Georgeeads

I have an 1989 Jeep Cherokee Pioneer, 2WD, 4.0. It does not have a fill port on the radiator you fill the cooling system through the coolant reservoir. The reservoir is cracked and blows coolant everywhere. I know i need to replace the reservoir. My question is Is that plastic reservoir going to hold the pressure? Or should I be looking for another problem? Thanks for your help. George

Firestorm500

Your Jeep has a closed cooling system. The plastic bottle degrades over time. It is designed to hold the pressure, but nothing lasts forever.

You can replace it with an aftermarket one made in China or a Chrysler one that might be made in China.

The aftermarket one is cheaper. My O'Reilly's had one on the shelf. Jeep dealer needed 3 days to get one here.

Some people will try to convince you to change over to the semi-closed cooling system. There is no reason to do that on your Jeep.

Georgeeads

Thank you Firestorm. I appreciate your help.


I changed the coolant reservoir and I test drove it. I went about 10 miles with no problems then suddenly the jeep over heated. Why did this happen? Thanks in advance for any advice.
George Eads

cruiser54

George, you need to get a different cap for that bottle. The standard replacements are junk. Go to Napa and get a 703-1396 cap.

Firestorm500

I'm not so sure it is a cap problem. Your new bottle should have came with a new cap if it is an aftermarket one. IIRC, my Jeep bottle didn't come with a cap. I had to buy it separately. You should always use a new cap. It is what actually holds the pressure.

Your overheating after 10 miles sounds like a head gasket problem. I hope not.

That may have been what split your original bottle.

freegdr

Did you top it off after thermostat opened ?

iweb

From experience get the Napa cap and you have to burp the system or it will heat up every time you drive. I parked mine with the back end up a steep hill and removed a plug toward the back and on top of the motor on driver side then filled bottle with coolant until it ran out hole and no air bubbles.

It still blew coolant out the bottle until I got the Napa cap, now it works fine.

freegdr

One other thing bottle does not get filled to top need to allow room for expansion...

Georgeeads

The new bottle did not come with a cap. I used the old one. It seems to be working properly but I will get a new one. I did refill the system after the thermostat opened. I will try raising the rear of the jeep and burping it. I have checked the oil and I find no evidence of coolant in the oil. I hope it is not the head gasket. Hopefully it is just an air bubble caught in system.
Thank you to everyone for your input it is truly appreciated.
George

freegdr

Whats it do sitting idleing ?

Georgeeads

I changed the water pump then I let sit and idle for 30 minutes. No problems. Temp was good. I got in and drove it about 10 miles and it over heated again. I'm hoping it is not a head gasket. Also the heat has stopped working. Could a clogged heater core cause over heating?
I appreciate every ones advice.
George Eads

SuperRA

Did you bleed the system? Maybe there's air in it. You should do the bleeding procedure like mentioned above by iweb.

Firestorm500

A clogged heater core will not cause overheating.

On my Renix, to burp the system, I just let it warm up to temp with the cap off the bottle. Then I run it at fast idle for 5 minutes to make sure all the bubbles work their way out. You can see the coolant churning in the bottle. When no more bubbles appear, you're good.

Your Jeep is doing what one of my 289 Mustangs did a long time ago. I found out it had a blown head gasket.

Georgeeads

I got the problem fixed. I ran the engine at an high idle for about 5 minutes and pushed the air out. I drove it for about 30 minutes in town and high way with no problems. Firestorm500's advice worked for me. Thank you everyone for your input.
George Eads