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Trans flush opinions please, 4eat


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I was just hired at an oil change facility, and i will have access to their equipment, and service for the cost of materials. I wish to flush the trans for the fact that the equipment is at my disposal, and for using my own car to train on the machines.

 

1998 Forester 4eat 240,000 mi on trans with unknown service history. 

 

Pros, cons, and opinions please! I have yet to find out if the machine pumps the fluid through, or it lets the trans pump work it while running. I have searched and found more suggestions for drain and fill 3 times, but this won't be practical in the shop environment, and not practical in my driveway. 

 

The trans runs fine with no leaks or shifting issues. From my searching, the cons i have read would be backflow of fluid through valve bodies and clutches, or particulates breaking free.

 

I just want to do the work as the existing fluid is unknown, the trans works fine, and i want to get another 100,000 miles out of (do the work and forget about it) it since the engine is swapped in with new seals and HG. 

 

I wat ot perform this service since i initially want to do the front and rear diffs at the same time, and use their facility to flush the coolant since i used reclaimed coolant when i installed the engine a few months ago (the rad needs a flush as the old motor had oil and carbon in the coolant)

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The biggest problem with the "flush" is that the new fluid can break loose crud in the trans which gets stuck in the valve body. This can happen whether you use a machine or just change the fluid.

 

Most flush machines just hook up to the cooler lines and feed in new fluid under moderate pressure as the old fluid is pumped out by the trans. The trick is to match the input and output pressures (if its adjustable) so the new fluid isn't pumped in at a higher pressure than what would normally exist in the cooler lines.

 

Another option is to connect the flush machine to the trans and meter the fluid coming out. While it is pumping out, pour in new fluid through the dipstick tube.

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Yes, it was your posts i was reading in the search. Today was my 2nd day on the job and i noticed the machine stored in supply room. It appears to hold 12 qts and it has fittings for most domestic and euro vehicles, and universal fittings for other applications. The drain pit has a quick connect line that connects to either the machine or the car.

 

I  have the day off tomorrow and need to turn in some papers of payroll, so i can take a peek at the machine and find out more aout the model of machine and its procedure if anyone here would have experience with it.

 

By all means the trans is not neglected or the fluids burnt, so i should be ok provided that this method is not 'not recommended' for the 4eat.

 

The facility does have the customer sign a waiver for vehicles over 100,000 mi, and the literature on makes and models points out vehicles with premature or faulty trans issues by design.

 

I've only been there 2 days, 12 working hours, still have to take everything in with what is there and what their services are capable of.

 

I like the idea of adding fluid with the cooler line disconnected and let it drain onto the pit. I'll consider this if the machine is not recommneded. I'll have to be off the clock to service my own vehicle unless i pay the discounted employee price to have it serviced for me. The idea was to exercise their shop procedure to justify using their facility for work i can do myself at home.

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The flushing machine isnt pushing fluid through the transmission any harder then the transmission makes itself. There is nothing wrong with a machine flush. Chemicals however are very very bad. Do not use chemicals in transmission or engines flushes ever.

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I get the impression the machine serves as a reservoir, and the engine running will draw fluid from the machine and pump it into a collection device. I only intend to replace the fluid to 'reset' my service interval.

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A bunch of news stations did reports showing that those machines are likely to cause more problems than they solve as they tend to force the fluid through the trans at far higher pressures than the trans is designed for. Numerous manufacturers have issues technical bulletins indicating that these machines are not meant to ever be used with their transmissions and using them can seriously damage a transmission, voiding the warranty, and costing the customer thousands of dollars. Trans flush at 3:44.

 

Edited by bstone
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