Hi all!

Happy owner of a 1995 D1 for the past year and change. So AC was serviced just yesterday. Hasn't worked since I've owned it, the hoses need to be replaced because they were leaking. AC worked great driving it home today. Stopped at ACE, and walking back to the car, I saw coolant leaking out all over the pavement. Popped the hood, and the expansion tank is filled to the brim, leaking out the cap. I cannot find a leak anywhere. I was able to drive home, did not notice any steaming of dripping of fluid on the drive home. As soon as i stopped outside the house by the storm drain...to be on the safe side....the fluid continued to boil over and the cap eventually popped off, and all the fluid spewed out of the reservoir, i doubt their is any left in the system. I've reached out to the AC guy to see if he might of tampered with anything. Side note, the small tube that goes to the TOP of the radiator to the expansion tank was bubbling profusely when I inspected it in the ACE parking lot. 2nd side note, T-state and radiator replaced 3 months ago, no issues.

Thanks guys

 

Could be either a tiny crack in the expansion tank and or the expansion cap not having a proper seal to hold pressure.

 

Maybe check your fan clutch. It is needed to engage the fan stronger at low speeds around town. Can you measure the coolant temperature?

 

sounds more likely that the electric fans are not working. They should be on full blast with the AC on. (the ones in front of the radiator)

 

A/C creates a ton of heat in the engine bay and is often the trigger of an overheating episode. Some choose to basically abandon A/C.

To keep the truck cool with the A/C on, particularly at idle, you MUST have the electric fans be in good working order. The main engine fan is of limited effect at idle.

Other things that might come to light when the system is stress are old hoses, partially clogged radiator, non-sealing reservoir cap, stuck thermostat, and a reservoir that splits itself in half under the built up pressure in the cooling system.

 

Thanks for all the responses guys, sorry it took so long to respond. So I'm starting to think the along the lines of what you were all saying in regards to the ac producing an exorbitant amount of heat, and thus pressure. I was able to fill the system, bleed it, and have get it back to the garage, it appears to be holding pressure, and coolant at idle with AC on. Have yet to drive it though...

Toran = expansion thank has no signs of cracks, like I said, just replaced earlier this year, however i think the build up of pressure when i stopped managed to crack the cap, I've order a new one.

JohnZo = At operating temp, I could NOT stop the fan clutch with a hard piece of cardboard, so I think it's safe to say it was doing its job. I don't unfortunately, its a 95 so it has no obd2, I've seen some people talk about a digital temp gauge that that can be plugged into the thermostat housing sensor port, but haven't found a write up on it yet.

jimvw57 = The AC fans on the other hand were another story. The passenger side ac fan was working, driver side not. Even after hitting operating temp it would not kick on, I removed the front grill to get at the connection, they appear to be plugged in (so hard to get at!). Apart from a burned out motor, is there any other reason why one would work but not the other?

Walt NYC = I live in AZ, so it is a MUST. And on top of the temp outside, the amount of heat that spills into the cabin from the engine is just fuel on the fire. Hoses are intact, but closer inspection of the water pump, there is some crud build up and signs of drippage, but nothing that screams massive leak. T-stat is brand new. I agree, I'm thinking that that ac fan is my culprit hopefully.


So plan of attack:
- I plan on troubleshooting the non working ac fan (suggestions?), also noticed as soon as the engine is shut off, they shut off as well, i thought they were supposed to shutoff after a certain amount of time after engine is turned off?
- I'm looking into a combustion leak tester, found this one, any other suggestions? . I have a aftermarket clear expansion tank, coolant is green on the stop, brown rust tinge toward the bottom of the tank, assuming its rust. Just want to make sure that it's not something else.
- I'd like to get a temp gauge wired in, any write ups you know of that would guide me through it?
Thanks again for the help, please run anything else by me that pops into your heads. I've driven a Jeep XJ with the indestructable 4.0 i6 for the past 15 years, which i love dearly. But, this is new territory LOL.

 

Keep us posted.
After replacing my entire cooling system in the end it was a pin size hole in the cooling expansion tank. As long as it ran it would not leak, though after driving it and turning it off it would overflow through the the expansion cap.

 

Well I managed to solder a new motor into one of my condenser fans...unfortunately it still managed to overheat today during an emissions test haha! Given, it's pre obd2 so they have to run it through it's paces. it managed to boil over again. drove home with the ac off just fine. I'm think possibly a water pump malfunction. that's the only part of the coolant system that has never been replaced. I'll give that a try, and if that doesn't solve it, i'll take it back to the AC guy i used to see if he can figure out if my compressor or something in the ac system are overloading the system. Plus, i managed to not pass emissions LOL. it was a rough day...

 

Sorry to hear you are having it so bad. I had trouble getting a quality pressure cap for my aftermarket expansion tank. Found a genuine cap at British Parts of Utah. If it is not holding pressure, that could cause boiling, especially if the coolant mixture is weak. To measure the temperature, I use a thermocouple wedged under the hose at the t-stat housing. A non-contact IR type thermometer could also work, and not expensive, and useful around the house. If it is boiling over and not very hot, then you might have exhaust gasses in the system, and that would be the worst case scenario.

 

Go here and read the top portion about roverguage. Software and Gadgets to remap the Lucas 14CUX the same cable with usb C to usb adapter can be used with the Android phone running RS-RV8.

I've used this to read temps on my 95 disco. RoverGuage can also read the codes stored, and reset them as well.