How often do you change your fluids?

[jackb]

How often do you change your fluids?

I flush my brake and clutch circuit annually, and change the oil every two years or so.
Coolant I have not decided a set interval yet, since maintenance drove my last two changes, only a few years apart from each.
My gear oil I realized I have only changed once, back in 2012.

Even though I live in a desert now and humidity/water absorption is not an issue, it's cheap and easy to do the clutch/brake fluid annually, even if it is a little overkill.
Engine oil I don't hit the mileage, but change it due to age.

I'm looking to establish a purposeful schedule for the coolant and gear oil. Coolant is more of a pain in the butt, and the gear oil is *expensive* that I have zero desire to drain/refill it unnecessarily.

What is a reasonable (time based, not mileage based) interval for these changes? What does everyone else do? I'm a big advocate of scheduled/preventative maintenance, but I also don't like wasting time and money for no real reason.

[TheStoot]

I would think that changing the life blood of your engine, your oil, would be more important than changing the clutch and brake fluid. I'd do oil every year and the clutch/brake every 2 years. I drive a lot more than most cause I don't like to baby my car and I love driving it and where I live the weather goes from one extreme to another. It can be over 100' in the summer and in the negative numbers in the winter with salt and snow. I do oil every year, clutch and brake every couple years, coolant every 3 years or so and blinker fluid like every 6 months.

[Michael]

Not to go all David T. on you but the maintenance manual has all the answers to this. Changes based on both mileage and time(which should never exceed 1 year)

My arguments are with several fluid intervals. I do not think it is necessary to replace clutch, brake, coolant, final drive every 7,500 miles or even once a year. I also think 7,500 miles between oil changes is too high(for conventional oil).

I think All hydraulic fluids should be done every 24 months. Coolant every 3 years. Conventional oil once a year or every 3k miles. Another argument is with the auto transmission service intervals. The filter and fluid(according to the manual) should be changed out every year or 15k miles. It's an all metal filter, no paper. Elapsed time should not play into it's replacement, only mileage.

As far as the fluid itself, I do it every other oil change. The 4141 is arguably the WORST automatic transmission even put into a production car. It's ultimate goal is to break. I keep fresh fluid in it all the time.
Every other oil change, I use the same tool to drain oil and trans fluid. Its super easy, and it keep your trans as healthy as it can be.

Several years ago, DMCH released an enhanced service routine and mailed out little service card checklists. I still have mine which I really need to fill out and keep with my owner's manual. I'll see if I can upload a scan of it later.

[David T]

This is where I disagree with Michael. The service intervals were meant for a car driven at least a few thousand miles a year. Because most Deloreans don't see that much mileage, all service must be time based. My guidelines are;
Engine oil and filter annually. If the car is not started at all during the year you can go to 2 years and even further. My outside limit would be 5
Transmission oil Check level annually change if it gets bad (color or smell) Change every 10 (it doesn't wear out)
Auto transmission Same as manual
Brake and clutch fluid every other year regardless of use
Coolant test annually for strength and color replace every 5 years
Windscreen washer fluid remove and replace every 5
Battery load test annually replace every 5 regardless of use or condition
Tires Check air pressure once a month or before a long trip. Replace 7 years past date code, sooner if worn to limits
Wiper blades Replace every 5 or when worn. Use a block of wood to hold up off windscreen so they don't take a set when the car is not in use.
Air Filter One of the few items that CAN be replaced based on use. Every 5,000 miles
Spark plugs, ignition wires Replace as needed
Coolant hoses, water pump, seals, belts, and gaskets for cooling system Every 10 years
Do NOT store the car for extended periods with ANY gasoline. After 6 months it starts to turn into sludge, especially if it contains Ethanol.

These are conservative guidelines. If you follow them you should not have a premature break-down. You can probably extend the times especially if the car is not used and garaged indoors. For long term storage fluids should be drained and the battery removed.

[Michael]

To be fair, most of my routine is mileage or time, whichever comes first.

[jackb]

My responses in red.

Not to go all David T. on you but the maintenance manual has all the answers to this. Changes based on both mileage and time(which should never exceed 1 year)

The manual is pretty crappy in that aspect, I think. It's about impossible to read. That's why I was looking for a general consensus.

My arguments are with several fluid intervals. I do not think it is necessary to replace clutch, brake, coolant, final drive every 7,500 miles or even once a year. I also think 7,500 miles between oil changes is too high(for conventional oil).

I think All hydraulic fluids should be done every 24 months. Coolant every 3 years. Conventional oil once a year or every 3k miles.

Pretty reasonable.

As far as the fluid itself, I do it every other oil change. The 4141 is arguably the WORST automatic transmission even put into a production car. It's ultimate goal is to break. I keep fresh fluid in it all the time.
Every other oil change, I use the same tool to drain oil and trans fluid. Its super easy, and it keep your trans as healthy as it can be.
Another argument is with the auto transmission service intervals. The filter and fluid(according to the manual) should be changed out every year or 15k miles. It's an all metal filter, no paper. Elapsed time should not play into it's replacement, only mileage.

I've got a manual. And all my other vehicles I've owned my whole life were either an automatic, or when manual, not owned long enough to go based on time.

Several years ago, DMCH released an enhanced service routine and mailed out little service card checklists. I still have mine which I really need to fill out and keep with my owner's manual. I'll see if I can upload a scan of it later.

I'd love to see this if you can find it.

This is where I disagree with Michael. The service intervals were meant for a car driven at least a few thousand miles a year. Because most Deloreans don't see that much mileage, all service must be time based.

I *average* about 1,500 miles a year. Ballpark. I'd like to bump it up a it more as time allows now that my kids are turning from babies to young boys, but it'll never see daily driver mileage. All maintenance will still end up being time based.


My guidelines are;
Engine oil and filter annually. If the car is not started at all during the year you can go to 2 years and even further. My outside limit would be 5
Transmission oil Check level annually change if it gets bad (color or smell) Change every 10 (it doesn't wear out)
Auto transmission Same as manual

How does the gear oil not "wear out"? Obviously it's not getting any contamination from combustion, but doesn't heat wear break it down as well? Of the trans doesn't get hot enough to do that?

Brake and clutch fluid every other year regardless of use
Coolant test annually for strength and color replace every 5 years
Windscreen washer fluid remove and replace every 5
Battery load test annually replace every 5 regardless of use or condition
Tires Check air pressure once a month or before a long trip. Replace 7 years past date code, sooner if worn to limits
Wiper blades Replace every 5 or when worn. Use a block of wood to hold up off windscreen so they don't take a set when the car is not in use.
Air Filter One of the few items that CAN be replaced based on use. Every 5,000 miles

All solid.

Spark plugs, ignition wires Replace as needed

Curious, how do you define "as needed?" When it starts running shitty? I just changed those about 3 years ago as part of a general tuneup.

Coolant hoses, water pump, seals, belts, and gaskets for cooling system Every 10 years

You change your water pump preventatively??


Do NOT store the car for extended periods with ANY gasoline. After 6 months it starts to turn into sludge, especially if it contains Ethanol.

These are conservative guidelines. If you follow them you should not have a premature break-down. You can probably extend the times especially if the car is not used and garaged indoors. For long term storage fluids should be drained and the battery removed.

I drive it fairly regularly, but relatively low mileage compared to a regular car. ~1,500 miles a year or so. It is kept garaged.

[David T]

Gear oil doesn't wear out, it doesn't get contaminated with products of combustion or moisture like engine oil. It doesn't get so hot as to break down. The biggest reason to change it is to remove the wear particles (tiny bits of metal) from wear.
Same problem with auto trans fluid. The main reason to change it is because it becomes overloaded with suspended solids. If it starts to smell bad or get dark it is because it has been overheated and needs to be changed. Auto trans fluid also gets loaded with friction materiel from the clutch plates.
Spark plugs and ignition wires seem to last a long time but when they go bad you know it. If you figure they can last 50,000 miles under ordinary conditions of use, it could take 33 years to wear them out at 1,500 miles a year.
You change a lot of things "proactively" especially if you want to avoid breakdowns. That includes water pumps, belts and hoses.
1500 miles a year is not too bad for a car only used on "special" occasions.

My guidelines assume the car is in good condition to begin with, NOT a "rolling restoration". To keep it in good condition, it needs a major "rebuild" every 30 years. Seals, gaskets, rubber parts just don't last any longer than that and still be reliable.Can you ignore that and go beyond, of course you can but IMHO now you are flirting with the strong chance of breaking down and getting stuck on the road. The rubber parts in the fuel tank, the fuel pump, the brake hoses, I could go on but you should get the point, rubber doesn't last forever and the systems with fluids need regular service to keep the car reliable. Some of my guidelines are flexible in that they are opinions and you could stretch them out or compress them due to individual circumstances. The less you drive the car the more it will need service.

[Michael]

Finally found my record log. Again this is something DMCH sent out about 10 years ago so some of the info may be defunct. I need to fill mine out and keep it with the car, especially now since I do most all of my own work. It would be best to print out on card stock and you can see by the text where it folded in the center.

record1.jpgScan0003.jpg

[David T]

You can use that as a guide but it is based off of using the vehicle 7,500 miles per year. I have seen very few guides that base off of age only, not mileage. From my observations, when people buy a collector car, in the first years of ownership they do put some mileage on the car but as the years go by it sees less and less use. During that time the maintenance gets neglected till one day it won't work and then gets parked (not stored). Eventually it gets given away to a relative or sold and the cycle starts all over. Guides like this are nice but how many owners even bother to check their tire pressure or lights? It is a very good idea to at least record anything you do and when.

[Michael]

You can use that as a guide but it is based off of using the vehicle 7,500 miles per year. I have seen very few guides that base off of age only, not mileage. From my observations, when people buy a collector car, in the first years of ownership they do put some mileage on the car but as the years go by it sees less and less use. During that time the maintenance gets neglected till one day it won't work and then gets parked (not stored). Eventually it gets given away to a relative or sold and the cycle starts all over. Guides like this are nice but how many owners even bother to check their tire pressure or lights? It is a very good idea to at least record anything you do and when.

If you had taken the time to read the introductory text on the first page before dismissing it in typical Teitelbaum fashion, you would have seen the English text that explains how this guide is indeed based on age. Mileage is also given as a guide for those who drive more often.

I have however created a new enhanced service guide to appeal to your loyal followers:

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