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Cadillac Repair/1991 Cadillac Brougham Transmission Cooler Lines


QUESTION: I have a 1991 Cadillac Brougham with the 5.7L engine and the original transmission. I had a new radiator installed by a repair shop this week. On the way home from the repair shop, the transmission failed. It ran for about 30 minutes more or less before failing. Some gears do not work now, including reverse. I am wondering of the transmission cooling lines might have been reversed in the radiator installation. Is a diagram available for these transmission lines?

ANSWER: Hello,

Like this?

I have known about complaints of new radiators failing quite often. The coolant will look black and sludgy if from the oil and white/pinkish if from the trans.
There is an oil cooler and trans oil cooler. One guy told me he went through 5 before he got a good radiator!!!!
Transmission may now be junk. It is pretty difficult to put the lines in the wrong holes because there is not much give being made of steel.

I do not know if that transmission is serviceable or sealed. If serviceable it will have a dip stick.
Here is what you can try to do. Pull the pan and dump it. Add type F Ford fluid. Run until warm and try driving a couple blocks. Drain again and install more type F fluid. What you are trying to do is flush the converter. Do one more time and see how it works.
The type F works better for gripping than the Dexron 3 in this situation.

Or--if an oil change place is capable of flushing the torque converter and trans that would be easier.
coolant/ antifreeze puts a laze on the transmission parts and a mechanic from the day (me) used to use type F for these situations and the trans worked fine for years.

Other than that, you have big problems and my guess is that one of the coolers let go in the radiator.

Good luck!ttp://

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QUESTION: Thanks for the fast response. I check all the fluids you mentioned. The coolant is new, clear, and green. The oil is a little dark, but clear. The transmission fluid is dark red (darker than normal), clear, and has a slight burnt smell.

I have also noticed a transmission fluid leak under the car.

Does any of this make a difference in the possible problem?

Thank you.


Well, it rules out the radiator replacement and the transmission issue was coincidental to the radiator replacement. I answer the questions as accurately as described since unfortunately I am not at the vehicle. Tank contamination in the radiator has been found from my experience to be commonplace because of the inferior quality of Chinese manufacturers.
Fortunately, it sounds like the fluid colors are good and that is a good thing!

I would ask you where the transmission is leaking, but instead, I would ask that you include a good photo in which I could tell you your next step.
You did not tell me the fluid level with engine warm in drive.
If the leak is serious, it will have to be fixed and unfortunately  requires specialty equipment to remove the transmission. The equipment supports the engine while the cradle (front suspension is dropped).
If the leak is just something seeping, you can try a can of transmission sealer and again, I would tell you to drop the pan, change the filter and put type F fluid in it, because you have nothing to lose if the transmission clutches are slipping. Its just putting a bandaid on an imminent problem, but I have gone 10,000 miles doing that.
Good luck!

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Rob Painter


Alarm system questions cannot be answered on this forum. These systems are not what I can answer. Without being physically at the vehicle and not knowing what kind of electrical service has been done on the vehicle, there is no possible way to give an accurate answer over the internet. My expertise is in Ignition/key based anti-theft systems. These issues include GM VATS (resistor chip in key blade) PASSLOCK (MRD)-ignition lock rotation based, no special ignition key and the PKIII Transponder (computer chip in key) systems. These systems are not alarm based and are integral with the starting of the engine. This is why I cannot diagnose alarm problems without physically looking at the vehicle: Alarm systems are a completely different annimal than ignition key/lock based anti-theft system. Many alarm questions come from vehicles 10 years old, and since older, many hands that had been involved over the years.I am an expert in all GM factory (ignition/key based)systems. Alarm system questions pose to many situations beyond my knowledge as to what has been done to the vehicle over the years. Some guy may have actually wired the stereo into the alarm system. Who knows? Over my past 30 years in vehicle wiring repair, I have seen unbelievable wiring disaters done by guys that consider themselves "mechanics." I have seen stereos and alarms intalled using surgical tape. I have seen modules burn up, un-fused circuits, wiring jambed between the doors and even lamp cord used for a starter kill. To answer alarm questions over the internet without examining the vehicle is like asking; What does it take to remove a dent?


Education/Credentials-ASE certified. 11 years with a GM dealer and 17 years with a repair facility dealing with only the repair of theft recovered vehicles.

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