Red puddle found under car this morning

[Jonathan]

I came out to the garage this morning to see that the car had sprung a leak. The fluid now all over the garage floor appears to be red/pink in colour. It is relatively thick, but I say that because I had thought the ATF was quite thin. Lying on the freezing cold concrete all night might have thickened it up though.

I worked on the car yesterday. I was doing front wheel work on brakes and the angle drive. I put the front end in the air and left it on those jack stands over night. I am not aware of it moving at anytime, other than prior to jacking it up and removing the front right wheel when it rocked back and forth slightly when I was loosening one lug nut that was on too tight. The transmission shifter has not been touched in over a month since I took the console out for my stereo work. At that time it was moved through the gears in order to remove the shifter plate covering that part of the console. Battery has been removed since November and it has not been started since. It is cold here now, and my garage tends to stay about 10 deg C above the outside temperature. Since it has been around -12 or -14 deg C lately, the garage may have gone slightly below freezing. I had left a bucket of water in the garage over night that I was using for cleaning and it had not froze to ice.

Any thoughts on where the car might have sprung the leak? Or what to check first, or diagnose, or ultimately repair?

I think what I am seeing in the pictures is the puddle coming from the rear end of the transmission pan. I don't feel it is the drain plug as it is wet above that point. If you see that cable that runs across the car from left to right just behind the drain plug, I did see drops coming off it slowly one at a time. I am wondering if perhaps the pan gasket somehow isn't holding and that's where the leak is from? Does anyone have experience seeing it leak from there? I wonder if by having the car up on that angle over night that it added just a little extra fluid pushing on the sealing surface there and it forced it to open up? Not sure if that is even possible.

I'm all ears if any of you have some ideas.

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[Jeff K]

I had something similar with my auto car when I jacked up one end. It was leaking through the dipstick tube to the tranny. The mount for that tube is pretty flimsy, and one small o ring keeps the seal and one angle bracket.

I guess on normal inclines this is not an issue, but a big incline probably backs up there and allows a leak.

Anyway, that was my experience. I hope this helps.

[Chris 16409]

An otterstat seal works nicely on the automatic dipstick tube. Much better than the o-rings.

[DMCMW Dave]

Usually a big leak like that is the dipstick tube. Also the shift cable can leak, and the leak ends up inside the frame so you get an effect where it appears that the fuel accumulator is leaking ATF. I was thinking that lifting the car may have caused the fluid to run out of the frame all at once but that seems like a pretty big leak for that one.

Did you recently do anything that may have jostled the tube? Is the tube still bracket firmly attached to the back of the engine at the driver side head, or can the tube be moved around a lot at the top? If the bracket is missing, sometime simply checking the fluid will cause the bottom of the tube to start leaking.

The most effective way to find the leak is to get the car on a lift, waste a can or two of brake cleaner getting ALL the oil off, and then finding it as a fresh leak trail. Otherwise it is very hard to determine the source.

Common Auto Trans leak points (there are many:)

Drain Plug
Dipstick tube o-rings
Computer governor connectors (two of them) (that red RTV is a bad sign, they are sealed with o-rings so someone has been trying to fix this, and red RTV is a notoriously crappy sealant against ATF).
Shift Cable (leaks toward the front of the car and inside the frame near the accumulator)
Cooling hoses (usually fairly obvious and doesn't get so much on the trans itself)
Pan Gasket. Avoid the temptation to just tighten all the bolts, that usually splits the gasket and makes it worse.

Uncommon leak points:
Where the automatic part is attached to the differential.
Torque Converter Seal (leak is very close to the engine)

In the interest of completeness:
Differential leak points (this would leak gear oil, not ATF) drain plug, axle seal.

[David T]

It can also be leaking if it is overfilled. I also saw the red silicone. Looks like someone has been trying to fix leaks before. Here would be my plan-of-action. Drain the transmission. Remove the pan. Replace the "O" rings on the switch, dipstick tube, and the connector and the governor. Clean the filter and replace the pan gasket. Refill and check as per the Workshop Manual. Also check and maybe replace the gear oil in the final drive. If you are really ambitious check the vacuum modulator and the vacuum line and hoses, the line pressure, and the shift linkage adjustments. Also the cable to the shift computer, aka the governor. It also wouldn't hurt to clean everything up and watch for any other leaks.
David Teitelbaum

[Nicholas R]

When I had an automatic I had a leak that got worse and worse over time and it was the hoses leading to and from the coolant hose. Just a thought.

[Jonathan]

Thanks for the feedback guys.

Here's what I am thinking:

- Not sure what the story is on the red RTV/silicone. I can't find any old pictures to disprove this, but I think it has been that way since I had my rebuilt shift computer installed. That was Spring 2010 I believe. The only other place on my car I know of the red RTV is on the exhaust manifolds. These were done in August of 2011. But they were done by two different mechanics in two different cities. What is the proper use for the red RTV? Does it have one?

- I am leaning towards the problem being the dipstick tube. I confirmed that the bracket up top in the engine bay by the red handle on the dipstick is in place and it doesn't so much as even wiggle if you move it. It is shown as #2 in this parts diagram.

http://store.delorean.com/c-388-4-5-2-autocasepumpsseals.aspx

- What I did see, from a distance, is a pretty messy, wet and grimey looking area around the bottom of the dipstick tube where it looks like it plugs into the top of the pan. I was trying to get a view of it from the back left corner, peering in with my flashlight. I don't doubt this is where the o-ring seal is not sealing very well anymore. What caused it to leak now I do not know. I don't recall bumping it in anyway in the last day or two. I parked the car at the end of last season and quite possibly checked the ATF level as one of the last few things. Perhaps it has had this leak all this time and it took me tipping the car up at the front to get it to pour out.

- I like the proposed next steps about redoing the seals, cleaning out the pan and filter, changing fluid and all that good stuff. I know you can't buy a replacement filter, but am I correct in assuming all the other gaskets and o-rings are still for sale? So would most cars just have had the standard o-rings provide the seal where you see my red RTV?

- I also really like the idea of going through a can or two of brake cleaner and getting all the grime off of everything. I have wanted to do this for quite some time honestly. I know the reality of it is life would be much easier on a lift, but I don't have one and I don't know of anyone in the area that has one to borrow/use. Pretty much all the shops around here won't let you come in and use theirs to do your own work due to legal issues.

- I think what I will do is finish my stuff on the front of the car, put it back down and then put the rear end up on ramps. Then try my best to clean everything else and get a better look/feel at how things are. Does that sound about right?

[Jeff K]

An otterstat seal works nicely on the automatic dipstick tube. Much better than the o-rings.

Great idea.. thanks!

[David T]

There is a procedure for cutting open the filter, cleaning it, and putting it back together. All of the "O" rings and gaskets are available. Brake cleaner is nasty stuff, I prefer to use Gunk engine cleaner and a garden hose if possible for that type of general cleaning. If you want to really get into it you spray the engine cleaner, let it soak and then brush it before rinsing off.
David Teitelbaum

[DMCMW Dave]

Thanks for the feedback guys.

Here's what I am thinking:

- Not sure what the story is on the red RTV/silicone. ....... What is the proper use for the red RTV? Does it have one?

- I am leaning towards the problem being the dipstick tube.

http://store.delorean.com/c-388-4-5-2-autocasepumpsseals.aspx

- .. Perhaps it has had this leak all this time and it took me tipping the car up at the front to get it to pour out.

- I like ... but am I correct in assuming all the other gaskets and o-rings are still for sale? So would most cars just have had the standard o-rings provide the seal where you see my red RTV?

... ramps. Then try my best to clean everything else and get a better look/feel at how things are. Does that sound about right?

--Red RTV? Or blue or clear etc. - Maybe caulking your bathtub if you don't care about the color. Don't use it on a car at all. Use Permatex "the right stuff".
--The o-ring is part ID #8
--Sometimes it works this way but that appears to be a lot of fluid to have laying above the flange.
--Everything else is available. Some folks put two O-rings on the dipstick tube but one is OK if you pay attention. Use a mirror while installing to make sure it seats in the right place, it is common for the o-ring not to seat into the trans case below the bump in the tube and then you get a huge leak.
--yes

Note that the dipstick tube, pan gasket, and governor connectors are BELOW the fill level of the trans, i.e. they will leak all the time. The hoses, converter seal, and the shift cable only seem to leak if the engine is running, although I could be wrong about the shift cable.