Flush n' Fill Kit Question

miklars · 11-20-2009, 04:03 PM

I just received my CSF 3-row and will be installing tomorrow. I plan on putting on the Prestone Flush n' Fill Kit so I can flush my radiator a little easier in the future.

I'm a little new to cooling systems in general and how they work. When I put on the backflush valve/"t", do I need to perform any type of flush pre-radiator install; or right after installing the radiator but before putting 50/50 coolant in? I guess I'm not 100% clear on whether this type of kit just flushes the radiator itself or if there are additional lines that could need flushing? I don't want to waste unnecessary time flushing out something that doesn't need flushing! BUT if there IS some type of sludge/grime in there I want it out before it gets into stuck inside the new radiator!

FYI - I haven't noticed any coolant muddying or overheating issues, just sprung a pinhole size leak/crease in the area where the alum. meets the plastic tank (upper left-hand side of radiator if facing the jeep - basically right across from the battery). Started hearing a hissing sound when I would shut the jeep down and saw the coolant fizzing out.

**Kettles** · 11-20-2009, 04:22 PM

Well if your replacing the radiator I would flush stuff while you have the old out before you put the new in. I would run water through the block and the heater core, both directions a few times. Should get all the loose stuff. Dont need the prestone kit for that. But it would be handy for later flushes after it is assembled.

miklars · 11-20-2009, 04:27 PM

Sounds good, I'll check the stickies for these processes, but if anybody has some solid links to instructions for performing these flushes, I'm all ears.

I take it I would do this with the engine running and the heater on full blast?...

Thanks!

**Kettles** · 11-20-2009, 04:36 PM

The heater core always has water flow so it doesn't have to be on to flush the core. and I would NOT run the engine with the radiator out. I meant just use a hose or something and run water though the block from the lower radiator hose to the thermostat and vice versa, running water both directions is the main key (same with the heater core). You can also just install the radiator, fill with straight water, and then follow the instructions on the prestone kit. THen when you done fill it with 50/50.

**tjwalker** · 11-20-2009, 05:25 PM

Use distilled water for best results if you're mixing with concentrate; less deposits in the cooling system. Premix 50-50 already uses good water.

I would agree with the above advice of flushing block and heater core while you are into the mess. Go easy on the heater core; real high pressure has been known to cause damage to it.

Another thing to consider while you are replacing the radiator is to install a new thermostat. I have had the best luck with JEEP oem 195 degree stats.

hubs97xj · 11-20-2009, 05:29 PM

Does the 96 have the heater control valve? If it does, he'd need to run the heater to flush the core, unless he connected directly to the core.