muddpigg

howdy folks, been quite some time since i've posted on here - jeeps been running fine until just recently. actually it's still running fine, but i have found that i'm loosing coolant and can't seem to pinpoint the source of the leak. after jeep runs for a bit and begins to reach normal operating temp, i get fluid leaking from near the upper rad hose, but it doesn't seem to be the hose itself. more specifically the hard lines for the a/c become covered in fluid, but it can't be these lines, right? i mean the a/c and the engine coolant are separate systems/don't share the same fluids right??? i'm at the point of neglecting my jeep long enough that i need to flush the system anyway, but i need to track down and fix these leaks in the process. i know a pressure test is probably in order, but i don't have any fancy equipment like that. so any help/guidance/words of wisdom/personal experience are much appreciated.

additionally, after how many miles should the water pump be replaced?

ZINGGG

Yes the cooling system and the A/C are different systems with different fluids. Have you kept an eye on the coolant level underneath the radiator cap? If it has been dropping, you have a coolant leak that you need to pinpoint. Take a closer look down there and try and trace it. Is the upper radiator hose brittle at all? Or is the rubber still in good shape?

muddpigg

thanks for your response '96', yes the coolant level has been dropping under the rad cap. the upper hose is not brittle but it is more than three years old - been on there since i've owned it. the coolant is not coolant colored anymore! so i think this friday i'm going to take it to my buddy's place and replace a few items (hoses, t-stat and housing, water pump...) give it a flush and fresh coolant just so it's done, especially now that winter is almost upon us. any tips or pitfalls i should be aware of, i've never serviced a cooling system before? is the general method to pull the hoses and put water through the upper hose (and through the block) until it comes out the bottom hose clean? do i at least have that much right lol?

muddpigg

well, this morning before work i was able to do a little trouble shooting. it seems the leak in my system is coming from the seam (passenger side) of my rad. so, on the way to work on my old sportster a bit later i stopped in at advance auto since it's right on the way and they have in stock a replacement radiator for ~$109 and change. have done some searching here and have found that the part is an easy fit for some, and for others requires some modifications to various parts. so tomorrow will be interesting, to say the least, but it must be done and done tomorrow no matter what. will post back and let y'all know how it goes! wish me luck!!

ZINGGG

Good call on purchasing a replacement radiator rather than using a "stop leak" product like so many people do. Your cooling system will be very happy about that. And flushing the block is pretty straight forward. Once you drain the system (either by pulling the radiator petcock or the lower radiator hose off the radiator), pull off the thermostat cover and the water pump and stick a garden hose in the thermostat hole and wait for the water to be flowing clean through the water pump hole. While you're in there, and since winter is almost upon us, it would be a good idea to flush the heater core (do this both forwards and backwards), also using a garden hose.

muddpigg

one question regarding the heater core flush - the haynes manual claims the system holds 12.5 quarts. this total does include the heater core, correct? also since i'm already at it, should i be replacing the water pump too? odometer shows 158k, and to my knowledge it's never been done. i will also be replacing the t-stat, upper/lower hoses and the serpentine belt while i'm at it...

ZINGGG

Yes do the water pump too.

And yes that includes the heater core. My heater core is bypassed (because it leaks) and my cooling system takes roughly 2 gallons (8 quarts)

F1Addict

It's a good idea to change your water pump at the same time. Mine started leaking from the weep hole at around 113K. I got a replacement at NAPA for about $50 and replacement was straight forward (although it's probably a bit different on my '89).

The 12.5q coolant capacity includes the heater core.

muddpigg

thanks for your replies guys! got started today around 10:30 and finished around 1:30. everything was very straight forward and i didn't encounter any issues with fitting the advance auto radiator. in fact the only glitch was advance auto didn't have the upper rad hose in stock when i went to scoop up all my parts. poor planning on my part really, as they got one in from another store and it was waiting for me when i returned to dispose of my used coolant. hell, i only cut my finger once, it must be some kind of record for me! thanks again for bolstering my confidence. and sorry no pics, my wife would've killed me if she came home and found gunk all over the camera. she damned well might kill me anyway when she sees how much i spent!