Mechanic Help please!! What is the benefit of transmission fluid flush?

Question

versus the benefit of transmission fluid drain?

Flush is more expensive, does it mean it is better for the car?

Answer 1

Wow - a lot of different opinions on this one. Basically, they are right. That is, normally, you do not need a flush. If you want to keep your fluid in good condition, you can drain the half or so occasionally and add new fluid. However, if the fluid is burnt (discolored or smells), has been contaminated, the wrong type has been added or you are experiencing shift problems, a flush is recommended. Just be sure to replace with the recommended fluid. Honda and Chrysler come to mind as having special fluids. I'm sure there are others. But the flushing offered at the shops is expensive (they need to pay for those huge machines). A less expensive way to do it yourself is to purchase twice the amount of fluid required. Idle the engine and remove the trans line that enters the bottom of the radiator and let it drain into a bucket as you keep adding more. This pumps the old fluid through the trans much the same way a flush works. When you have used almost all the fluid, shut the engine off and reconnect the line, then top off the level.

Answer 2

brake fluid should be completely changed when the pads and shoes are replaced. Now for the transmission fluid....whatever the (h)ell you do DO NOT do what you mentioned. You have 294,000 miles on a perfectly good transmission. Do not flush it,do not add any highly advertized wonderful fluids to it--even if its blessed by the pope and the dali lama and the head rabbi. Just leave it alone. Do not change the trans fluid unless it has a very dark brown color. If you do that you can remove the drain pan and replace the filter. But that is all---no flushing. Just put it all back together and a month or week down the road drain the trans from the pan's drainplug and then fill it again. The trans fluid you put back in:: it is absolutely critical that you put back the exact same fluid that you took out.A different brand etc will completely screw up the works. Whatever toyota's owners manual says is what you use. In fact you should go out and buy yhe fluid yourself because I dont trust even the dealer to put in the correct fluid--they have screwed up a lot of transmissions in this way--no matter what they tell you.

Answer 3

I recently replaced the transmission fluid in a 1981 Ford F-100 transmission for the first time at 65,000 miles. in order to replace the majority of the fluid I first changed it in the transmission pan changing the filter and gasket. The capacity of the system was just under 3 gallons and the pan held about 1 1/2 gallons. after doing this I removed the transmission line going to the fluid cooler and attached a hose to it and placed it in a 5 gallon container. I had my wife start the truck and put it in drive. Very shortly transmission fluid started coming out of the hose and into the container. As the fluid collected in the container I added fluid to the transmission filler tube at what I guessed was the same rate fluid was filling the container. I had marked the inside of the container at 2 gallons and when the old fluid reached a little above the mark I had my wife stop the truck engine. By this time the fluid was clean and had pushed most of the old fluid out. A lot cheaper than any shop could do it and since there is no abnormal pressure or solvents used there is no danger of breaking loose these so called trapped particles in the transmission. ...Good Luck...

Answer 4

If your transmission fluid is not too old and is not burnt (changing color), then a drain and refill will refresh what fluid is still in the lines.

If the transmission has suffered from high heat and the fluid in it is changing color then a flush is needed as burnt fluid is not good and you need to remove as much as possible.

If you don't know if the fluid has ever been changed and it is well past the mileage for it, do a flush to be safe. Then if you don't abuse the transmission you should be able to do a drain and fill next time.

Change the filter no matter which you do and open it and look for flakes. A few flakes of material are ok but if there are lots then you may have a larger problem.

Answer 5

Flush is a more COMPLETE fluid change. You are only contaminating your new fluid with the old fluid by merely doing a drain and fill. If you were receiving dialysis would you feel comfortable only having some of your blood cleaned?

This is an expense you will only need to endure every couple of years, over that period of time what is the price difference?

This service is meant to be a MAINTENANCE service only, do not perform or have performed if you are experiencing any shift quality issues.

By the way, many imports no longer have FILTERS, so there is no reason to "drop" the pan unless your investigating a problem

Answer 6

Trans flush replaces 99% of the fluid when done properly where just doing a pan drop and filter change usually changes just half the fluid. My policy at my shop is if you have over 100k on the vehicle and have never had the trans serviced, I wont flush it but will do a pan drop and filter replacement, however if you have 30-60k or so, I would definately have it flushed. You should be able to get a trans flush with chemicals anywhere for 100.00, and a pan drop filter change for an hours labor plus parts so really there is not alot of difference in price. If you do a flush, you dont need to change the filter or drop the pan, however it wouldn't hurt. If a customer wants both done, which hardly anyone does, it would cost around 200.00

Answer 7

I usually advise against doing a flush, especially one where they claim to use any kind of flushing chemicals. A flush can cause problems by breaking sludge loose which can clog up the small holes in the valve body. The BS about flushing out metal particles doesn't make much sense when you consider that there is a filter in most transmissions to catch any debris. Just do a normal fluid change, which usually gets at least half of the total volume.

Also make sure the shop uses the proper fluid, as specified in the owners manual. Many Chrysler transmissions have been ruined by shops using Dexron when ATF+4 is called for. Also, if it's a Jeep Cherokee they are wrong if they insist it takes ATF+4 (even Jeep Stealerships get this wrong).

Answer 8

Fluid drain can refer to suck and fill where they just suck the fluid out through the fill, and then replace it with new fluid. The flush does change all the fluid in the transmission by reverse flush. It's hooked up to a machine and fluid goes through until it comes out clear.

The problem with both methods is the pan is never dropped, the filter is never changed, and you never see the condition of sludge if any on the bottom of the transmission. many manufactures recommend that you NOT flush a high mileage transmission as it can do more harm than good.

Best way is to drop the pan, check it visually, change the filter, and refill. While it's there they can adjust bands if your system has them.

Answer 9

It is better. If you only drain the fluid, there are still tiny metal shaving left inside. A flush will completely clean the transmission and remove all contaminants. This is important because the contaminates that remain behind will increase wear and decrease the life of your transmission.

Answer 10

WHEN YOU DRAIN TYRANNY, SOME OF THE OLD FLUID STAYS INSIDE, SAY LIKE MAYBE 10-20 PERCENT. A FLUSH IS SUPPOSED TO REMOVE JUST ABOUT ALL THE FLUID.YOU SHOULD ALSO CLEAN THE MAGNET AND REPLACE THE FILTER, AND YOU MUST DROP THE PAN FOR THIS