Hi All, Probably a stupid question.

I drove around today, pulled over and water was peeing out of the truck. I was in a rush so didn't see where it was coming from, but it's 100% not a little drip or a leak.

Then when I got back in the car about 40 minutes later, drove for 5 minutes and she was in the red, so assuming all water had gone. Today I opened up the water coolant lid and it wasn't empty, it was had tthe correct levels based on the "Full" marking on the side.

Soo, is this because of pressure pushing water back into the coolant reservoir? If so how should I fill her up again? I want to fill her up, get her warm then see where it's squirting out.

I took the cap of the radiator and put 2ltrs in.

So what do I do now? My guess would be leaving the radiator cap off, fill up the reservoir, turn the engine on and keep filling the reservoir until water comes out the radiator?

Thanks

 

Try testing or better yet, replacing the radiator cap. You can also pressure test the system while it's cold by putting regulated air into the overflow hose that goes to the cap or using a hand tire pump. The best way, of course, is to use a cooling system pressure tester which is just a hand pump that fits onto the radiator cap flange. My tester uses 18 psi to test a 16 psi system so if it doesn't leak then, it's good. Don't go more that 2 psi over what the cap is rated for though.

Fill the radiator thru the cap until no air bubbles can be seen, then put the cap on. The reservoir is just an expansion tank to hold coolant until it cools down and gets sucked back in.

Please correct the mistake in your signature. You have a 98, not an 88.

 

So be sure to get a burping funnel, its super handy when doing any coolent job on an xj and only $20 on Amazon. I would suggest the water pump is going out, lucky its not insanely difficult and is inexpensive. However, it is recommended you flush your coolent system, replace your clutch fan, thermostat, lower and upper radiator hoses, tensioner pully and serpentine belt if you're going to replace your water pump soooooooo its up to you. It will take about 2 days to do all of it, however, it will cost less then $250, gaskets included, so not too bad on the wallet. Good luck

 

That's what I like about old jeeps. The parts are relatively inexpensive compared to modern cars and trucks. My buddy spent $275 for a front wheel bearing for his Exploder! Mainly because the ABS sensor is inside of it. That still doesn't explain it to me.