careful when filling the system (and bleeding) to ensure you don't introduce (very small) bubbles. Most people i have spoken to complain about a spongy pedal... that they aren't able to get rid of.

My observation is that its good for cars that sit around and are unused for protracted periods. It does protect the system from the consequences of sitting around ...and doesn't eat paint... The down side seems to be a lesser level of braking performance......

Yer pays yer money and takes yer chances...

Cheers, Ian