[SEVILLE 85]

I try to do as much of the maintenace on my 98 SLS as I can but it needs the trans fluid changed and it is very cold here so I have been considering letting the dealer do it one dealer in town charges 80 dollars to drop the pan and drain it the other will hook it up to a machine that will change all the fluid for 130 dollars.my car has 100000 miles on it I have heard that flushing things is not a good idea but it does get all the fluid out.I cant make up my mind on this any thoughts on this would be appreciated THANK YOU BOB R.

 

[zonie77]

My personal opinion is to go with the pan drop. At 100K there is some sludge/dirt in the pan and throughout the trans. Flushing not only leaves all that, it puts high detergent trans fluid in which will break some of that up and recirculate it. Flushing is also done by reverse flow, which may push dirt under seals.

The only good thing flushing does is gets all the old fluid out. There is a technique (which I've done) of running a trans cooler hose to a LARGE bucket and draining the trans into it, while filling the pan with fresh fluid. This works well but I don't know of any shops that do it.

 

[mcowden]

Yep, I would listen to zonie. The flush does sound like a good idea, but I have to believe that leaving all that crud in the pan and on the magnet is not a good idea in the long term. I would just drop the pan, remove the "hidden" side cover drain plug, backflush the screens, put it back together, fill it up with fresh fluid, drive it and forget it.

 

[buzz]

I had my '98 SLS flushed at 96,000 and so far so good. Now, with 100,000 miles I'm going to finally have the original coolant changed per GM advise.

The trans fluid change was done by a Cadillac dealer, so I hope they knew what they were doing.:worship:

 

[Trench]

Flushing is also done by reverse flow, which may push dirt under seals.

That is only one form of a flush, and the worst one. Whoever invented that should be beat.

Trans flushes are just fine provided they are done right. Before you do so, though, you should find out what system the dealer uses. If you hear anything reffering to reverse flow, then run.

The good shops/dealers use a flushing machine that mainly relies on the trans pressure itself. It's very similar to just disconnecting the lines and running the old fluid into a bucket and pumping new fluid in. Only this machine has a pump to more or less assist the flow (I guess some transmissions have a painfully slow flow rate), nothing more than that.

I work at a dealership that uses that method and my god you won't beleive how many trans flushes we do with a detergent and conditioner. Not one single problem has ever been reported (many of them are high mileage vehicles). Even the use of a detergent has caused no issues.

If you really want to be thorough, you could request they drop the pan and clean any gunk out, then flush it.

Dustin

 

[buzz]

Dustin:

The dealer did take the pan off and pumped a product called "Transflush/Q5F" through the system before adding new fluid. The total charge for the service was @ $120. It was done by the local Cadillac dealer, so I hope they knew what they were doing. The total repair (including an oil change) took @ 2.5 hours.

 

[Trench]

Dustin:

The dealer did take the pan off and pumped a product called "Transflush/Q5F" through the system before adding new fluid. The total charge for the service was @ $120. It was done by the local Cadillac dealer, so I hope they knew what they were doing. The total repair (including an oil change) took @ 2.5 hours.

Doesn't sound like a bad deal at all. I would imagine (hope) they knew what they were doing. But if you have not had any problems already, I would imagine you are safe.

 

[WarrenJ]

Trans flushes are just fine provided they are done right. Before you do so, though, you should find out what system the dealer uses. If you hear anything reffering to reverse flow, then run [emphasis mine . . . . Warren] The good shops/dealers use a flushing machine that mainly relies on the trans pressure itself. It's very similar to just disconnecting the lines and running the old fluid into a bucket and pumping new fluid in.

Very Interesting. On this site, we've all been taught to cut & run after hearing the words "reverse" and "flush" spoken in the same sentence.

If I understand correctly, you are speaking of something more like a "forward" flush? Is this generally available?

Regards,
Warren

 

[Patrick7997]

I had my '98 SLS flushed at 96,000 and so far so good. Now, with 100,000 miles I'm going to finally have the original coolant changed per GM advise.

The trans fluid change was done by a Cadillac dealer, so I hope they knew what they were doing.:worship:

Buzz, I believe it's 5 years or 100,000 miles for coolant.... so you are years overdue. Reading some of the posts about headgaskets will definitely get you off the couch and into the garage to change that coolant....

 

[Trench]

Very Interesting. On this site, we've all been taught to cut & run after hearing the words "reverse" and "flush" spoken in the same sentence.

If I understand correctly, you are speaking of something more like a "forward" flush? Is this generally available?

Regards,
Warren

From what I understand, reverse flushing machines are less common. They are defiantly around, though.

A forward flush is really nothing more than using the transmissions pump to clean itself out. The basic idea is something like disconnecting the lines running to the cooler (if there is one) and placing the output line into a bucket, and placing the uptake line into a large reservoir of fresh ATF. Then you just started the engine up and let the pump pull in fresh fluid as it pushes the old stuff out (which would normally just loop around the system).

The safe flush systems just help this method out a little with an assisting pump.

I forgot to mention that one case where you should NEVER flush your transmission is if you see metal flakes and whatnot in it. It's been shown that pretty much 100% of the time it will kill the transmission almost immediately. Last I knew, no one really understood why.

If your transmission is having issues (no metal flakes), A transmission flush may hurt it, or may help it.


Dustin