Fluid leak / help identifying hose? "Red fluid nightmares"

varol1

New member
I have a fluid leak and suspect it's coolant as the reservoir is low. From looking under the engine bay, this hose/cap looks to be saturated - anyone know what it might be?

engine.jpg


Thanks in advance.
 
Last edited:
Register to hide this ad
That looks like the vent line for your front differential if you have 4wd.

Normal level for reservoir when hot is around 1/3 full I think.
Depending on how much has been put in it.

Easy to monitor.
 
Thanks - will check out.

Not sure if it's related, but the top and bottom radiator hoses are also flattened or "sucked in" when the truck's not running. Should I look to replace the radiator cap? The radiator itself was replaced less than 5k miles ago.

image.jpg
 
Yes, radiator cap issue, most likely. Also make sure the vent hose to the overflow tank flows freely while you replace the cap. Use an OEM cap if possible.

As others have said, that oily hose is the front diff breather. It can sometimes burp a bit of gear oil after high speed 4WD operation. It is worth checking the front diff fluid level, but everything is probably just fine with that.

-Charlie
 
3bears is going through that same thing. Backflow back to the radiator is stuck somewhere along the line. Aftermarket caps sometimes work and sometimes don't. Oem ones just work.
 
Gang,

Sorry to say I don't think this is yet resolved.

I installed a new OEM radiator cap from the stealership and, unless the leak is residual, it seems the issue is ongoing.

I found a few drops of fluid underneath and followed it upward. Taking off the shroud, I see what appears to be coolant pooling directly below the radiator.

I plan to dry it fully and take her for another spin, though assuming it's not lingering fluid, is this indicative of a bad radiator? Having read up on the strawberry milkshake prior to purchasing the runner, I had a new OEM radiator installed a year ago at 205k miles (sitting at 213k now).

It's also worth mentioning I have a B&M 70268 cooler installed inline, which the local shop told me failed and which I disconnected from the hoses and capped off. I don't see any imperfections on the cooler and the leak persists, so I don't think that's the issue.

PXL-20210319-030727911.jpg


PXL-20210319-032205651.jpg
 
3bears is going through that same thing. Backflow back to the radiator is stuck somewhere along the line. Aftermarket caps sometimes work and sometimes don't. Oem ones just work.

yes going through same thing, I think I might have solved it, or partially solved. I replaced aftermarket cap with steeler cap, replaced top hose, replaced both hoses to the over flow tank ( the one from radiator and the one inside)

its not sucking as flat as it used to , but still more than i remember my 2000 doing it.
 
Gang,

Sorry to say I don't think this is yet resolved.

I installed a new OEM radiator cap from the stealership and, unless the leak is residual, it seems the issue is ongoing.

I found a few drops of fluid underneath and followed it upward. Taking off the shroud, I see what appears to be coolant pooling directly below the radiator.
That color could be coolant or trans fluid. You'll have to figure that one out...

Oily and fishy smelling = trans fluid
Less oily and sickly sweet smelling = coolant

Could be a leaking clamp or a punctured radiator, etc.

-Charlie
 
That color could be coolant or trans fluid. You'll have to figure that one out...

Oily and fishy smelling = trans fluid
Less oily and sickly sweet smelling = coolant

Could be a leaking clamp or a punctured radiator, etc.

-Charlie

Thanks, Charlie. I have a quart of unopened ATF I can smell but I'm 99% sure it's coolant.

There aren't any hoses above the radiator showing leaks.

What's the likelihood of a punctured radiator? (other than the time I drilled into the radiator on my first car in high school while installing fog lights - true story :doh:). The grill, tranny cooler (however small) and AC condenser all sit in front of the radiator, and the shroud covers the back.

What would be the best way to tell for certain, i.e. am I looking for a visible puncture on the surface or would it be hard/impossible to see given the fins? If the former, I could remove the cooler and condenser to get a better look from the front.

Thanks again.

Edit: I had the shop that performed the radiator replacement give it a onceover this afternoon and they're sure the fluid is ATF, not coolant.. they weren't able to identify the source of the leak and suggested hitting the front end with a proper pressure wash. It's also possible there's still fluid in the aftermarket cooler which I capped the ends of but didn't unmount - I'll probably remove it and figure out how to remount it later if it turns out to be undamaged.
 
Last edited:
Resurfacing this thread as I'm afraid this is still not resolved

What I've done:

  • Replaced radiator cap with OEM
  • Removed tranny cooler and reconnected hoses
  • Had tranny cooler pressure tested at a transmission shop - fully checked out, no leaks

I wiped everything down until there wasn't a drop of fluid anywhere, then waited a few days. Once again, there was a small puddle of fluid under the truck.

Tranny fluid seems to be pooling up at the base of the radiator where the stock cooler sits. I don't think the radiator is punctured since it's not coolant. There's no wetness anywhere above this spot nor along any hoses/clamps. The photos make it seem like it's pooling on the driver side but this is because of the driveway grading; I was previously parked in a different spot and it pooled on the other side.

Driver side (between fan shroud and radiator)
driver.jpg


Passenger side
passenger.jpg


Is it fair to say the stock cooler is faulty? As I mentioned above, the radiator (OEM) is just over a year old and was installed by a trusted shop.
 
An old timers trick, throw a little talcum powder on the area you suspect and see if you can spot the leak. The hose clamp for the atf line going in or out of the radiator may have lost their clamping strength. You can cut just a little hose from the end and reposition it with a new clamp.
 
Resurfacing this thread as I'm afraid this is still not resolved

What I've done:

  • Replaced radiator cap with OEM
  • Removed tranny cooler and reconnected hoses
  • Had tranny cooler pressure tested at a transmission shop - fully checked out, no leaks

I wiped everything down until there wasn't a drop of fluid anywhere, then waited a few days. Once again, there was a small puddle of fluid under the truck.

Tranny fluid seems to be pooling up at the base of the radiator where the stock cooler sits. I don't think the radiator is punctured since it's not coolant. There's no wetness anywhere above this spot nor along any hoses/clamps. The photos make it seem like it's pooling on the driver side but this is because of the driveway grading; I was previously parked in a different spot and it pooled on the other side.

Driver side (between fan shroud and radiator)
driver.jpg


Passenger side
passenger.jpg


Is it fair to say the stock cooler is faulty? As I mentioned above, the radiator (OEM) is just over a year old and was installed by a trusted shop.
I doubt it's the transmission cooler in the radiator. The stock transmission cooler is surrounded by coolant except for the two fittings on the bottom that are external to the radiator. If the transmission cooler were leaking you would have a strawberry milkshake going on in your transmission. Are you sure it's transmission fluid and not coolant?
 
I doubt it's the transmission cooler in the radiator. The stock transmission cooler is surrounded by coolant except for the two fittings on the bottom that are external to the radiator. If the transmission cooler were leaking you would have a strawberry milkshake going on in your transmission. Are you sure it's transmission fluid and not coolant?

Well... I decided to verify and now I'm not sure if I might have the abhorred milkshake.

PXL-20210409-215230646.jpg


Top left is coolant, top right is ATF, and bottom is what's pooling up under the radiator. Coolant and ATF each have their characteristic smells; the fluid in question doesn't seem to have any particular smell.. does that mean the two fluids have mixed? Could it be any other fluid? FWIW, there were no other symptoms the last time I drove it a week or so ago. Shifting was butter smooth, etc. And, the radiator is brand new.

Thoughts?
 
The pink milkshake looks like a milkshake. Red trans fluid + Red Coolant makes pink and milky, as odd as it sounds.

That is a coolant leak. There is no other red fluid that could get on the top of the lower tank. The radiator could have been damaged in transit.

-Charlie
 
I'm not sure I understand your situation fully, but the check you power steering lines/fluid level. The power steering fluid is the same ATF, and I believe the lines run close to the radiator. Mine are pretty rusty.
 
Well... I decided to verify and now I'm not sure if I might have the abhorred milkshake.

PXL-20210409-215230646.jpg


Top left is coolant, top right is ATF, and bottom is what's pooling up under the radiator. Coolant and ATF each have their characteristic smells; the fluid in question doesn't seem to have any particular smell.. does that mean the two fluids have mixed? Could it be any other fluid? FWIW, there were no other symptoms the last time I drove it a week or so ago. Shifting was butter smooth, etc. And, the radiator is brand new.

Thoughts?
Like phattyduck said when coolant and transmission fluid mix it becomes milky and pink. Very similar to strawberry milk or milkshake. I agree with him that it is likely a radiator leak. In order for powersteering fluid to get on the radiator there it would have to spray on a lot of other surfaces in order to reach that so that's not very likely.
 
Thanks - will check out.

Not sure if it's related, but the top and bottom radiator hoses are also flattened or "sucked in" when the truck's not running. Should I look to replace the radiator cap? The radiator itself was replaced less than 5k miles ago.

image.jpg

When I bought mine I replaced the radiator cap as well attempting to fix a collapsing upper radiator hose but then noticed the reservoir level never changed from cool to hot after a good drive. I found out the tubes going from the radiator cap neck to the coolant reservoir were completely clogged with crap due to lack of maintenance by the previous owner. Wire to break up the crud and an air compressor to blow out the lines fixed my issue.
 
Thanks for the additional suggestions, gang.

I decided to check the PS reservoir to rule that out and I was shocked to see the level was below the tip of the dipstick; I topped it off.

I still don't understand how fluid could be collecting at the base of the radiator, especially having not run the engine in over a week. It seems unlikely but I wonder if there are two separate leaks, one in the radiator somewhere and one in the PS lines.

I sprayed the undercarriage with Simple Green yesterday and pressure washed everything from the bottom, which I'm hoping helps to see where any leaks may be. I also read a few threads on the low and high pressure PS lines developing leaks/cracks, so that's what I'm hoping to identify when I take a look later today.

The saga continues...
 
In case anyone is curious how this saga came to a conclusion:

  • I took the truck to my trusted mechanic who ended up spending over an hour at the car wash pressure washing the radiator and condenser with "oil eater" soap - he said there was so much ATF in the fins from when the tranny cooler had failed (had to be from one of the hose clamps since the cooler was pressure tested and checked out).

  • He called out the 'sucked in' radiator hoses which I'd tried to resolve by installing a new OEM radiator cap. It turns out a previous owner had used stop-leak and clogged up the hose going to the radiator overflow reservoir.

  • Thanks to RumHam26 for suggesting to check the PS reservoir since it also uses ATF - sure enough, the level was quite low and I topped it off before mentioning it to the mechanic. He found a small leak coming from the PS return line and fixed it by replacing an 8" section of the hose.
I've named this entire adventure red fluid nightmares thanks to Toyota using the same color fluid for the tranny, power steering and radiator. Brilliant on their part.

Thanks to everyone for all the tips and suggestions.
 

Members online

Forum statistics

Threads
278,312
Messages
3,554,089
Members
248,016
Latest member
Advally Service

Trending content

Back
Top