To be clear, you generally advocate for installing in front of the radiator? I think I previously thought you were on Team Derale Under the Jeep.
Bypass radiator when installing Derale kit?
- Thread starter LJ FlexN
- Start date
To be clear, you generally advocate for installing in front of the radiator? I think I previously thought you were on Team Derale Under the Jeep.
The Derale under tub mount is not something I will ever do again under normal circumstances.
Note that the heat exchanger in the radiator functions as both a cooler and a heater for the transmission. Bypassing it will result in a small loss of fuel economy and a bit more wear and tear on the engine due to the much longer warm-up time for the transmission oil. Transmission oil can absorb atmospheric water much like engine oil, so it needs to regularly heat up to prevent moisture accumulation and degradation.
If you do bypass it, make sure you use an oil thermostat to allow it to get up to temperature prior to letting fluid enter the cooler. The thermostat needs to divert the fluid through a bypass and not simply deadhead the flow.
If you do bypass it, make sure you use an oil thermostat to allow it to get up to temperature prior to letting fluid enter the cooler. The thermostat needs to divert the fluid through a bypass and not simply deadhead the flow.
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I know there are those here (or who until recently were here) who were big fans of the under-tub mount but man, it just seemed like something that was begging for trouble, even if you aren't the type who plays in the rocks. I went with this Hayden in front of the rad when I did mine.
But since I have your attention, can you remind us the proper way to plumb them? Is it the input has to be higher than the output? That makes sense, but there's some reasoning behind it, right?
I recently installed the Derale 20561 kit underneath when I removed my Derale 13700 dual transmission cooler that was in front of my radiator. why did I do this?
Where I live (Dubai) its is now extremely hot 42 Degrees C (107+) most days here in summer and I found that the dual level cooler blocked about 1/3 of the air flow through the AC condenser and then the radiator and I was always running my engine hot. To install the dual thickness 13700, I had to grind back some of the inside of the grill as its really thick. I had the 13700 fan connected to an over ride / manual switch in the cabin.
Since installing the 20561 kit, with the automatic temperature controlled fan wired directly to my battery (via my accessory fuse/relay box) and installing a 1250 CFM rated fan in front of the AC condenser, I found that the engine is running much cooler (right in the middle or just below center mark when on highway at constant speed - usually it likes to cruise at 95 km / 60 miles.
Also the 20561 fan is often running after I park during the middle of the day for a few minutes then switches off. I did connect the transmission lines in series with the radiator cooler but without a temperature gauge I really don't can't compare any benefit.
Plus I also have the deep pan kit for the automatic transmission with the extra quart/liter which I expect does some good but is a pain now to change the filter.
As for damage to the unit, my off roading here is almost exclusively limited to sand dunes, and from previous experience of cresting of sand dunes that rubs away the paint, with touch ups each year; I am expecting that sand may build up but also expect that some blasts from my air compressor trigger nozzle will remove most of it. I also choose the 20561 kit as it is underneath the TJ and out of the sun, as most of my past issues of overheating the engine or transmission was at low speeds or when stopped which negated the benefit of air flow through the radiator. Yes I have a new fan clutch with great CFM.
I have also considered installing the Derale electric fan kit (20161) to replace the fan clutch, but not sure that an electric fan has a higher real or actual CFM then the fan clutch - but that's another topic.
Hope that this is useful for someone.
Where I live (Dubai) its is now extremely hot 42 Degrees C (107+) most days here in summer and I found that the dual level cooler blocked about 1/3 of the air flow through the AC condenser and then the radiator and I was always running my engine hot. To install the dual thickness 13700, I had to grind back some of the inside of the grill as its really thick. I had the 13700 fan connected to an over ride / manual switch in the cabin.
Since installing the 20561 kit, with the automatic temperature controlled fan wired directly to my battery (via my accessory fuse/relay box) and installing a 1250 CFM rated fan in front of the AC condenser, I found that the engine is running much cooler (right in the middle or just below center mark when on highway at constant speed - usually it likes to cruise at 95 km / 60 miles.
Also the 20561 fan is often running after I park during the middle of the day for a few minutes then switches off. I did connect the transmission lines in series with the radiator cooler but without a temperature gauge I really don't can't compare any benefit.
Plus I also have the deep pan kit for the automatic transmission with the extra quart/liter which I expect does some good but is a pain now to change the filter.
As for damage to the unit, my off roading here is almost exclusively limited to sand dunes, and from previous experience of cresting of sand dunes that rubs away the paint, with touch ups each year; I am expecting that sand may build up but also expect that some blasts from my air compressor trigger nozzle will remove most of it. I also choose the 20561 kit as it is underneath the TJ and out of the sun, as most of my past issues of overheating the engine or transmission was at low speeds or when stopped which negated the benefit of air flow through the radiator. Yes I have a new fan clutch with great CFM.
I have also considered installing the Derale electric fan kit (20161) to replace the fan clutch, but not sure that an electric fan has a higher real or actual CFM then the fan clutch - but that's another topic.
Hope that this is useful for someone.
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