By on August 27, 2014

 

(photo courtesy: http://forums.bimmerforums.com)

Pick Up The Pace! (photo courtesy: http://forums.bimmerforums.com)

Longtime TTAC Commentator ajla writes:

Hi Sajeev,

I do a more through job at the time of purchase, but every year after I do a drain/refill on the radiator and replace some transmission fluid by using my fluid extractor to vacuum up as much ATF as possible through the dipstick tube.

I know that I’m not getting all the fluids exchanged this way, but my question is how much of a positive impact is this regiment actually having on my cars? Am I just wasting my time? I haven’t suffered a mechanical failure since I started doing this, but I don’t know if that proves much.

Keep in mind that the vehicles I tend to own are 20 to 30 years old.

Sajeev answers:

In theory, fluid changes via modest exchanging of old for new is a great idea.  I’ve done this countless times to my brother’s C5/C6 Corvette hydraulic clutch reservoirs, especially after his ZR1 (that some might remember) lost the clutch on an especially hot afternoon of autocrossing…and I’m far from Jack Baruth around the rubber cones!

But the need for annual coolant/ATF servicing is unlikely: both coolant (even the old green stuff) and ATF lasts far longer than a year, at least double for coolant and more like quadruple for ATF. Assuming modest annual mileage, vehicle age is somewhat irrelevant, unless it’s an old truck regularly towing an overloaded trailer.

For you and your cadre of classics? Do fluid changes like ATF/Coolant every 2-5 years, more often for engine oil (duh) and less for other wear items (brake fluid).

 

Send your queries to sajeev@thetruthaboutcars.com. Spare no details and ask for a speedy resolution if you’re in a hurry…but be realistic, and use your make/model specific forums instead of TTAC for more timely advice.

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43 Comments on “Piston Slap: Sucking At Fluid Changes?...”


  • avatar
    dancote

    I hate being “that guy” … but you must know that regiment (usually associated with troops) is not the same as regimen.

  • avatar
    danio3834

    What ‘jeev said, but I’ll add that replacing only the transmission fluid you can manage to suck out and not changing the filter is somewhat fruitless. If you’re going to service the trans, drop the pan, clean out any debris and change the filter. Without doing that, you’re still leaving the debris in the transmission.

  • avatar
    SCE to AUX

    True, although many of today’s transmissions do not have a changeable filter (meaning they require transmission disassembly, not just the pan). I suspect this is due to them having less fluid logic, and more electronic logic.

    • 0 avatar
      CoreyDL

      This is exactly what they told me at the shop about my M, when I inquired why they didn’t do a full fluid and filter change like I had asked. He said this was not normal for that car, and the standard procedure is to change what fluid they can get from the bottom of the pan, 3 qts., I believe. He said the filter was a laborious process for my car, and you wouldn’t do it until a much higher mileage.

      I had it done in my 01 GS, around 102k miles and it wasn’t that big of a deal (in either costs or time-wise).

  • avatar
    SaulTigh

    I’ve always been a believer in good maintenance but I was blown away at just how much better the Aisin 6-speed in my ’08 MKZ shifts following a flush and fill earlier this year. I let my local Ford dealer do it with their machine. Car had 80,000 miles on it at the time and I don’t intend to go any further than 35,000 miles before I do it again.

    • 0 avatar
      CoreyDL

      Probably not a good idea to keep flushing it. I have never read anything good about that – people have problems down the line.

      • 0 avatar
        SaulTigh

        Please elaborate. I have read that this particular transmission is sensitive to worn fluid, particularly the valve body. It’s pretty clear to me that before I had it done, things were sticking on downshifts. Problem solved with the flush and fill.

        • 0 avatar
          CoreyDL

          I have read about this on lots of different boards, as I struggled with what to do about transmission maintenance on older cars.

          It seems the flush method (rather than drop pan/filter method) is bad because rather than eliminating all the metal shavings and collected bits from the pan and the filter, it blows everything around inside there, shifting it around and leaving debris behind once the process is finished. Shops like flushing because it uses more fluid ($$), and requires much less skill.

          So your problem is solved currently, yes. But contributing to more problems later.

          START DISCLAIMER This is a summation of lots of information I’ve read over the years, and is not a first-hand opinion, as I’ve never had a car flushed (because of what I’ve read). It is not fact. END DISCLAIMER

          • 0 avatar
            George B

            CoreyDL, today transmission “flush” usually means using a fluid exchange machine which uses the transmission’s internal pump to take in fluid from a clean tank and pump out fluid into a dirty tank. I’d be more worried about what’s in the “clean” tank of a machine used on many different types of cars than moving any debris around with the fluid exchange. That said, I’d spend my money on dropping the pan and changing the filter per the manufacturers schedule combined with a DIY partial fluid replacement halfway between the filter replacement interval. Automatic transmission fluid is cheap compared to automatic transmission repair. Just be very careful not to overfill the transmission.

        • 0 avatar
          danio3834

          Most major manufacturers, inlcuding Ford, advise dealers against using solely flush machines to service the fluid in the transmission. just about every manufacturer has a TSB on the subject because that practice has been shown to cause problems as Corey mentioned.

          The correct procedure is to remove the pan, clean, replace the filter and refill. Some places will then do a flush with the machine to exchange the fluid stuck in the torque converter, but a flush alone isn’t good enough and could actually cause problems.

      • 0 avatar
        davefromcalgary

        FYI Corey, the Verano is being onced over by a new service department today, hopefully resolution is forthcoming.

        • 0 avatar
          CoreyDL

          Oh good, maybe they’ll be more competent!

          I had a service at my independent last Friday, and then had a recall performed on my car just yesterday at the dealer. Had a very nice customer service experience there. I enjoyed when they said “Okay, today will be free for you.” Gave me a wash and vaccum and inspection too. And a vanilla latte.

    • 0 avatar
      BigWill

      The flush machines with their own pumps are still out there. As for the newer ones, they’re theoretically better but I’d be concerned about the cleanliness of the reservoir – more specifically that they’re cleaning out the reservoir of fresh fluid between fills so that different transmission fluid types don’t get mixed.

      That said, I have became a firm believer in the periodic transmission flush especially because it’s not a terribly difficult DIY. As part of the first flush I ever tried on our old 1990 Subaru Legacy at 100K miles, I drained the old fluid and it didn’t look too bad. When I flushed it however, I got a bunch of fluid out that looked like brownish-red mud. Flushed it until the fluid coming out was fresh, then topped it off. It apparently didn’t hurt the car any since the transmission still worked fine when we sold it at 170K miles – and that Legacy is still on the road.

      I’ve ended up settling on an annual drain ‘n’ fill then a flush at 60K. For the fluid costs of ~$16/year for drain ‘n’ fill and ~$50 for the flush it’s almost a no-brainer for the extra peace of mind.

  • avatar
    Timtoolman

    I am a firm believer in fluid replacement. My friend (and mechanic) had a ’96 Cherokee that was still running with 241,000 miles when he finally sold it to his nephew. (The nephew wrapped it around a tree two weeks later). I asked how he got such high mileage and his response was, “I changed the oil.” He clarified that statement by telling me he religiously changed his fluids.

    Anyone growing up with mid-seventies cars, knows they lasted 80,000 miles and then you hoped to get a buck from the junk man for them. My wife’s ’96 van had nearly 150,000 when we sold it and my ’05 Hemi Ram has nearly that now. Never a mechanical issue. AT flush goes for around $129. That’s cheap insurance for not having to replace the damn thing!

    Change or flush your fluids regularly.

  • avatar

    Does topping up the oil and coolant, due to a persistent weeping leak count?

    • 0 avatar
      danio3834

      I’ve had beater cars where it certainly did.

      • 0 avatar
        JimC2

        “Does topping up the oil and coolant, due to a persistent weeping leak count?”

        “I’ve had beater cars where it certainly did.”

        Hear, hear! I’ve had beater cars where it counted not only for continuous fluid refreshment but also underbody rustproofing! One way to be sure that your vehicle has this feature is when you begin to carry spare motor oil in one gallon cans. :)

    • 0 avatar
      kmoney

      We did this on my parent’s old corolla. Leaked/burned enough that we never did oil changes, just topped up and changed the filter ever year.

  • avatar
    burgersandbeer

    “Do fluid changes like ATF/Coolant every 2-5 years, more often for engine oil (duh) and less for other wear items (brake fluid).”

    Change brake fluid less often than 2-5 years? I thought brake fluid was two years tops?

    • 0 avatar
      danio3834

      “I thought brake fluid was two years tops?”

      If you’re extremely anal about maintenance or believe everything the dealer service department tells you. No, it’t not a bad thing to do, but cars will be fine on the same brake fluid for longer than 2 years.

      • 0 avatar
        mikeg216

        Disagree, brake fluid is hygroscopic and readily absorbs water. At two years it’s due, unless you are running dot 5 fluid. You can buy the proper tool to bleed your brakes for $25 don’t be that cheap.

  • avatar
    RogerB34

    My service interval:
    Tranny pan removal and new filter each 20k miles.
    Coolant drain refill biannually. Cut with steam distilled water unless original comes mixed.
    Only use recommended type ATF and coolant.

    • 0 avatar
      -Nate

      Pretty much this .

      Flushing is always a crapshoot at best , and a bad idea on older or higher mileage rigs .

      Just topping up the engine oil is folish too as it doesn’t remove the accumulated crud oin the sump , that’s why blistering hot oil & filter changes are so important , few ‘ mechanics ‘ (yeah,right) are willing to touch anything hot these days , they need different jobs .

      Brake fluid should always be pressure bled , these days simple and cheap vehicle specific typ pressure bleeders are under $75 OnLine .

      Mercedes’ have drain plugs on the torque converters .

      -Nate

      • 0 avatar
        Sigivald

        I noticed that up-thread – “flushing out the fluid stuck in the torque converter”.

        Having only ever done transmission changes on an old Mercedes, I didn’t realize that having a drain plug on them was … unusual?

        Evidently it is.

  • avatar
    olddavid

    My current DD (Lincoln) has a drain plug on the torque converter, but when changing ATF on any other vehicle, I determine which cooling line is outflow, and using quart-marked gallon jugs, I add fluid while draining with the car idling. When the ouflow is nice and clean red I am finished. This method empties the bad stuff without difficulty or special equipment. I do this after dropping the pan and changing the filter and cleaning the magnet and pan. I generally use 12-16 quarts, but have the peace of mind knowing all fluid is clean.

  • avatar
    tankinbeans

    What’s recommended for DCTs? Do they require fluid changes at some interval, or gear grease changes? Being a hybrid between manual and automatic I’m curious.

    • 0 avatar
      bball40dtw

      It depends on the transmission. The VW/Audi DSG needs to have it’s fluid replaced every 40K miles. And when they say 40K miles, they mean it. I always tried to get mine done every 35K. The Ford dry clutch DCT transmission is a “lifetime fill” or some silliness. It has less fluid than the wet VW DSG. I say 50K-75K depending on how you drive. The schedule is similar to most other Ford transmissions.

  • avatar
    jacob_coulter

    I think many fluid changes are “wallet flushes” that the dealerships push. My advice is follow your owners manual and use a little bit of common sense.

    I definitely see a lot of OCD type behavior when it comes to frequent fluid changes that I think are just wasteful and do nothing to add life to the vehicle.

    Some people have this idea that if they go overboard on fluid changes, it somehow will make their car run forever.

    • 0 avatar
      bball40dtw

      I would add that sometimes the owners manual interval is too long and that some enthusiast sites have better recommendations. For example, Ford says 150K miles between transmission fluid changes on the Flex/MKT. No way in hell is that transmission fluid going 150K miles, especially on the ecoboost versions. My personal recommendation is 50k-75K miles.

      • 0 avatar
        jacob_coulter

        The kind of things I was referring to were power steering flushes and brake flushes etc every few years. I really think 99.9% of cars could go 100k miles on those and it wouldn’t make one bit of difference.

        Regarding changing the transmission fluid, I have mixed feelings on it. It wouldn’t surprise me if more people screw up the transmission changing it incorrectly than it failing because the fluid lost its additives. But I would lean towards changing it sooner.

        I would love to see a more in depth discussion on lifetime transmission fluid from actual transmission engineers. I’m skeptical of the idea that the “lifetime” fluid is purely marketing, I don’t think anyone buys a car based on transmission fluid change intervals, even though my old school thinking says no fluid lasts forever.

        It wouldn’t surprise me if there’s hard data that the failure rate of transmissions with lifetime fluids is actually lower than ones with conventional fluids and regular service intervals.

        • 0 avatar
          bball40dtw

          I changed the transmission fluid early on my MKT because I think the previous owner towed on occasion, and the PTU oil tends to go from fine to nasty very quickly. While they were in there, I figured they might as well get me some new transmission fluid too. If I bought it new, I probably would have pushed it to 75K miles.

          On my C-Max Hybrid, my expectation is that I won’t have to do any fluid changes besides oil for at least 100K miles.

        • 0 avatar
          WaftableTorque

          I had a 1976 Pontiac Grand Prix with a dealership installed undercoating. It was warrantied “for life” for the original owner. The undercoating had failed within 15 years and was flaking off. Since we still had the original invoice and undercoating warranty information, it was tempting to go back nineteen years later and have them reapply it.

  • avatar
    jim brewer

    When I had my oil analyzed at 8300 miles out of curiosity about the ford oil life monitor and found out how conservative that was, I turned my overweening attention to the other fluids instead.

  • avatar
    krhodes1

    Most driving in the US meets the criteria to follow the manufacturers severe service maintenance interval. So that is what I do. IMHO, most people change the oil too often and everything else not often enough.

    • 0 avatar
      ajla

      FWIW, the “severe” transmission service interval on my cars is 15000 miles and the “severe” oil change interval is 3000/3.

      Plugs are listed at 30K and coolant is listed at 30K/24 months no matter the driving condition.

  • avatar
    Scott_314

    I use a suction tube thing for brake fluid, too damn lazy to bleed them at the wheels. Was thinking about doing it for coolant too.

  • avatar
    AFX

    Suctioning out the fluids ?. I know they do that in the Hood with a siphon hose for the gasoline, but I didn’t know people did it for other fluids too !. Another quick and easy method for gasoline removal is an ice pick into the bottom of the gas tank, and a garbage can lid to catch the gas under the leak. As an example of modern progress in vehicular safety, since the automakers switched over to plastic gas tanks less kids in the Hood have to worry about getting themselves blown up now.

  • avatar
    AFX

    As far as transmission fluid goes, my non-expert opinion is that you’re better off changing it too early than too late, like engine oil. New fluid and a filter is cheaper than a new transmission. Are you people actually changing the fluid yourselves ?. If not you should try it sometimes. You let it go too long and it’s no longer that nice cherry cough syrup red color anymore, it turns into a brown mess that looks more like partially used engine oil. That metallic particulate crap floating around in the internals of the transmission that eventually settles to the bottom of the pan doesn’t help your transmission’s life either. With every car that I’ve owned with an auto transmission they’ve always shifted better right after a transmission fluid change, and the new fluid makes the car feel like it’s gained another 5-10hp too. With old transmission fluid it really does feel like the car has a slushbox, and you’re losing efficiency, with new fluid it shifts harder and pulls harder when accelerating. Maybe it’s additives breaking down in the old fluid, but my guess is that it’s more like the viscosity breaking down and lowering the efficiency of the transmission.


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