Moodles2

I don't know R34's well, but all Skylines have a thermofan infront of the aircon condensor (looks like a radiator). This will switch on automatically when either the aircon is on, or the coolant temperature reaches 95C+ (approx).

I'm in the same boat, HICAS hasn't given me any issues so I've left it as is.

Silicone vacuum hoses are very slippery, if it slips off the FPR you will lunch your engine

You use the brakes more than the clutch, brake fluid can get up to and perhaps beyond 250C under heavy conditions on the road (easily 300+ at the track) as it absorbs heat from the calipers, discs, and pads whereas clutch fluid just acts actuates the engagement of the clutch. So that's why clutch fluid stays the same color, whereas brake fluid will blacken over time.

Mines a standard '94 R32 GTR and I don't have brembos, as above only V-Spec & V-Spec II had brembos (and possibly N1 as well I'm not 100%)

Whatever is cheap, it can all be mixed as each DOT specification is chemically compatible. As long as you don't get DOT5 which is silicone based, DOT4 or DOT5.1 is what you want and both superior to DOT3 (I doubt you could find DOT3 anyway) If you are chewing through brake fluid, then you might have a leak somewhere in the brake lines, pinhole leak in a rubber hose for example.

Definitely change the fuel filter asap, it might be blocked with rubber debris from the blown hose.

You can turn the recirculation button on while the aircon/heater is turned off, it will stop passive air from coming from the vents.

By oil cooler, are you referring to the factory oil/water heat exchanger?

The sight glass is there, what do you see when you look in?

Pretty sure the apexi solenoid is just a standard mac valve, Vipec should control it no probs.

Soot and carbon buildup are a byproduct of the combustion process, if the oil is still honey colored after 5000km then there is 2 possibilities I can think of. The engine is extremely clean by engine health (good compression etc) and the tune itself (not overly rich etc) or the engine oil by design has minimal detergents for cleaning

The oil temp sensor (near the oil filter) might be disconnected, or even worse, faulty. Need to do some probing with the multimeter to rule out the oil temp sensor first before looking at the gauges.

Might be a problem with the G-sensors (under the centre console), usually they only play up if you've physically messed with them.

R12, but that gas isn't legal to use anymore.