Surge when AC is on (1 Viewer)

[Poudre Hound]

Hey guys, I did do a few searches and only came up with one thread about surging of the engine when the AC is on. The other thread stated that it was noticeable at highway speeds. My truck has the "surge" for lack of a better word occur when I am sitting at a stoplight or other stop. I feel the compressor kick on and the rpms jump a little and the truck would move forward if I wasn't holding the brake down firmly. Anybody discuss this before or notice it? I thank you guys in advance. This site has been invaluable to me for the information I have discovered on my GX. -PH

 

[IAmDan]

I've definitely noticed this with my GX. But, at the end of the day, I've chocked it up to 140k miles worth of wear and tear. The AC cools well and the truck hasn't suffered any losses from it. Interested to see if anyone has a fix for this.

 

[GXO]

It is common to have the increased RPMs with AC engagement. It is an indication that your brakes need service if you can't hold the truck due to the surge associated with increased RPMs. I found I had the same issues when I had older pads, air in my brakes, etc. Since I replaced my pads, bled the brakes, no problems at all.

 

[Poudre Hound]

It is common to have the increased RPMs with AC engagement. It is an indication that your brakes need service if you can't hold the truck due to the surge associated with increased RPMs. I found I had the same issues when I had older pads, air in my brakes, etc. Since I replaced my pads, bled the brakes, no problems at all.

Hmm, I see. Well, I only have about 25% left on the pads. Just thought it was weird that I would notice the compressor coming on and off so obviously. Never noticed it in other vehicles I owned. However, this is my first automatic transmission vehicle. That could be part of it.

 

[FreeGX]

I noticed the same thing. Took off the old Therma-Quiet pads and replaced w EBC green stuff. Problem solved.

 

[little_joe]

Hmm, I see. Well, I only have about 25% left on the pads. Just thought it was weird that I would notice the compressor coming on and off so obviously. Never noticed it in other vehicles I owned. However, this is my first automatic transmission vehicle. That could be part of it.

I don't remember ever having a vehicle where I didn't experience this - rpm's have always kicked up. To Dan's point, though, I'd look into brakes; and maybe just press down a bit more firmly when stopped.

 

[Bluetribal]

I have noticed that this truck does tend to move on me at lights and I have to press down firmer. Guess I will be going with different pads than OEM first up will be rear pads since those are ready for replacement.
As for the RPM's I don't notice it to drastically and I drive all day every day with AC

 

[GXO]

I have had really good success with powerstop rotors and ceramic pads. Lots of stopping power. EBC pads are great, but man, the dust!

 

[Gx4sevend]

T4R.org had a thread about this a while ago. The consensus was replacing the front break lines with braided lines instead of the stock rubber ones. Apparently that fixed the issue as well.