Cadillac Owners Forum banner

1 - 20 of 20 Posts

·
Registered
Joined
·
58 Posts
Discussion Starter #1
My 1988 Brougham 200-4R trans was leaking at the pan gasket, and also from the side seal where the manual selector shaft goes thru the side of the case. Before starting, I sent a sample of the ATF to an analysis lab to check for contaminants - everything checked OK. I try to do as much maintenance on my vehicles as possible myself, so I got started on this job by removing the pan and the filter, and the selector shaft and seal.

While the pan was off, I installed a drain valve in it. Then I installed the seal, a new filter, and then the pan (with a new gasket, of course - I personally prefer the cork & neoprene type gasket). I measured the amount of fluid that was drained, and replaced this amount with new fluid.


I took the vehicle out for a spin of about 25 miles, then drained the trans, using the handy-dandy drain valve. I then repeated this whole procedure. The total capacity of this trans is 11 qts., of which about half comes out with the pan removed (or drained by the drain valve).

According to my calculations, I have now replaced approximately 85% of the fluid, so I have 9.5 qts. of new fluid and 1.5 qts old fluid in the trans. This is probably as good as a professionally performed flush, but I am assured that no contaminats have been introduced into the mix by a flush machine. Also, the trans has been able to become accustomed to the new oil gradually.

My total expenditure for the filter, gasket, seal, and ATF has been about $40. If I did one more drain & refill, I would be down to less than a qt. of old fluid, and 10+ qt. new fluid.

It works for me...
 

·
Cadillac Technician
none
Joined
·
11,051 Posts
Does anyone have information that would lead me to understand why the general concensus is that flushing machines introduce harmful materials into your transmission?
It seems this keeps coming up but I'd like to see what the basis of this point is.
Thanks.
 

·
Cadillac Technician
none
Joined
·
11,051 Posts
Thanks for the link, that looks like some good info, I agree with some of that, but not all for sure.
Not looking to start a debate, just wanted to see what the basis was for this opinion.
 

·
Registered
94 FWB, 93 SDV, 94 FWB (sold), 90 Brougham (sold)
Joined
·
3,730 Posts
If I had a terrible disease and I was very sick, I wouldn't want the doctors to give me a blood transfusion with a needle everyone has used, while at the same time pumping it through me at 45 psi. I'd let the pump inside me do the work, and not use the same needle everyone else did when they were sick.
 

·
Premium Member
2006 STS V8 AWD, '95 Ford Ranger
Joined
·
28,963 Posts
Many years ago the Navy discovered that the major cause of failures in air-to-air missiles was contamination of the hydraulic oil by the machines used during the routine testing process. This testing was done using highly developed and carefully maintained machines but the result was still the same. If a faulty missile full of metal particles were tested the rest down the line would be contaminated as well. The newer Cadillac models (CTS) have a sealed transmission, no dipstick, and are designed to go 150-200,000 miles before someone starts to monkey with it. It would seem that a process of sufficient disassembly to provide adequate draining, cleaning, and replacement of filtering elements would be far superior to circulating the crap from Joe Scooterberry's failed transmission through yours. The only thing a transmission flush throughly drains is the customers pocket book.
 

·
Cadillac Technician
none
Joined
·
11,051 Posts
Well most transmission flushing machines that I have used don't have internal pumps, they use the transmission pump to pass the fluid and just use valves to direct the fluid flow. I am not sure how that would "stir up" a bunch of debris that just driving the car wouldn't.
Also the machines I have used have separate reserviors for new and for used fluid. When the machine is done, clean fluid is in the lines.

I just said I don't agree with all of it. Not saying you shouldn't follow that advice. Transmission flushes are for maintenance on good transmissions, I don't try to use a flushing machine to "fix" one if it's broken. I send it to my heavy duty shop for a teardown.
I don't doubt that there is poorly maintained equipment out there that offers the possibility of contaminating an otherwise healthy transmission.
If you don't like the idea of doing it, then don't.
 

·
Registered
Unicycle
Joined
·
11,009 Posts
90Brougham350 said:
If I had a terrible disease and I was very sick, I wouldn't want the doctors to give me a blood transfusion with a needle everyone has used, while at the same time pumping it through me at 45 psi. I'd let the pump inside me do the work, and not use the same needle everyone else did when they were sick.
yeah, but don't forget after that, when they start changing the flow from normal, to backwords to "reverse flow" it all. :)
 

·
Registered
Unicycle
Joined
·
11,009 Posts
dkozloski said:
Many years ago the Navy discovered that the major cause of failures in air-to-air missiles was contamination of the hydraulic oil by the machines used during the routine testing process. This testing was done using highly developed and carefully maintained machines but the result was still the same. If a faulty missile full of metal particles were tested the rest down the line would be contaminated as well. The newer Cadillac models (CTS) have a sealed transmission, no dipstick, and are designed to go 150-200,000 miles before someone starts to monkey with it. It would seem that a process of sufficient disassembly to provide adequate draining, cleaning, and replacement of filtering elements would be far superior to circulating the crap from Joe Scooterberry's failed transmission through yours. The only thing a transmission flush throughly drains is the customers pocket book.
It's nothing new, the Pontiac Grand Am (atleast the 3400 V6) dosn't have a dipstick either. It is mostly done to prevent idiots from putting engine oil in the transmission or not knowing what to check.

The manual states that it "shoudln't" need to be topped off, but if it does to take it to the dealer where they remove the upper drain plug and make sure the level is at that point.... like on most rear differentials.
 

·
Cadillac Technician
none
Joined
·
11,051 Posts
Dipstickless transmissions include the 4L60 in the Corvette, 5L50 in CTS, SRX, XLR and Catera, also the 4T40 in the J and N carlines for many years now. (I am sure others that I am not remembering right now)
Almost anything with Dexron III doesn't need service for close to 100,000 miles, see your owner's manual of course for recommended intervals.
 

·
Registered
Joined
·
16 Posts
ralphb, can you post some pictures of your drain valve install?
No hurry.. If you happen to have the car up for something.

RD
 

·
Registered
1970 Sedan deVille hardtop
Joined
·
595 Posts
One trick I have heard to change almost all of the fluid is to disconnect the tranny cooling line that pumps ATF to the cooler and run a hose from that to a bucket. Then, get a funnel and enough ATF ready. Have a friend start the car and as the trans pumps fluid into your bucket, add fresh fluid at the same rate. When the fluid going into the bucket comes out clean, have your friend shut the car off.
Probably want to take this opportunity to blow any fluid out of the trans cooler in the radiator, then hook everything back up, check the level and drive.
 

·
Registered
94 Fleetwood Brougham
Joined
·
7,534 Posts
Does GM recommend flush?

No.

I won't. There is a reason they do not. Either destructuve potential or not needed, either way, no need to mess with something that GM does not back.
 

·
Registered
1970 Sedan deVille hardtop
Joined
·
595 Posts
Something occurred to me: I think that the procedure ralphb used should be called the "Rich mans tranny flush". Why? If Minekee or Jiffy-Lube were to do that, it would cost a load more than hooking up their trans flush machine. The extra labor required, plus parts, plus all the additional fluid would really start to add up.
It only costs less because ralphb was smart (and resourceful) enough to do it on his own. Plus, this way you can be sure that the brand of ATF, gasket, and filter you preferr is put in. Go to most places and you'll get generic, bought-in-bulk ATF and the basic, lowest-bidder gaskets and filter. Not nessacarily bad parts, but some of us wouldn't settle for those pieces. Ask for the name brand stuff and you'd better be sure to say you want the empty bottles and boxes or else there is a good chance you only got charged the higher price.
 

·
Registered
Unicycle
Joined
·
11,009 Posts
BluEyes said:
One trick I have heard to change almost all of the fluid is to disconnect the tranny cooling line that pumps ATF to the cooler and run a hose from that to a bucket. Then, get a funnel and enough ATF ready. Have a friend start the car and as the trans pumps fluid into your bucket, add fresh fluid at the same rate. When the fluid going into the bucket comes out clean, have your friend shut the car off.
Probably want to take this opportunity to blow any fluid out of the trans cooler in the radiator, then hook everything back up, check the level and drive.
That, is very effective and is the best way to remove ALL old fluid. I have done that on my cars.

There is no way I would take any of my cars, or any vehicle I may ever own to a Jiffy Lube type place and get a transmission "flush"
 

·
Registered
94 FWB, 93 SDV, 94 FWB (sold), 90 Brougham (sold)
Joined
·
3,730 Posts
No offense to anyone who works at Jiffy Lube, but I think Jiffy Lube has to be the worst possible place you could take your car. The only thing that matters to a Jiffy Lube manager is turnover of cars. They don't care about repeat happy satisfied customers, all they care about is getting another oil change in, and convincing the soccer mom to pay $30 for injector cleaner that'll throw every O2 sensor she's got.
 

·
Registered
Joined
·
58 Posts
Discussion Starter #19
I tried to find an aftermarket drain plug that I could install while I had the pan removed, but I was unable to find any. They probably do exist; I just couldn't find any. Then I remembered that I had a Fumoto valve on hand from a vehicle that I had sold, so I decided to use it. This is a high quality, quick acting brass drain valve with a SS ball valve built in. It has a positive lock in the off position, and these are in wide use with trucking fleets, etc.

If I had found a flush fitting drain valve, I would probably have mounted it in the bottom of the pan, however, the Fumoto valve sticks out a bit, so I decided to mount it at the rear of the pan, just aft of the pan magnet. To get the majority of the fluid in the pan, I raise the front of the car, and it gets all but a few tablespoons of fluid.

It's nice if the pan ever needs to be removed again to be able to drain the fluid before loosening the pan. If time is available, the pan can be drained and left overnight, and when the pan is removed, it is a fairly clean operation.
 

Attachments

·
Registered
Unicycle
Joined
·
11,009 Posts
I like the idea of the quick drain for the ATF....

but really, when changing the fluid the filter should be changed too... since it isn't too often that gets changed, it isn't a big deal to me.

Though, yeah, draining the fluid before the pan comes off would be nice.
 
1 - 20 of 20 Posts
Top