Flush after or before new radiator install

[JeepinTJ99]

Kind of self-explanatory.

I'm about to install a new OEM radiator b/c my original (after 85K miles) has given up ... pet**** and crimps at the top are leaking.

I want to flush the whole system out. Should I do the flush before I install the new radiator or after? I just don't want any deposits etc clogging up my new guy.

And, as far as I know, these are the correct procedures for a flush, correct?:

1. Cold engine. Open radiator cap. Drain coolant via pet**** on bottom of radiator.

2. Refill radiator and overflow bottle with distilled water. Run engine to operating temperature with heat on full blast.

3. Drain water via pet****. Repeat draining and refilling with distilled water until the water drains clean.

4. Refill radiator and overflow bottle with coolant/antifreeze. Run engine and check for leaks.

Sound right to you?

Thanks for the help,
~J

[Pillswoj]

I would flush before the rad install. You may want to do a chemical flush to to really clean it out.

[CCJ]

Originally Posted by JeepinTJ99

Kind of self-explanatory.

I'm about to install a new OEM radiator b/c my original (after 85K miles) has given up ... pet**** and crimps at the top are leaking.

I want to flush the whole system out. Should I do the flush before I install the new radiator or after? I just don't want any deposits etc clogging up my new guy.

And, as far as I know, these are the correct procedures for a flush, correct?:

1. Cold engine. Open radiator cap. Drain coolant via pet**** on bottom of radiator.

2. Refill radiator and overflow bottle with distilled water. Run engine to operating temperature with heat on full blast.

3. Drain water via pet****. Repeat draining and refilling with distilled water until the water drains clean.

4. Refill radiator and overflow bottle with coolant/antifreeze. Run engine and check for leaks.

Sound right to you?

Thanks for the help,
~J

Don't know much about the procedure but I wouldn't flush radiator before the new one is installed. I would remove rad fluid out of old one. Then remove the rad completely. Inspect hoses/lines, ect... Install new one. And fill er up with rad fluid.
If you felt like making sure you got all the old fluid out of the lines then I suppose flsuh the new one to make sure you clear the lines but really I don't think that little amount of old rad fluid that is stuck in the lines will do any harm if you decided to not flush it out this go around and simply fill up the new rad with new rad fluid and then later, during the needed interval, flush the whole system.

Just curious, why did you not get an aftermarket aluminum rad?

[Bigbob]

Yes and Yes.

If you think you may have a lot of crud in the block then drain it, put a cleaner in it and follow the directions, drain it. If the radiator will hold water long enough flush it. Being the Jeep is 10 years old I am guessing you want new hoses as well. Remove the radiator and top hose/thermostat. Hook the garden hose to the lower hose and flush again. Remove the heater hose at the engine and flush that as well. Any and all original rubber pieces (hoses) should be tossed. They may look good and only have 25,000 miles on them, but they are 10 years old. Replace them and the thermostat.

[CCJ]

^Or what he said. lol

He seems to know better then me. I trust Bob's posts.

[GOLENJEEPTJ]

If you do decide to run a radiator flush,just use the garden hose for all your flushing needs. You don't need to use distilled water until flushing is complete.When you have decided water is running clear,drain system, then add your mixture of distilled water and coolant! Good luck! It's an easy task.

[JeepinTJ99]

Thanks for the help guys ... I can't decide whether to use hose water or a special cleaner. It definitely hasn't been flushed since I've owned it (from 32K miles until now at 85K miles) so I want to do the best job I can.

I forgot to mention about "burping" the system for about 20 minutes after the last step ... basically just letting the engine run with the rad cap off to let any air escape the system.

And thank you for reminding me ... and am going to replace all the hoses (it's just 2 right?), the thermostat with an OEM one, and also the belt since mine's getting squeeky (it's never been changed, either). If anyone can point me in the right direction on how to change the belt on my year that'd be great ... I know there's no tensioner so I have to remove an accesory, correct?

Thanks again,
~J

[CCJ]

I'd run cleaner. At least that's what searching came up with for me. As far as hose numbers, I'll wait to see what others say as I'm not sure.

[erickpl]

My radiator, t-stat, and hoses are all new, but in the winter months, it just doesn't heat up very quickly at all. Summer it doesn't overheat, so I'm thinking my heater core is a bit nasty or I have excess air in the line.

I can work on getting the air out by burping it (as described above), but I'd like more specifics on this cleaner bob mentioned and a process for flushing the core if you guys could provide it. Getting warm air is kinda nice to have when it is 16 degrees out (and this is freakin' Alabama!)

[GOLENJEEPTJ]

You run the cleaner as per instructions, then you can use the garden hose.

[JeepinTJ99]

Originally Posted by erickpl

My radiator, t-stat, and hoses are all new, but in the winter months, it just doesn't heat up very quickly at all. Summer it doesn't overheat, so I'm thinking my heater core is a bit nasty or I have excess air in the line.

I can work on getting the air out by burping it (as described above), but I'd like more specifics on this cleaner bob mentioned and a process for flushing the core if you guys could provide it. Getting warm air is kinda nice to have when it is 16 degrees out (and this is freakin' Alabama!)

Now that sounds like your heater core needs to be cleaned out. Plenty of those came into the dealership when I worked there ... just never stuck around to see the fix. Is that a seperate, flushable system or is the heater core tied into the cooling system?

[GOLENJEEPTJ]

[quote=JeepinTJ99;6401927]Thanks for the help guys ... I can't decide whether to use hose water or a special cleaner. It definitely hasn't been flushed since I've owned it (from 32K miles until now at 85K miles) so I want to do the best job I can.

I forgot to mention about "burping" the system for about 20 minutes after the last step ... basically just letting the engine run with the rad cap off to let any air escape the system.

And thank you for reminding me ... and am going to replace all the hoses (it's just 2 right?), the thermostat with an OEM one, and also the belt since mine's getting squeeky (it's never been changed, either). If anyone can point me in the right direction on how to change the belt on my year that'd be great ... I know there's no tensioner so I have to remove an accesory, correct?
Isn't there a long adjustment bolt under the power steering pump like on XJs?

[garybattles]

On a couple of my previous vehicles, I bought and installed a flushing kit. Required cutting a heater hose (I think) in the engine bay and installing a tee type fitting that had a screw-on cap. Take the cap off, screw a garden hose onto the tee, unclamp one of the other hoses (can't remember which one), turn on the water, start car, turn on heater and run until water comes out clear. Was pretty handy before 50,000 mile fluid, when we had to change the fluid a lot more often. Have no idea of the price of the kit, but it was pretty cheap.

[JeepinTJ99]

Thanks for all the helps everyone. I'll be doing the flush before I do the swap.

I just picked up the OEM radiator today from my buddy at the dealership for $190. I just need a little help getting all the stuff I need. I want to replace EVERYTHING ... inlet and outlet hoses, thermostat, and drain ****.

This is from Advance Auto:

- Dorman Radiator Drain ****: $5

- Stant Radiator Cap: $6

- Lower & Upper Coolant hoses: $40

- OE replacement Thermostat (I NEED HELP - I DON'T KNOW WHICH TEMPERATURE TO BUY!! 160, 180, 190 degree? Also, do I need a new gasket for when I replace the thermostat?) - $4

- Goodyear Gatorback Serpentine Belt - $30 (choice between Goodyear and Dayco)

When replacing the serp. belt, how do I know how much tension to adjust the pulley to? The FSM calls for a new serp. belt to be between 180-200 ft lbs.

[CCJ]

I always used the finger method of testing my belt. If you have a tensioner, I guess tighten it to 190?