Transmission fluid in my radiator?

[krisj]

I just got back from a 2,500 mile round trip from Tallahassee, FL to NYC and back. I noticed during the return trip that when I put on the A/C in traffic my temp gauge would start creeping up. After waiting for the system to depressurize, I opened the radiator and found a reddish brownish paste-like substance has completely contaminated my cooling system. It almost reminds me of jewelers polishing rouge, (if anyone is familiar with that.)

I think I already know what it is and I hope I haven't damaged anything. I suspect that the radiator is internally leaking trans fluid into the coolant causing cross contamination. My very newly rebuilt 4L60E was also low on fluid and has started slipping just a little.

I'm not driving the truck until I get this resolved. My plan is to completely flush both systems and then replace the radiator, hoses and T-stat.

Anyone have any thoughts on this? Here's what it looks like...

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[1997chevydriver]

I would say yes its trans fluid...... Not sure why it turned to paste though..... The internal cooler has a crack in it.

 

[oohunter04oo]

I don't know man. Every time that I've seen transmission fluid in the radiator or Coolant in the transmission it's just looked milky. That just looks like improper maintenance of your coolant system. What does you transmission fluid look like?

 

[1997chevydriver]

I don't know man. Every time that I've seen transmission fluid in the radiator or Coolant in the transmission it's just looked milky. That just looks like improper maintenance of your coolant system. What does you transmission fluid look like?

I have never seen a cooling system like that from improper maintenance, but on the other hand i have never had Trans fluid in my coolant either. I'm just assuming it is due to its red, Trans was slipping and low on fluid(with no visible leaks posted)

 

[badazzbulldog]

that is from dex cool being mixed with a non compatible anti freeze it turns into a red sludge I can almost guarantee thats your issue I have seen it before on a few trucks i've worked on. flush the system and replace with regular antifreeze

 

[1997chevydriver]

Nummy......

 

[bow61509]

that is from dex cool being mixed with a non compatible anti freeze it turns into a red sludge I can almost guarantee thats your issue I have seen it before on a few trucks i've worked on. flush the system and replace with regular antifreeze

that's,what it looks like to me, I've seen in first hand in the grand am we used to have, ended up replacing the entire cooling system as well as flushing it

sent from the eskanalierra lol

 

[oohunter04oo]

I would think the fluid would be mixed together if the cooler was bad. Not just one getting into the other. S10's and blazers where bad about the cooling system looking like this.

 

[krisj]

I don't know man. Every time that I've seen transmission fluid in the radiator or Coolant in the transmission it's just looked milky. That just looks like improper maintenance of your coolant system. What does you transmission fluid look like?

ATF looks and smells fine, however I had to add some fluid and now seems to be shifting better, but I can smell ATF after the truck gets up to Op temp.
I'm really not sure how the PO maintained this truck. I bought it in a rush a little over a year ago. Within 2 months the transmission pump failed and I put the truck in a storage locker while I moved to NYC for a year. Transmission just redone 3 weeks ago.

 

[bow61509]

well if tranny fluid was getting in the radiator, coolant would be in the tranny. I'm still betting something to do with mixing coolants incorrectly. as far as the transmission goes check the rear seal for leaks, common leak and cheap to fix

sent from the eskanalierra lol