1970s 75 Eldorado transmission

[Richf1966]

Looking for some guidance, I've been preparing my 75 Eldorado for driving, it had not been on the road for 10 years, I wanted to replace all the fluids. I had purchased the car from out-of-state and had it delivered, when it arrived, I took it for a test drive and everything seemed to work and shift properly. I then put the car in the garage to replace all the fluids. I dropped the transmission pan and removed at least 5 quarts of transmission fluid. I then replaced the filter and added 5 quarts of synthetic transmission fluid compatible with Dexron II/III fluid per the shop manual.

The car was on jackstands, the front of the vehicle was 2 inches lower than the back of the vehicle, so when I started the vehicle and checked the fluid after warm-up, I wasn't getting much of a reading on the dipstick, far below the level line. I just assumed it was because it was sitting not level and that the fluid was more towards the front of the pan. Knowing that I removed roughly 5 quarts, I assumed I would need roughly the same amount.

Today, I took the vehicle down off the jackstands for the first time and started the car, it seemed to shift pretty well from reverse to neutral, to park and back again to drive and so forth. I did have some hesitation on a couple of different occasions while I was testing it, but I assumed it was just the fluid being pushed through with some air. It did settle down and seem to shift fine. I then took it for a test drive-through my neighborhood, I noticed that it seemed to be struggling and acting as if it didn't want to shift at the proper RPM. I was at about 20 miles an hour when I started smelling that friction burning smell, I immediately got back to my house and into the garage. I drove it 6/10 of 1 mile and no more than 20 miles an hour.

Immediately I got a fan on it to cool the engine so I could drop the transmission pan and see what was going on. When I undid the bolts from the pan, I noticed that the fluid was not pouring out the back as I was loosening the bolts from rear to front.

I dropped the pan and poured all of the fluid into a 1 gallon container and it only filled about half the container... 2 quarts.

Where did this transmission fluid go? My question, Is it possible that the torque converter lost its fluid over the years? I know I took 5 quarts out, and I know I put almost 6 quarts back in and I only got 2 quarts out after dropping the pan. Did having the car jacked up 2 inches higher in the rear cause the fluid to drain out in someway from the torque converter (sitting this way for one month), considering there may have been already a shortage on fluid, it was coincidental that I got 5 quarts of fluid which is exactly the amount that is required when changing the filter.

A more difficult question to answer is, did I do any damage to the transmission driving it a half a mile at 20 miles an hour?

Any thoughts from you experienced people I would appreciate. TIA!

[bcroe]

The torque converter holds about 2 of the 3 gallons
of fluid required.  If all that fluid had drained back
into the pan and leaked out over time, you might have
been very low.  At this age any original trans needs to
be out for at least an internal and external gasket
refresh, possibly the hard parts are good.  Bruce Roe

[Richf1966]

Update:

Thanks for your input Bruce, I think I'm out of the woods though. I bought another gallon of transmission fluid. I put the 2 quarts that I had taken out earlier today and added an additional 3 1/2 quarts. That brought the level up to the correct Mark. So I have now put a total of 10 quarts, so the torque converter was definitely low. I then test drove the car, it seemed to shift fine so I decided to bring the speed up to 40 miles an hour, I noticed that the car just felt like it was not wanting to move forward. by the time I got home that burning friction smell was really strong. When I pulled into the garage I walked around and noticed that it was very strong on the passenger side, the right front brake caliper is hanging up. There is no issues with the transmission fortunately for me. I did not Service the front brakes as I thought they were OK when I inspected the pads, apparently I have a caliper needing attention.

[TJ Hopland]

More likely than the caliper having an issue is an internal failure in the hose. They break down internally and start acting as check valves so the 1000+ PSI can get to the caliper but can't return when you release the pedal.   Eldo's seem especially prone to this, must have to do with the way the hose is attached to the balljoint so all the flexing during steering is in the same spot.

New hoses all around should be on your to do list.  Don't forget about the short sections of fuel hose in the back above the rear axle.   

Does yours have rear disc?  I think that became an option in 75.  If it does have em thats also a common area to have issues due to the parking brake mechanism.  IF its got drums its all normal stuff back there, the drums even come off separate from the hubs which make inspections easier.   

[bcroe]

I did not Service the front brakes as I thought they were OK when I inspected the pads, apparently I have a caliper needing attention.

After 10 years the problems with brakes are not going
to be pads and shoes, they are going to be cylinders,
calipers, hoses, and lines.  My 79 has had most of that
replaced twice, the stainless lines only once. 
good luck, Bruce Roe

[Richf1966]

More likely than the caliper having an issue is an internal failure in the hose. They break down internally and start acting as check valves so the 1000+ PSI can get to the caliper but can't return when you release the pedal.  Eldo's seem especially prone to this, must have to do with the way the hose is attached to the balljoint so all the flexing during steering is in the same spot.

New hoses all around should be on your to do list.  Don't forget about the short sections of fuel hose in the back above the rear axle. 

Does yours have rear disc?  I think that became an option in 75.  If it does have em thats also a common area to have issues due to the parking brake mechanism.  IF its got drums its all normal stuff back there, the drums even come off separate from the hubs which make inspections easier. 

Thanks for the info TJ, no my car has drums and I just replaced the shoes the other day when I did the inspection of the brakes. I will now go back and inspect and replace whatever is needed. I did replace the fluid in the master cylinder, I suppose I should check that as well and verify the level. Something I have not done since I test drove it

[35-709]

ALL rubber fuel and brake hoses should be replaced.  Common occurrence to have older rubber brake hoses fail internally and not be at all noticeable from the outside.  Also common for the rubber fuel line hoses back at the gas tank (least inspected, seldom seen) to become porous and at first seep, and then leak, gasoline.  Usually those (3) hoses can be replaced without dropping the tank.     

[Richf1966]

As many of you stated, this is indeed the problem. I replaced the calipers and took the vehicle for a ride, after 12 miles the right front caliper started binding again. I will be removing the hoses to get the proper length today. The story continues.