Coolant Change Questions

40 to 332

I'm planning on completing a drain and fill of the coolant system this week. I have a 2013 in which the pressurized cap is on the reservoir tank and the second cap (non-pressurized) is located further back toward the engine. This set-up is foreign to me so I have a few questions for those of you who have changed the coolant. I understand the draining procedure as well as the emptying and filling of the reservoir tank … it's the filling of the rest of the system that is a bit confusing. The FSM wasn't especially helpful.

First, is it necessary to vacuum fill the system? There's a post indicating that without vacuum filling, you run the risk of air being trapped in the system which could cause over-heating. The post mentions the risk of a cracked head with no warning because of heat created by the trapped air (???). At the same time, there are other posts in which vacuum filling was not performed and everything turned out fine.

Second, regardless of the need for vacuum filling, I assume that the new coolant is introduced into the fill hole where the non-pressurized cap is located … correct? … and when filling you need to remove the air drain plug located near the top of the rad on the driver's side to allow air to escape while filling. Is this right?

Third, you add coolant up to the neck of the fill hole, and then turn the car on, allow things to heat up, and let the coolant cycle a couple of times. You then add coolant as needed to continue to bring it up to the neck of the fill hole. Then turn the car off and re-cap the fill hole. Then monitor the level of the coolant in the reservoir tank over the course of the next few days, and add as needed.

I've changed the coolant before on a number of different vehicles without issue. However, this system is a bit different and I just want to ensure that I have a good understanding of how to do things right. Thanks for your input!

Zthirty4NISMO

sub'd

__________________

B&W_Evader

Why??? Your car is only 4 years old. My Toyota Tacoma went 10 years and 120k miles before I changed the coolant in it. It's got over 260k now and still going strong.

__________________
|RIP|6spd-sport|OSG-LSD|XP8|RBF600|Eibach Sways|RE-71R|FI-34Row|Gen3-CAI|Yaw P.S.|

40 to 332

I recognize that the OEM "blue" coolant is rated as "long life" … and that it may last for several years. However, I've noticed that a few owners have performed a drain and fill and/or complete flush of the cooling system after 4-5 years … presumably to keep the coolant fresh and to replenish the additives. I'm just looking for input on how to re-fill the system after draining the old coolant since whether I elect to change the coolant now or 5 years from now, I'll still need to know. Unfortunately, the FSM isn't especially clear on the re-fill procedure since the diagram that's provided only shows the location of the pressurized cap on the reservoir tank, and does not show the location of the non-pressurized cap … so it's not clear where you add the new coolant. Also, the FSM doesn't indicate the need for vacuum filling, but an earlier post that I came across highly recommended it to prevent air locks. So it's a bit confusing. I'm just looking for advice from someone who has successfully done a drain and fill, with a list of the steps involved.

Jsolo

I did my first drain/fill after the car was just under 4 years old at around 18K miles. Took about 1 1/2 gals. I went with the nissan blue premix. Figured it's cheap insurance against future issues.

I did the vacuum fill method. The entire filling process took only a few minutes, and no hassles with having to get the system to operating temp, wait for thermostat to open, etc to 'burp' the system. Because this was my first time doing the vacuum fill method, I did let it warm up completely until the fans kicked on. Next time this step will be skipped. Monitored the level in the reservoir and radiator over the next few days/heat cycles. Never had to add any additional fluid. It's still at the same full mark today (almost 2 years later) as it was the day I did it.

I did buy a replacement drain petcock o-ring. Not really necessary. After 4 years there was minimal if any wear, I could of just reused the existing one. Be careful when tightening, it is plastic.

The MY 2012 only has one bleed screw and a traditional single pressure cap. I didn't touch the bleeder, and vacuum filling was done right at the radiator. According to this thread, the pressure cap is now on the expansion tank, while the radiator is just a cap. I suppose if I was vacuum filling one of these systems, I'd still do it at the radiator. Although, because this is now a sealed system, it really shouldn't matter.

__________________
G37S Sedan 6MT, Eibach swaybars, Invidia Exhaust, Weaker Clutch Pedal Spring

For sale links

barncobob

good insurance to do it sooner, not later....my thinking at 50K. Antifreeze wears out, turns acid and eats the radiator up from the inside..its cheap insurance ifn u are going to keep the car..