transmission flush....

[Gibson486]

When you get a transmission flush, so you replace your filter? I see references to it all teh time, but no guide actually tells me to replace it.

 

[Eli]

Depends on the car. Some don't have a replacable filter.

A transmission flush usually referrs to hooking the transmission up to a machine that pushes new fluid through it until it runs clear on the other side, which is the most effective method of changing the fluid. You don't get the fluid in the torque converter when you drain and drop the pan, though some cars have a torque converter drain... it really just depends.

 

[Gibson486]

so...if i bring this to a mechanic, will they flush it only or do I have to tell them to replace the filter also?

 

[Eli]

so...if i bring this to a mechanic, will they flush it only or do I have to tell them to replace the filter also?

What car?

It wouldnt hurt to ask. I would let someone knowledgable with your car answer the question here, I probably won't know much about it. I'm just speaking in general.

AFAIK, a flush is usually done without opening the transmission up. I would say that if your transmission has a filter, go ahead and tell them to perform a full transmission service. As long as the fluid is in OK condition, I wouldn't worry about the amount left in the torque converter.

Then again, your car may have a torque converter drain, in which case you would be good to go. A lot of variables here.

 

[chucky2]

The best way to do it is to have them change the filter (if you indeed to have a filter, some trans's only have a metal screen for the large bits) and then do a flush.

A lot of shops when it's a flush, only do a flush, they don't change the filter. Flush's at a stealership should be around $100-$130, with a filter change anywhere from $160-$180.

The most important thing to make sure of is you ensure, prior to letting them do this, that they use the correct fluid when doing the flush; and even stealerships do not use the correct fluid, or even their brands OEM fluid. If for example your trans is spec'd for Mercon V, you don't let them use Mercon and then an additive to "bring it up" to Mercon V spec - this is BS and the cheap way out for them.

Also, you do not need trans flush additive or after flush additive installed. You only should be having straight trans fluid, of the correct certified type, run through the trans, that's it.

Excuses like, 'That's what we've always used', and, 'We've never had a problem', are not acceptable. Wear, that they nor you would ever be able to measure, from improper frictional characteristics from using the wrong fluid, or seal damage from using a harsh flush additive, will not manifest itself (unless it's an extreme example) for many thousands of miles. What would they say if you brought it in and had problems at that point? 'Oh, couldn't have been our stuff, must be something else...'

It's your $$$, both for the flush and for your trans when it dies because they decided on your behalf to take the cheap way out...make sure you check and insist on this stuff upfront.

Chuck

 

[JeffreyLebowski]

I've never done a flush on a transmission. I just drop the pan, change the filer, put a new gasket on the pan, put it back on and fill 'er up.

 

[WhoBeDaPlaya]

I've always done it at a local independent shop I trust. I buy all the filters and fluids and they do it. That way, I can be damn sure it's done right.
And Royal Purple ATF FTW

 

[HarryLui]

What car? Different cars needs different things.

For examples

Saturn S-series Auto: Spin-on filter, drain from drain plug and refill from dipstick hole

Volvo 240 Auto: Filter in pan, 1.5 qt in the pan, you'll have flush the rest out by draining the oil fluid at the transmission cooler line and pour new ATF in from the dip stick hole.

Volvo 850 Auto: No serviceable filter, drain the ATF from the cooler line, and pour new ATF in from the dip stick hole.

Toyota Celica Auto: No serviceable filter, just drain ATF from drain plug, and refill from dip stick hole.

 

[Pacfanweb]

When you flush the trans, you don't replace the filter. But it's pretty well cleaned after the flush, so I wouldn't sweat it.

Flushing is the only way to get ALL the old fluid out of the trans. Doing a service the old-fashioned way, by dropping the pan and changing the filter, only gets usually 4-6 quarts out of there.....a typical car has up around 12. The rest is in the torque converter. Some cars used to (and might still) have a separate drain plug on the converter....but it's still not as good as flushing.

edit: I see Eli already wrote essentially the same thing.

I will add that the machines I've seen don't actually "push" the fluid through the trans....they use the transmission's own pump to do that.

You could theoretically disconnect your transmission lines and get some rubber hose to extend them out the front of the car, get two big buckets and flush it yourself.

 

[deadken]

While I disagree that the filter gets cleaned during a flush, I don't think that you need to change it if you do a flush. Perhaps change it every third or flush (if going by mileage intervals) or every second flush (if going by how the fluid looks).

When you run the car to do the flush, the fluid is circulating and holding any particles against the filter material (which is EXACTLY why it is put there). Certainly none are going to get past the filter and come out with the fluid that comes out during the flush. If the car was off and a piece didn't get entangled in the filter material, it would settle to the bottom of the pan (assuming an internal filter) and only come out if you removed the pan and cleaned it out (at which point, you'd change the filter also).

For what it is worth, I have only done flushes on my own cars in my garage. Just disconnected one of the cooler lines at the radiator and attached a hose from there to a 5 Gal. bucket. Opened up about 8qts of fluid, put a funnel in the fill tube, and started the car. I positioned the bucked so I could see how much fluid was coming out in order to try and match the rate of me adding the fluid. I stopped when the fluid coming out of the hose was pretty 'cherry cough syrup' red and I think I only used about 9 or 10 quarts.

-Ken

When you flush the trans, you don't replace the filter. But it's pretty well cleaned after the flush, so I wouldn't sweat it...

I will add that the machines I've seen don't actually "push" the fluid through the trans....they use the transmission's own pump to do that. ...

 

[DVad3r]

My car has a filter and gasket kit. I bought one online for 30 bucks. Lexus wanted 120 for it from the dealer lulz.

Anyways, according to the people over at the Lexus forums, the best way to do it is to drain the fluid, top it off with new fluid, drive around for a few days, and drain the fluid again, top it off with new fluid, and then put on the new filter/gasket.

I recommend using a high quality fluid, I use Amsoil ATF.

 

[bigi]

Full flush is not recommended in any newer Honda vehicle. Only drain and fill method x 3.

 

[Pacfanweb]

Full flush is not recommended in any newer Honda vehicle. Only drain and fill method x 3.

Does not apply to the flush machines I described, only the pressurized "back flush" machines.

Absolutely nothing wrong with a machine that uses the transmission's own pump to change out the fluid.