Is changing fluids a mandatory maintenance procedure?

[spyghost]

Hi,

I was reading the casa pms sched/procedures. Napansin ko na merong dong drain and replace this fluid, and that fluid for this certain mileage.

Question ko e, is it really a requirement to change the fluids such as coolant, power steering, etc?

Ano benefit nito?

[v6dreamer]

Its not mandatory, its nescessary. Just like yourself, its not require to have a bath no matter how dirty you are but, its nescessary for the sake. So with your vehicle needs also a fresh fluid or coolant.

[Eismann]

It's mandatory to keep your car running in tip top shape.....at least every 80T km change transmission, differential, power steering, oils and brake fluid.

[mbeige]

Let's take oil as an example. Dino or mineral oil breaks down, synthetic oil does too but much less than mineral oil. When you have old oil in your car's engine, it cannot protect the internal parts as well as it should, like with fresh oil. An old oil filter will clog up eventually, so that obviously needs to be replaced. In a specific example of diesel oils, that have soot protection, the oil will degrade over time and will absorb the soot the engine produces. These particles blacken the oil, and act as microscopic abrasives, so it's like sandpaper in your engine. The longer you go without an oil change, the rougher the sand becomes, so to speak. And the protection capabilities also diminish rapidly.

The same goes with coolant, transmission fluid, power steering fluid, differential oil, ball joints (although for those you just replace the whole ball joint, but some cars had grease nipples back in the day, and had to be periodically lubricated as well), etc.

Think of it this way, would you like to drink rotten (insert liquid like milk, juice, etc)? I'm sure if your car could answer that for you it would have the exact same answer.

[Type 100]

Oil: Gets dirty; breaks down into sludge under engine heat.
Coolant: Gets dirty and less efficient.
Brake fluid: ABSORBS WATER = becomes less resistant to fade because it boils at a lower temperature as it absorbs more water.
Fuel: Not really a major concern, but sediment from fuel stations can come into your tank and clog fuel lines or injectors.

Driving around without regular flushing and replacement of the fluids mentioned above (apart from fuel) is an accident waiting to happen.

[mbeige]

Actually, stale fuel also must be drained first, diesel especially. If the car has been sitting for so long, for example, you'll also need to open up the cylinders to check for rust if one of the valves was open before it sat for that long. Of course this is slightly off already but what I'm saying is fuel isn't an exception to the rule

You're right on the ones you've mentioned. To add, if brake fluid absorbs water, the brake lines rust away, so do the calipers and get seized.

[mazingerZ]

Tanong na lang din ako, bakit kung diesel nangingitim ang oil, kung gasoline engine tama ba na ang used oil parang nagiging scarlet ang kulay? Why ?

[mbeige]

Diesels produce soot, which is absorbed by the oil, to prevent it from damaging the engine. That's what makes it turn black.

Gasoline engines do not produce soot, but the wear and tear makes it brownish after a while. Same principle, it wears the oil out. Hence the need to go through an oil change as part of the maintenance.

[[archie]]

i do know thats its necessary to do this... but i have a question, when do we change the brake tranny ps oil? is there a specific rule on this?

is it done every "x" amount of kms or years? or which ever comes first?

thanks...

[mbeige]

Some manufacturers have recommended intervals for which to change certain fluids, filters, etc. For example, in my Haynes manual (the owner's manual doesn't have it), my car's recommended oil change interval is every 5,000 miles in normal operating conditions, but in severe conditions (stop and go traffic, driving in lots of dirt, going off road, etc) it's cut down to half every 2,500 miles instead.

Some owners have adopted their own ways of maintenance. A good estimate would be to do these once a year at the very least. Of course, more frequent changes need to be done for more critical components like the engine oil, but some oils like synthetic ones or multi-grade can hold on much longer than regular dino/mineral oil, as I mentioned earlier.

However, the "yearly" basis is for regular/normal drivers who usually travel 15,000 miles a year. My experience from reading around here is that if it's recommended to change every xxxx miles, just change miles to kilometers, for Philippine settings. For example, oil changes need to be done every 3,000-5,000 miles depending on usage, so just do it for the same range - 3,000-5,000 - but in kilometers instead. If the annual mileage is 15,000 miles here in the US, it's 15,000 kilometers at most back there. Me, I travel 11-12k miles a year here, so that's roughly 11-12k km there, "converted". Maybe it's just my observation though, but that's the pattern I've noticed.

[[archie]]

^^ hmm.. i think your talking about the engine oil sir. how bout the other oils.. like brake, tranny, power steering? how often do we change it?

is it also annually? ive heard na 80k or 8 years... which ever comes first. is this the basis?

[mbeige]

8 years for brake, transmission fluid, power steering fluid, etc? Wow, that's way too long. Like I said to be on the safe side have it done annually at the very least. Kahit brand new sasakyan, it helps to minimize wear and tear during its first few years. That's the key to longevity in cars.

Maybe it's already different for newer cars? Where did you hear about that?

Like I said some manufacturers recommend certain time intervals for which to change particular fluids. Some fluids will have similar time intervals but others can last longer, maybe like the transmission fluid. I wasn't particular to just the engine oil, but it really depends also on the conditions the cars are subjected to.

[[archie]]

that was what the mechanic told me when i had it serviced at 40k kms... i thought tama siya kasi back then i was relatively new to auto world... its not that necessary daw to change the brake tranny power steering oil often.

kaya ngayon im still guessing when to do it...
hmm ill have to check this out with the manuals... (though i think i lost it)

thanks for the reply sir, ill definitely take that into consideration.

[mbeige]

Well, it's not really necessary to do it, but periodically check them na rin. Given our driving conditions, mileage isn't really proportional to wear and tear. In fact, due to the traffic conditions it's more wear and tear than mileage (you don't travel a lot yet your car suffers extreme driving conditions).

Some power steering units from other cars have filters kasi, kaya I mentioned it na rin.

ATF should be bright red and should not smell burnt. Manual transmission fluid - not familiar - maybe you guys could chip in here.

Power steering fluid is usually clear, rather thick compared to ATF. Some P/S units use ATF (older cars). If in doubt, go with the recommended fluid type and proper specifications.

Brake fluid should be clear, somewhat viscous like power steering fluid. DOT 3 and DOT 4 can be mixed, but DOT 5 should never be mixed with DOT 3 or DOT 4. DOT 4 has a higher boiling point than DOT 3 and is usually recommended for higher performance vehicles. When checking the reservoir make sure you check all chambers. Some have more than one chamber, often these are overlooked. Hence, poor braking results.

Oil on gasoline cars should be a very light golden color, the clearer the fresher. On diesels it usually turns black but that depends from engine designs. Know which viscosity works for you, if your application requires mineral/dino oil or synthetic, etc.

Coolant mixture - highly recommended to go with manufacture recommended fluids to obtain the most protection. Replace yearly if possible, to prevent corrosion of cooling system components. pH test is done to verify condition of coolant mixture. Only fill up reservoir to maximum recommended level, to allow for residual coolant from the radiator (as a reserve space).

Differential oil - not regularly changed of course, but use correct specifications.

^...just off the top of my head...

[4JGtootsie]

Oxidation is the primary cause of darkening oil. In engine, powertrain, pumps, brake pistons/lines/housing where most components can rust because of oxidation the fluids obsorb this and during time it gets saturated. Not replacing fluids according to PMS will rapidly wear this components. We also have to remember that it is inherent to oils to obsorb water.

[s_quilicot]

big factor ba ang fully synthetic lubes? from engine to tranny to axle ..?

[speedyfix]

all fluids (except some new coolants) should be replaced at 40k intervals. some things like atf can be done even sooner at 20-30k intervals.