mtnbiker

Hello every one, I have been using this site as a guest for about 6 months and I've found only the best of advise/tips/technical knowledge.

Two weeks ago my 97 Cherokee overheated and I had to replace the head gasket and have the (very warped) head shaved. Put it all back together (using tips from all of you) with a new thermostat and water pump. Installed the belt in the correct direction.

I drove it 80 miles on the interstate from my dads shop home and no problems, runs great. This afternoon however I parked it coming home from work and as soon as I stopped the radiator cap popped and fluid went everywhere.

Aside from a new cap....anything that i missed that could be causing the coolant system to fail i.e. not circulate properly?

djb383

Hot coolant/pressure escaping to the bottle (via the rad cap) is normal (hot motor) as is coolant returning to the rad from the bottle as the motor cools. The bottle should never overflow nor should it run dry.

Demonoid369

I don't think that's what he's asking.. Sounds like its shooting out the cap, not into the over flow. Could check that small hose and see it its clogged.
What thermostat did you get?

djb383

Since the OP refered to a "new cap", as in he replaced the old cap because it was leaking, I presumed he understood that coolant escaping/leaking anywhere is not normal.

Demonoid369

He didnt say he replaced it, he said "aside from a new cap" meaning he needs a new one.

Op, check for clogs in the radiator, and what pump and t-stat did you get? The factory original t-stat are the best and sometimes the auto store t-stat can be a flop out of the box

Demonoid369

Actually never asked, what's the temp? Do you know if it was over heating or not? Maybe the coolant system wasn't burped well enough?

mtnbiker

I am assuming that i need a new cap. Ordering one tomorrow. The thermostat is just a auto parts store 9 dollar job.

the fluid is coming out of the radiator cap. I blew into the hose going from the cap to the bottle and the air went through just fine.

mtnbiker

I guess i don't know the temp either, i only have a dummy light. Which is what I attribute the warped head to.

I would like to know what the best aftermarket oil pressure/temp gauge/amp meter set up is so that i can be a real man and have gauges.

Demonoid369

Have you looked around for another late model in junk yards that have the full gauges? Mines a 97 also and had dummy lights but I found a full cluster gauge set at a junk yard. It'll help for you to know the temp while having the ability to also know your battery and oil pressure.

Have you checked to see if the lower radiator hose is flattening out? Did you check to make sure that the water pump is the right one with the right rotation?

mtnbiker

Will the radiator hose flatten if the flow of coolant isn't there?

I didn't think the question the water pump rotation, I just figured as long as the belt was installed correctly I was good. Does AC or no AC make a difference on the rotation of the water pump that I buy?

djb383

The only time the radiator hose(s) may flatten is if the valve in the rad cap, that allows coolant to return to the rad as the motor cools, is not functioning. If the valve in the rad cap does not open when cooling system internal pressure equals atmospheric pressure (as the motor cools), the hose(s) will collapse due to internal pressure being less than atmospheric pressure. The water pump is not a positive displacement pump and will not collapse a rad hose (from suction) that's in good condition. As soon as heat builds, the entire cooling system begins to pressurize.

Demonoid369

? The lower hose has the spring coil in it from what I've read and learned because there is a suction from the pump and if the hose doesn't have the spring, it will collapse allowing no coolant to go in to the engine. I've read the hose collapse when running(at temp) and at cold. We need more opinions/facts from others lol for the sake of this guy and me if I'm wrong lol

Op. from what's been told, older models and later model had different direction of belt placement and so the pump for early(?) rotated one way while later rotated the opposite. The I ly way you can tell is to look(can't remember where) on the pump and there should be a stamped circle with a R in it. That's the one you want.

djb383

OP.....even if the motor overheats and the rad cap releases pressure/coolant, pressure/coolant should only escape to the bottle, not outside of the cooling system onto the ground. If coolant was physically escaping to the outside of the cooling system (onto the ground), either the rad cap is bad, the neck of the rad is cracked/bad or both.

freegdr

x2^

mtnbiker

Replaced the radiator cap and the thermostat with a Mopar one and all seems to be working well. I think that it must have been the cap.

Good tip on the water pump being stamped with an 'R'

You know there are a ton of coolant issues on this forum. Is there a sticky or FAQ section on this? If not there really should be