After refilling the system, the Sequoia (which seemed to hold vac fine when I pressure tested it) is still losing refrigerant. After extensive UV light searching, I've located the leak definitely to the connector where the high pressure line runs into the rear A/C unit (at the back of the car). Probably a bad o-ring there since those are apparently pretty common.
Anyhow, my real question is this (since I don't really want to drain the system immediately to deal with this, since it still blows fairly cold) is this: When the rear A/C is turned off (via the front HVAC controls), is there a valve in the front A/C that closes the coolant lines going to the rear if only the rear A/C is on? I'm only asking because, for the short term, if that is the case I'd be ok with just not using the rear A/C if it meant I wouldn't lose any coolant just using the front/main system.
Or is it an "open" system. I can't find a good schematic in the FSM for the car....
btw, actually it may be a freon return line, since it gets hot when the A/C is on.
I don't have any toyota SUV experience, but all of the vans, minivans and ambulances I have done A/C work on were one big refrigerant circuit with no valves between the front and rear units.
psychic_mechanic wrote:
I don't have any toyota SUV experience, but all of the vans, minivans and ambulances I have done A/C work on were one big refrigerant circuit with no valves between the front and rear units.
This is my experience with my Sienna.
yeah, that's what I assumed. Thought maybe I'd get lucky since the Sequoia is also available without the rear A/C. Guess I have to drain the system, put in a 50cent o-ring, and then drop another hundred bucks for the 9lbs of coolant this monster takes, lol...
irish44j wrote:
yeah, that's what I assumed. Thought maybe I'd get lucky since the Sequoia is also available without the rear A/C. Guess I have to drain the system, put in a 50cent o-ring, and then drop another hundred bucks for the 9lbs of coolant this monster takes, lol...
I just keep topping mine off. I have multiple tiny leaks at the rear A/C... But it's been 1.5 years and it hasn't drained out enough yet..
Yeah, I just filled mine fresh a month ago, and wife is already complaining it doesn't get cold enough (though it seems cold to me). Viewglass is bubbly. With a system this size I'll just bite the bullet and drain it. The leak is at the junction where the line attaches to the rear unit, so I think it's just a bad o-ring, which are said to be a common failure on Sequoias/Tundras. Guess I'll find out soon enough.
old_
Reader
6/6/14 10:03 p.m.
Here's a tip... If you are going to drain the system, open every joint and put blue nylog on the threads and o-rings. You shouldn't have any leaks after that.
Nylog is well known in the HVAC industry, it's some amazing stuff.
http://www.refrigtech.com/Product/Sealants/Nylog/nylog_blue.html
http://www.trutechtools.com/Nylog-Blue_p_1987.html
yep, the ones under the hood already have it on there from the first time I did it 
But thanks for the validation!
