I just had my automatic transmission rebuilt in my 2005 rubicon. I had them install a transmission cooler as well. Anyways my radiator cracked on the way to work. After giving it a good examination I noticed they had bypassed the stock transmission cooler that is built in to the radiator and just ran direct lines from the new cooler. Could this have caused my cracked radiator?
Is it ok to bypass the stock transmission cooler thats built into the radiator?
- Thread starter Rubicon05
- Start date
When you say the radiator cracked, what exactly do you mean? Where was the crack located?
When I installed my aftermarket cooler I kept the radiator in the loop, and added to the existing level of cooling, which in my mind is a better approach.
I'm not sure if bypassing the radiator would hurt or not (I'd guess no).
When I installed my aftermarket cooler I kept the radiator in the loop, and added to the existing level of cooling, which in my mind is a better approach.
I'm not sure if bypassing the radiator would hurt or not (I'd guess no).
JPNinPA
Active member
I highly doubt them bypassing the radiator cooler did cause the crack unless they did something to stress or fatigue the metal. As asked where is the crack? Bottom to top? Personally I'd keep the radiator in the loop should the fan go on the other or it get caked up with mud. The idea of a transmission cooler is supplemental cooling.
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Is it the plastic tank that cracked? I have seen that more than once, plastic does get brittle over time from repeated hot/cold cycles.
One other thing to check; make damn sure you do not have a head gasket starting to go. my nephew just had this on his 02 Grand Cherokee, (4.0) compression is much more than rad system pressure, and radiators are only built to handle what is listed on the radiator cap, engine compression can be 8X that.... so that'll find the weak spot real quick.
I have his engine apart and at a machine shop as we speak, as a result of the blown head gasket (he ran it too long like that, melted several pistons too/ nother story)
To answer your original Q, no, unless they cracked the tank wrenching the fittings loose from the trans cooler within the radiator, no, removing it from the loop will not cause (radiator) failure. If that were the case they would have noticed the leak "right away" and you'd have gotten another phone call while they still had it in the shop, if you get what I mean.....
I know that many transmission shops will do as they did to yours as a sort of "standard procedure" when a major trans failure happens as the burnt up clutches circulate thru the system and settle throughout, sometimes clogging the included transmission cooler. This would lead to a repeat failure-fast. I personally flush (and utilize) the original radiator-trans cooler within the system. If I find one clogged, I may add another cooler but I also replace the radiator. I have never had luck with a trans lasting very long on "just" an external cooler by itself. I would want to add in a trans temp gauge
("t" it into one of the cooler lines) to keep an eye on fluid temp. Anything over 200* is definitely bad for the trans.... (and coolant temp does not necessarily equal trans fluid temp)
One other thing to check; make damn sure you do not have a head gasket starting to go. my nephew just had this on his 02 Grand Cherokee, (4.0) compression is much more than rad system pressure, and radiators are only built to handle what is listed on the radiator cap, engine compression can be 8X that.... so that'll find the weak spot real quick.
I have his engine apart and at a machine shop as we speak, as a result of the blown head gasket (he ran it too long like that, melted several pistons too/ nother story)
To answer your original Q, no, unless they cracked the tank wrenching the fittings loose from the trans cooler within the radiator, no, removing it from the loop will not cause (radiator) failure. If that were the case they would have noticed the leak "right away" and you'd have gotten another phone call while they still had it in the shop, if you get what I mean.....
I know that many transmission shops will do as they did to yours as a sort of "standard procedure" when a major trans failure happens as the burnt up clutches circulate thru the system and settle throughout, sometimes clogging the included transmission cooler. This would lead to a repeat failure-fast. I personally flush (and utilize) the original radiator-trans cooler within the system. If I find one clogged, I may add another cooler but I also replace the radiator. I have never had luck with a trans lasting very long on "just" an external cooler by itself. I would want to add in a trans temp gauge
("t" it into one of the cooler lines) to keep an eye on fluid temp. Anything over 200* is definitely bad for the trans.... (and coolant temp does not necessarily equal trans fluid temp)
I also have a 78 Plymouth Fury 2 door hardtop, only has 52K original miles on it. I bought it 8 years ago with 38K on it. I'm the 2nd owner of it ever. The last couple summers I have had problem with it running hot on me, I know its radiator is plugged internally. I flushed it many times, even pulled it and laid it on its back, and filled it with a couple of different chemicals, dissolved alot of scale and got it out. Helped tremendously but it still climbs a little higher than it used to when I get on the highway and cruise over 60. keep it below that and it stays cool. so I know the radiator still has some deposits in it that I have not been able to break loose.
Anyways, the point of all that is related to the above post about "everything comes that way now". I have looked everywhere and I have 2 choices; a custom made all aluminum unit or a stupid assed aluminum/plastic piece o' crap that would look more at home in a toyota.... I refuse to buy a toyota or any other imported car, and I sure ain't puttin a plastic/aluminum POS radiator into my old car. watching/waiting for an old-stock Modine or something to show up at a swap meet or Ebay for it.
also on that subject; I know that this is the type of radiator that came in my 97 TJ when it was new, and my XJ's when I had them, but in my TJ and one of my XJ's, at one time I was able to get (and did) a conventional copper/brass radiator for them, and did so.
On the TJ, I have had it long enough to need to replace the radiator again and am pizzed that the 2nd time I could not get a copper/brass unit for it.... I HATE plastic tanked radiators.
Anyways, the point of all that is related to the above post about "everything comes that way now". I have looked everywhere and I have 2 choices; a custom made all aluminum unit or a stupid assed aluminum/plastic piece o' crap that would look more at home in a toyota.... I refuse to buy a toyota or any other imported car, and I sure ain't puttin a plastic/aluminum POS radiator into my old car. watching/waiting for an old-stock Modine or something to show up at a swap meet or Ebay for it.
also on that subject; I know that this is the type of radiator that came in my 97 TJ when it was new, and my XJ's when I had them, but in my TJ and one of my XJ's, at one time I was able to get (and did) a conventional copper/brass radiator for them, and did so.
On the TJ, I have had it long enough to need to replace the radiator again and am pizzed that the 2nd time I could not get a copper/brass unit for it.... I HATE plastic tanked radiators.
So I replaced the radiator and drained the oil to check for water. The radiator is the plastic poc but for the price I couldn't beat it. The oil had no signs of water in it thankfully. The only thing that is worrying me is that the top of the radiator is getting super hot in the same place it cracked previously . I fell as though the fluid is not circulating properly. which is causing it to get super heated where the water should be exiting the radiator and into the engine. I checked the return hose and it is hot but not as hot as the hose exiting the radiator. Could this possible mean the water pump is shot? If so would this have caused the last radiator to crack like it did?
JPNinPA
Active member
The water pump draws the coolant out of the radiator bottom and forces it into the engine. It fluid exit the engine at the thermo housing back through the radiator and through the heater core. The lower hose drivers side should be cooler and the upper hose will be hot especially when the thermo opens. If you were super heating the coolant the pressure would rise and more would push past the radiator cap into the resivor. You will (should) always have some current in the resivor .
What temp thermo are you running? What mfg and part number?
Are the two lines to the heater core the same temp if you put the cabin heater on hot and fan high temp?
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