A mechanic told me power flushing an old automatic transmission can ruin it

[Victor]

He said the pressure can blow out old seals. He recommended letting the pump in the transmission circulate the fluid with the engine running after dropping the pan and cleaning it, but not reinstalling it yet, I guess he puts the new fluid in the cooler lines. When finished he puts on a new pan gasket and filter. He wants $170 to do it his way, compared to $79 to $99 for the chain store type power flushes that use a machine to circulate the fluid but don't even take the pan off to clean it and don't install a new filter.Has anyone ever heard of an automatic transmission being damaged by a power flush? This mechanic is a transmission specialist and rebuilds them, so he might know what he is talking about, or hes bull****tting me.

[jimbyjimb]

I used to do powerflushes at BBC Dodge in Burien, Washington. I never liked them. I saw that thing blow a couple trannies. One was a late-model Intrepid that I did, just was doing it's thing and blew out a seal behind the CV shaft on the drivers side. I think another tech blew out one on a truck, and I know a 700R-4 on an Astro van ate the bullet too, saw that one. I hate those things. I've been considering getting the fluid flushed on my trans too, but due to past experiences I am VERY hesitant. In theory, if the machine is being used correctly, nothing should happen. In theory. I was using that machine to the best of my ability, used it on several vehicles, and know that one transmission blew on me. I know it happened to one other, older, much more experienced technician than I. And the flush service calls for removal/replacement of the pan and filter. If they don't, they're ripping you. They replace the filter AFTER flushing the fluid, so as to clog up the old filter with crap rather than the new one. Alot of times a very small hole can be drilled/tapped in the converter to drain and plug. I wouldn't reccomend that to anyone without extensive knowledge in dealing with torque converters, however. I haven't even looked to see if the Q converter is accessible from underneath yet. So much to do, ho-hum.

[Q45tech]

Don't confuse the shop air powered transmission machines with the BG Machine which adds no pressure but relies on the transmission internal pump to just pump out old and pump in new.

It's the added pressure from the old style machine that does them in.

A replacement bladder in a BG machine cost $1,000 so cheaper machine use an air pump with the attended RISK of the operator not knowing that 30 psi is max for a JATCO where shop air may be 100 psi..........bam a destroyed transmission.

Male techs just like males in general may not read the instructions carefully and do required research!

Now circulating the {PRIMARY STEP} BG Quick Clean SOLVENT thru the transmission for 15 minutes does loosen the clutch wear material and varnish is often hurried or not understood!

The PROPER exhange process and analysis requires a technican familar with JATCO units to achieve best results.

Look of ATF before contemplating the process, timing the exchange with a stop watch and analysis of pressures created by internal pump.

Most importantly is deciding whether to do the entire process again immediately based on color, smell, and taste [if you have the tongue for the job]. Like a coffee or wine taster.

I see many where once is not enough to restore the circulating ATF to perfection.

If you think about it working an oil well or refinery or eating fast food is much worse than tasting/smelling a drop of petrochemical.

However 60ml [4 tablespoons] of 50/50 antifreeze might be lethal [LD25]{LD100 is 1.4ml/Kg of pure ethylene glycol}

Wife poisons 2 with AF:http://www.courttv.com/trials/....html

[maxnix]

Victor, by reading the prevous posts here on transmission maintenance, you will encounter many of the myths and have them refuted.

BG and Sun machines don't use air.

http://www.bgfindashop.com

When you hear these ignorant statements, move on. You are in the company of idiots.

I like to ask these types why they think old expired fluid is better than fresh uncontaminated fluid? If it is so good, why aren't transmissions filled with old expired ATF? And when they say even after several years and several tens of thousands of miles that the fluid is good and doesn't need changing, how do they know when it does? And isn't a little late by then?

Many of these techs like to see brown or black fluid emanating from the transmission so the client feels like he is recieving a valuable service. Unfortunately, it is far too late. ATF is best exchanged before any difference can be determined by human senses. Hence the two year 25K miiles recommendation. An auxiliary ATF cooler always helps.

"Anyone you says they don't think pan drops/filter changes/magnet cleaning are necessary needs to have his credentials checked as they must have skipped transmissions 101 in trade school." - Q45tech

zerothread?id=578

"I've posted this a few times- but the first for this new forum...It is clear that the filter IS NOT CLEANABLE. Even when it is REMOVED FROM THE TRANS AND CLEANED, so how does the writer expect it to be done by a machine. He is either lazy or ignorant (or conditioned by prior customers looking for the cheap way out?)

Check out: (EDIT: Link is not current)

http://www.atcdg.com/TechBulletins/bull_153.htm

This is a tech bulletin from a manufacturer of trans rebuild kits.... they ought to know." - Ardvakus

zerothread?id=503

So much knowledge in the old posts for those who seek it!


Modified by maxnix at 8:55 AM 4/11/2008

[jimbyjimb]

Absolutely right! If the machine does not use shop air, you have no worries. You are also completely right about insructions and so forth. It was the shop's responsibilty to properly educate a 19 year-old entry level technician on how to properly run that machine and furnish him with paperwork to study it's proper operation. Proper training was not facilitated and niether was proper paperwork. I could have gone out on my own and searched for knowledge but at the point they got the machine I was on my way out the door from extremely low pay and no appreciation for a year's hard work. I should have worked at an independant shop, and if I had I would likely still be a tech.

[qship96]

Absolutely right! If the machine does not use shop air, you have no worries. You are also completely right about insructions and so forth. It was the shop's responsibilty to properly educate a 19 year-old entry level technician on how to properly run that machine and furnish him with paperwork to study it's proper operation. Proper training was not facilitated and niether was proper paperwork. I could have gone out on my own and searched for knowledge but at the point they got the machine I was on my way out the door from extremely low pay and no appreciation for a year's hard work. I should have worked at an independant shop, and if I had I would likely still be a tech.

Exactly why I no longer go to a shop for a machine fluid exchange..... I will settle for 85-90% fluid exchange by doing multiple drain/fills {6} myself at home and avoid the pitfalls of allowing a possible untrained person touch the transmission, or worse yet, using an unclean machine to get an additional 5% of the fluid changed out as compared to doing it yourself, to your standards and satisfaction. The $100-150 you save by doing it yourself can be better spent on top quality full synthetic ATF or performing the drain/fills more frequently.

[maxnix]

Personally, I prefer the one time 98% exchange under pressure. Mostly clean is like almost healed to me.

Most BG and SnapOn shops that have the Sun machines have competent ASE running them. One always has to moitor who works on car and how. Sad state of affairs whn dritical jobs are parsed off to less experienced personnel who are paid less. Dealers are the worse offenders.

[qship96]

I wouldnt trust 98% of the places that hang the BG banner flag on their shop wall- most are run down looking gas stations with young {unskilled?} looking neighborhood flunkies working there- wouldnt even trust em to change my oil correctly. Dealers are even worse, as recently discussed by a few newer members here that work/worked for them..... 85% of fluid exchanged CORRECTLY and without doing harm to your car by doing it yourself beats the huge gamble by trusting the local yokels to possibly get another 5-10% of the fluid out.

I dont know a single local BG shop I would let do it FOR FREE rather than the comfort of doing it myself correctly......

[j-mac]

I have 2004 F250 6.0 DSL Super Duty. Had the recommended 90K service done. 300 miles afterwards, thr transmission was trashed. Am in the process of learning if they used the BG transmission Flush. The told me they don't drop the pan and power flush it.Has anyone here ever had any luck dealing with Ford Motor over things like this?

Had a Service Writer tell me the Power flush is not a Ford Factory Authorized procedure. Your thoughts, folks!

[j-mac]

I agree, but wouldn't it required the pan be dropped before the power flush....my service provider did not drop pan.

[maxnix]

BG uses the transmission's own pump so no damage from BG device is possible unless they used gasoline or some other incompatible.

[MinisterofDOOM]

I wouldnt trust 98% of the places that hang the BG banner flag on their shop wall- most are run down looking gas stations with young {unskilled?} looking neighborhood flunkies working there- wouldnt even trust em to change my oil correctly.

I agree here. That's why you shop around and get a feel for who you're dealing with. I went looking for a GOOD shop with a BG or Sun machine about two months ago. I went into a lot of shops, with and without BG banners. Most of them scared me away. I was tempted to actually tell a couple of them that that simple question/answer session scared me so bad I'd never let them near my car.

I found a shop that passed the test, though, and was happy to pay them for the service. In my opinion, transmissions are just too much of a gamble to screw around with. I say do it right or it's not worth doing. I totally understand your point that a little right is better than a lot wrong, but those aren't the only two options (fortunately for us as owners).Transmission damage is just TOO MUCH of the value of a car when it comes down to the repairs, especially with cars as old as ours. Better to go out of your way to do the thing correctly.

[Jesda]

I trust my Infiniti dealer. They let me meet the techs and mechanics and answer all of my questions and concerns. They did a great job doing an ATF change on the Q, using Nissanmatic fluid.

Bommarito also sponsors the Gateway Z Club.

I'd worry about doing any work at a shop that you can't fully trust, even for oil changes.

[MinisterofDOOM]

I'd worry about doing any work at a shop that you can't fully trust, even for oil changes.

THAT's what I was trying to say. As usual Jesda reads my mind and transcribes it more clearly and succinctly.

[subtle_driver]

I'm a mechanic at a shop in RB, we use a BG machine and I was trained on how to use it properly from both the older experianced techs and the owner and the BG rep. himself. We usually don't use chemicals for the flush process as it can free up some sludge that can get clogged in the solenoids or passages. we generally just use the reccomended fluid from the factory service manuals and let it go through the process.

our manchine does not use pressure, it does not use a filter, it has a diaphram that when the old fluid is pushed in from the transmission, it will force the new fluid back in. very simple and affective. ie. it will take longer on toyota's/lexus because of the low pressure they put out from the cooler lines, and other cars take less or more depending on the design. it will flush 15 or 16 quarts of new atf into the trans.

depending on the make and model, we will opt for a trans. filter and drain/refill service or the flush.

I drop the pan on my q45 and change the screen. but next time i will just do a flush with the bg machine or take off the pan and weld on a drain plug.

but we also replace alot of transmissions from cars with 50k-80k miles, simply because they did not perform simple maintanence. its sad, they could have prolonged the life of the trans. 2x just by one lousy fluid change....

even worse for those audi/vw and Beemer and Benz 's that i work on, with there [lifetime fluids] LOL!!! the fluid lasts the life of the component! hahaha! I'm a luxery car tech, and i'm so tired of those cheap luxery car owners who think they have a car that is invincible. lol! i change alot of engines and transmission's in those higher end cars. so sad...

im tired.

[Haitian_King]

Don't confuse the shop air powered transmission machines with the BG Machine which adds no pressure but relies on the transmission internal pump to just pump out old and pump in new.

It's the added pressure from the old style machine that does them in.

A replacement bladder in a BG machine cost $1,000 so cheaper machine use an air pump with the attended RISK of the operator not knowing that 30 psi is max for a JATCO where shop air may be 100 psi..........bam a destroyed transmission.

Male techs just like males in general may not read the instructions carefully and do required research!

Now circulating the {PRIMARY STEP} BG Quick Clean SOLVENT thru the transmission for 15 minutes does loosen the clutch wear material and varnish is often hurried or not understood!

The PROPER exhange process and analysis requires a technican familar with JATCO units to achieve best results.

Look of ATF before contemplating the process, timing the exchange with a stop watch and analysis of pressures created by internal pump.

Most importantly is deciding whether to do the entire process again immediately based on color, smell, and taste [if you have the tongue for the job]. Like a coffee or wine taster.

I see many where once is not enough to restore the circulating ATF to perfection.

If you think about it working an oil well or refinery or eating fast food is much worse than tasting/smelling a drop of petrochemical.

However 60ml [4 tablespoons] of 50/50 antifreeze might be lethal [LD25]{LD100 is 1.4ml/Kg of pure ethylene glycol}

Wife poisons 2 with AF:http://www.courttv.com/trials/....html

I had mine flushed after specifically hunting down a BG shop. I had visited an independent shop before that claimed they did transmissions, but once the guy heard the age of my car, he declined to do it. Must have been used to less hardy vehicles of the same age or younger crapping out.

[Q45tech]

All about the fluid condition examination. If it's dirty, black, slimey, smelly we won't usually do it unless the customers signs a risk document. Even if they sign we may insist on doing it TWICE in a row to make sure all the crud is out. We don't stop until the ATF looks perfectly brand new.

We may also imsist on a pan drop and clean IF there are chunks or metal in the initial pan sample from drain port.

The point is change ATF early and often then the risks are minimal and you will prolong life until something mechanical fails from fatigue.

[maxnix]

I'm a mechanic at a shop in RB, we use a BG machine and I was trained on how to use it properly from both the older experianced techs and the owner and the BG rep. himself. We usually don't use chemicals for the flush process as it can free up some sludge that can get clogged in the solenoids or passages. we generally just use the reccomended fluid from the factory service manuals and let it go through the process.

I drop the pan on my q45 and change the screen. but next time i will just do a flush with the bg machine or take off the pan and weld on a drain plug.

The solution that Q45tech is correctly advocating is the best, keep exchanging and chemically flushing until it is clean as new. Leaving varnish and crud in is no gurantee it won't break loose at a later date!

If your car has the no drain bolt pan, your car must have never been updated, if I understand the early RE04 updates correctly.
Modified by maxnix at 4:26 PM 4/19/2009

[subtle_driver]

The solution that Q45tech is correctly advocating is the best, keep exchanging and chemically flushing until it is clean as new. Leaving varnish and drud in is no gurantee it won't break loose at a later date!

I agree with this, unless it is super old, ie. a toyota corrolla with 200k miles. but it just depends on the car; case to case basis.

If your car has the none drain hole pan, your car must have never been updated if I understand the early RE04 updates.

what update are you talking about?i read all the tsb's on my car and saw nothing about a transmission pan update.do you have more info or a link? is it a warranty repair? that would be cool! please give me more info on this! thanks man!

have you guys ever pulled apart a transmission that has had bg chemicals added when the buildup was too much? even after several flushes. Some of the local Express tire and Firestone repair shops do this flush all day long, and we end up with the cars that didn't make it through the process. the solenoids get jammed and the internal screens and passages get mass build up of contaminents. i would not do it to my car unless it was in decent shape. i don't see anything wrong with the chemical service unless it has been far too long or never had a service done. the screen or filter can't catch everything. sometimes the chemicals will disslodge stuff that accumilated in the filter.

but anyway, if the car has alot of miles and never did a flush and it was my car, i would just do a filter and fluid exchange. and keep doing that every 15k or at least 30k. less chance of a huge mass of crap being dislodged from the chemical cleaner at one time. but thats just my humble opinion.

it really doesn't matter to me what you do, how you do it to you're car, i would do it this way for my personal car thats all. everyone's got a different way of doing their flushes. I'm just a ASE cert. tech, and i'm not a master and still learning; Only been doing my job as a high end luxery car mechanic for 5 years.

man my spelling sucks!

ya get back with me about that update!! don't forget! thanks!

[Q45tech]

Kind of complex inthat some of the EARLY replacement Nissan rebuilds came back with old pans without drain plugs.Some of the brand new transmission held in spare parts inventory had no drain plugs.

By 1994 all the replacement tranmissions had drain plugs.

Non Nissan remans [independent rebuilder] didn't change drain pains. Junk yard trannies may not have drain pans.

Must research dealer documents to see what happened [but they won't differentiate pans].

Updates are just that rolling changes in manufacture without recourse.

[subtle_driver]

Kind of complex inthat some of the EARLY replacement Nissan rebuilds came back with old pans without drain plugs.Some of the brand new transmission held in spare parts inventory had no drain plugs.

By 1994 all the replacement tranmissions had drain plugs.

Non Nissan remans [independent rebuilder] didn't change drain pains. Junk yard trannies may not have drain pans.

Must research dealer documents to see what happened [but they won't differentiate pans].

Updates are just that rolling changes in manufacture without recourse.

hmmm...all i know is my transmission is the origonal unit that came with the car from the factory in 1990. and i have been drag racing and autocrossing and driving it everywhere with no problems. its got a 94 tcu and i reprogrammed the ecu for a higher rev limit and adjusted the vvt and ignition timing and fuel mixture to handle e85. so, i basicly just have a pan that has no drain plug. i guess i'm still gonna take it off and weld on a bung for draining the fluid.thanks for the info on the updates tho! appriciate it! if i see an updated pan at the boneyard, maybe i'll pull it for myself.

[maxnix]

If you don't use FireFox, then install IE Spell Checker for IE7 & IE8.

[subtle_driver]

haha, thanks for the spell check! i need it! I'll give it a try!

[Q45tech]

Have you owned the transmission since 1990? Otherwise how can you be sure?If that Q has orginal transmission [without a rebuild] it may be the only one in US and I'm sure JATCO would like to see it to understand Why and How.

[MinisterofDOOM]

[subtle_driver]

It is original. look, the radiator was replaced half its life ago, that would help with the transmission cooler performance drop as it aged. Thats my theory anyways. Mcar has 118,000 miles. That might help too.

I'm going to work now, doing a timing belt on a 98 Audi with v8, and oil pump on a Audi A4 1.8t. have to drop the subframe, gotta love those cheap oil change places for giving me that one. Oil got cooked and the pickup is clogged with carbon and almost ruined the head and turbo.

[Q45tech]

Well the miniscule 118,000 miles might explain it? Normal people in US drive 12,000 miles per year which would be 229,000 in 19 years.Being abnormal I've driven 322,000 [2.7x more] and am on transmission number 3.

Trannies are speced for 100,000 shift cycles before failure. Due to my high annual mileage the longest I have been able to tolerate a transmission was 8 years.

I agree that no 19 year old transmission should be flushed even with BG system.

[maxnix]

I agree that no 19 year old transmission should be flushed even with BG system.

Care to elaborate? What can happen with a mechanical ATF exchange that couldn't happen with normal operation?

Even in the case it has been mechnically exchanged regularly previously?

[Q45tech]

I should have been clearer don't use BG Quick Clean for transmissions if the transmission has never been exposed to it in 19 years without a rebuild.

The glue that holds the friction material to the metal backing only has a finite life depending on temperature and ph+ of ATF. I believe it is less than 19 years.

Can you say fragile at best.

But as I always point out I change trannies every 8 years max and already have a new Nissan one for my 7 year old unit waiting for the day.

[bullittandy]

I agree that no 19 year old transmission should be flushed even with BG system.

I'm afraid that this is going to unhinge Brian.