I did some maintenance(oil, filter, lube, coolant change) on the 4Runner and may've done something not so smart with my A/C. I was looking for the Heater Water Valve to bleed the coolant system per the Toyota Manual (still don't know where it's at).. Well, I saw a valve with a big "H" on it and cracked it open for a few seconds and immediately closed it. I later discovered that this was the High pressure refrigerent valve, that should never be opened and especially when the compressor is in use. What are the chances that I damaged anything? I didn't lose any coolant that I can tell because my AC is still ICE cold. Thoughts?

BTW, what the heck is a heater water valve? Why would you need to bleed the coolant system? The manual mentions that there are 3 coolant drain valves. I only found one! Where the heck are the other 2?

NOTE: It's probably just me, but I don't find the Factory Manual for the 4th Gen very helpful. They show some excellent schematics but don't cross reference to a legend or anything else. I guess these are geared toward the Professional grade level mechanics and not the shady tree guy like myself...

 

If you didn't let much refrigerant out, then it's probably fine. If it still blows nice and cold is the acid test.

The heater water valve is the valve that controls how much hot coolant flows through the heater core - it opens incrementally with the heater control on the dash. Some are cable operated and some are electric valves.

Why would you need to bleed the coolant system? Same reason you need to bleed anything - to let trapped air out. Many systems will trap air in the high points in the lines - the pump doesn't make near enough flow to push much air through the lines. Burping the air out will allow the coolant to flow better and make the heater etc work better. (On the extreme end: some big diesel engines for example - not properly burping the coolant hoses can cause the water not to flow and will burn up and engine in a few miles. Do not ask me how I know this...)

 

Worst case was you blew out some refrigerant and will need the system recharged. Best case, barely any came out and the system will still cool fine.

 

sound like you didn't do any damage to the cooling system. hope you didn't inhale any of that gas form the AC.

 

I would not tell any tree huggers you did what you did but you will more than likly be alright........Some engines have a normal bolt that plugs the bleed hole some have a zerk type fitting. I know the 3vz do not have anything and all you can realy do is let the engine run with the heater on for a while to just let the water flow through the system.....30 minutes should do it. bump the throttle up to about 2000 RPM every once in awhile to froce the water pump to trun fasters.....if you have a hearter for the rear you also have to trun that one on as well.

 

Thanks for the insight on bleeding the system. That makes sense.. However, I can't find the darn valve. I've got the factory manuals and it references the Water Valve, but doesn't show the location in any of the diagrams. I'm very disappointed with these manuals. I think their terrible for the amount of money that they cost.

 

I don't think any came out because I never heard or felt anything escaping. I cracked it think it was the freakin Heater valve, doh!

 

Nope, I didn't inhale!

 

Does anyone know the location of the Heater Water Valve on a 4th Gen? Surely, someone has changed/flushed coolant by now..

 

I would think you can just turn the heater all the way on.