To Flush Or Not To Flush

[N J]

I know there is much talk on the site about tranny flushing and I've noticed that some people do not like the dealer's "high pressure" flush. I just wanted to know why this is so?



I was told by a local mechanic that you can manually drain the fluid yourself and don't need the high pressure flush. Is there any truth to this???



Thanks

 

[Dreman]

Some of us believe in the "change a little bit more often" approach. If you have to change the trans. fluid every 30,000 miles, you can get it flushed at a dealer or shop, or you can change half of it every 6,000 miles. Even though you only get half of the fluid the first time, you will get half new and half old the next time, and three-fourths new and one-fourth old the next time, and so on. Even though you get less of the old fluid each time you change it, you will still get a little bit more of that old fluid out. The percentage of old fluid changed this way is probably the same or better than having it flushed once every change interval.



The advantages are many.

One, no one else is messing with your truck. You don't have to go to a shop.

Two, the cost is spread out over time.

Three, your fluid is more consistently fresher throughout the life of the transmission.

Four, it's easy to go ahead and change the filter when the pan is already drained.



Just change the filter on the regular change interval, and change the fluid more often. Just remember to add a drain plug to your pan when you are changing the filter, and it will be a lot easier. If you are not mechanically inclined, get a shop to add a drain plug to your transmission pan when you have it in for service. If they object, take it somewhere else.

 

[Ben Poche]

Flush made a big difference on mine

 

[Johnny O]

Late-model Ford automatics simply won't last if you don't flush them every 30k. My sister never did in her Explorer, also her and hubby trailered the Harley to FL a couple times, tranny was toast by 80k. Taurus trannys may not last regardless. :lol:

The flush thing is fine if you do it regularly, BUT some shops won't do it on high-mileage cars because it can break stuff loose and cook the tranny. It happened to my Lincoln. Over 100k, I'd say just do a pan drop since the trans is on borrowed time by then anyway.

 

[Dreman]

I must borrow a lot of time, then. My GMC has 193,000 miles on the original Trans. Our Trac has 83,000. Our previous cars went over 200,000 on the original transmissions (90 Celica and 95 Contour).



With regular maintenance and care, there's no reason the trans. in our Trac shouldn't last that long as well.

 

[Dre L]

I had the flush done at 25K, dropped the pan and changed the filter at 40K, flushed again at 50K, no issues, didn't really notice any difference except for the first flush.

 

[Andy Szkutak]

The shifting feel in my tranny has been worryin me for the last 40k or so, so ive been changin the filters and fluid about every 15k to be safe, cuz i cant afford a new tranny or rebuild with college....



Andy

 

[Johnny O]

The shifting feel in my tranny has been worryin me for the last 40k or so

Could be just the computer that controls the shifting. Disconnect the battery for about 15 minutes, then see how it shifts. Only downside is you have to reset all the radio stations.

 

[NCDarryl]

I took mine in for the "Flush" at Town & Country Ford in Charlotte NC.



Quoted me $129 for the flush and $89 for the coolant system flush.



Imagine my surprise when they handed me a bill for $348 !!!!!



They "Serviced" the trans ( new gasket + Filter ) so much for the flush !

Quoted price does not include anything (Fluid , $17 additive etc) just labor.



Oh yes... aside from the added cost of antifreeze there was the $30 dollar drain kit !



I'm through with dealerships !!!! Wish I lived near Spartan Ford.



I will always be happy to let Randy drain my wallet. He's the man to order parts from.

 

[TrainTrac]

I will always be happy to let Randy drain my wallet. He's the man to order parts from.

Randy?:huh:



I think you mean Rusty, right?

 

[Richard L]

Nick,

The problem I have and some others have with the Pressurized Flush is the possibility to blowing out seals because of excess pressure. The regular Flush machines only use the pressure from the transmissions internal pump to move the fluid and do not exert any additional pressure. The transmissions pump is slower and requires somone to run the engine at about 1500-2000 RPM to get the fluid moving. Some shops do not want to waste this much time so they use pressurized flush machines. There is no advantange to the pressurized flush machines except for the shop.



Advantages of the flush over dropping the transmission pan to change the fluid:

1. The flush will change about 97%-98% of the fluid. Dropping the pan only changes about 50% of the fluid.



2. The flush connects to the transmission fluid cooling lines at the radiator and future fluid leaks are rare and easy to fix. Dropping the pan to change the fluid often results in transmission fluid leaks that require dropping the pan again and replacing the gasket or sealant.



dreman's method of adding a drain plug and just changing the fluid more often is certainly a viable alternative if you have the time and resources to perform these task. If you are not mechanicly inclined and don't care to do this yourself, you will find the Flush more convenient and less problematic.



As for changing the transmission's fluid filter. There is a myth that the transmission filter needs to be changed like the engine's oil filter. This is not the case. The transmission filter iwll easily last 100K miles if you change your fluid regularly.



Common sense by Just looking at the filter will tell you that something only 1/2" thick or even less, cannot possibly hold 30K miles of debris circulating in your transmission fluid. The transmission filter is like a strainer or screen to prevent larger particles of debris from getting sucked up by the pump and forced through the transmission. When you shut your engine off, and the pump suction stops, the particles trapped on the surface of the filter simply drop to the bottom of the pan where they are trapped by the magnet. Particles small enough to pass through the filter are too small to cause any damage to your transmission.



An engine oil filter must remove combustion by-products. If these combustion by-products are allowed to remain in the oil they can turn into acidic and corrosive chemicals that can quickly distroy your engine. .



Transmission fluids and the filters are not exposed to compustion by-products and therefore do not generating damaging corrosive chemicals. The enemy of transmission fluid is heat. the more the fluid is heated, the more of it's lubricating properties is looses. Heat also converts the fluid to a varnish like substance. This vanish is a bit sticky and any build up can lead to transmission failure. This varnish can also cause particles trapped by the filter to remain stuck to the filter and over time can clog the filter.



If you change the fluid regularly, your filter will last over 100K miles. So it is necesssary to periodically drop the pan and change the filter, but it certainly is not necessary to change the filter every time you change the fluid. It's only done since you have gone to the expense of dropping the pan, you may as well change the filter while it's convenient.





...Rich

 

[Bill Ellis]

Just curious, where does it say in Ford manuals that Sport Trac trans should be serviced at 30K miles? I don't dispute this recommendation but I can't find where Ford told us to do that. Does it depend on the level of service duty? I can understand that regular towing generates more trans heat and might require more frequent service. Is there any statistical data that shows more frequent service will prevent trans failure? Few people get trans flushed at 30K so how come all them vehicles aren't breaking? Show me the numbers!!!!

 

[Johnny O]

I just looked at my '05 book, curiously it says trans fluid flush only for Torqshift and 4R100 transmissions. Every other Ford I've owned since '91 ('91 Lincoln, '96 Escort, '99 Ranger, '02 Ranger, '03 Taurus) called for an ATF flush every 30k, and that's not severe service, that's for everyone. I know few people get a trans flush at 30k and they don't get 100k out of their tranmissions either. Of course they may not keep their vehicle long enough to find out.

Bud of mine owns a transmission shop and he's always REAL busy.

I can virtually guarantee if you don't flush it every 30k it won't break at 35k but it won't make it to 100k.

3 flushes X $129 = $387 over 100k

1 rebuilt transmission = $2500 +/-

My sister never did, and her Explorer's tranny was toast at 90k. Cheap insurance.

 

[Richard L]

Bill,

I had a 2001 Sport Trac and now have a 2003 Sport Trac. Neither manual stated that the transmission fluid needed to be changed at any particular interval. What the manual says for the 30K mile service is to check the transmission fluid and change it if needed.



I recommend that you check your fluid at least with every oil change and if the fluid starts to look dark and/or smells burnt, it needs to be changed or flushed.



...Rich