Shudder and "Jump" when A/C is cycling?

I've searched and cannot find a thread on it. I'll be at a stop light with A/C on, on the brakes of course, and the truck will lurch forward when the A/C compressor engages. 30 seconds later the A/C compressor turns off, no shudder when turning off, but another 20 seconds later and the truck actually lurches forward, moves forward 1/4 in while still on brakes? This happens way to often for me. Anyone have an explanation? Maybe I'm paranoid

 

Normal

 

(sounding to me like you have an automatic, if this is true....)i would think it would happen due to the RPM's jumping up slightly while the AC compressor engages. I wouldn't worry about it

 

You might feel A/C cycle but should not be any movement at all even 1/4" if you're on the brakes.

 

Normal.... this is a feature of our tacomas

 

That's what I was thinking but just wanted to get a better understanding.

I can understand that it's normal, I've heard that before, but shouldn't the brakes hold the truck in place?

 

lol, nice feature

 

Thats what Im saying, I just installed new pads, rotors, re machined drums, new shoes, all new hardware and a complete brake fluid flush, it should be holding better than ever now.

 

Your truck is really moving, find that hard to believe.

Mine revs a touch to compensate for the compressor kicking on and the truck ever so slightly give the sensation of lurching but it doesnt move.

 

seems normal, when my truck was new it was really strong and i thought a car hit me

 

Find it hard to believe? Have you been stealing my truck late at night and taking test drives? I dont think so... I intentionally leave extra room when coming to a stop because I know that it may lurch forward and I dont feel like tapping someone and raising insurance. 9 months out of the year it's hot as balls here, my A/C is running most of the time. If this is something brake related than I need to get it fixed, that's why I asked everyone for opinion on the lurch or shudder and how it affects them.

 

You're telling me I paid extra for this heartache?

 

I can definitely feel mine kick on, but ive never had the truck lurch forward. do you have/ will you get a video of this happening? when youre stopping normally does it takes excessive force to get the truck to stop, or does it feel normal? can you slam on the brakes and have the ABS kick in? if so, I wouldn't think it could have anything to do with the brakes at all. maybe the amount of pressure you apply while stopped? I sometimes like to feather the brakes to see if I can find that sweet spot between idle pushing me forward and the brakes holding me still (might be a weird thing to do, but who gives a damn).

 

Yey once I find my gopro i'll put it on and get a video. Sometimes it takes excessive force, sometimes it doesn't, it fluctuates. The truck is currently back at the shop because whole damn PS system went out, valve cover gaskets leaking, and tranny is getting a full flush and new gasket and filter installed, and of course a nail got in the passenger drum, caused a bur to appear on the newly machined drum and found out that's what was causing the clicking in the rear. This whole A/C thing is another issue. I only have 99k on it, but I push it hard so I expect extra expenses. And yes I do that feather thing too just to feel the breaking point of the tranny but the A/C thing is becoming more prominent after the new install of brakes.

 

ive noticed my trucks rpms rev up slightly when I'm stopped at a red light and I get a bit of a lurch forward too haha and that's without the a/c being on. it doesn't happen right away, but id say after sitting at idle for I don't know maybe 20seconds or so lol

 

Some times it causes it to lurch more than usual. Specially if you just have your foot lightly on the brake.

Perfectly normal.

 

Next time it happens look at your climate control, I bet you have the defroster on. Turn it off and drive around for a while, it will stop.

 

haven't noticed haha I don't remember noticing it in the summer when I don't have anything on. I very rarely use the a/c, much prefer driving with the windows down and when I have the heat on I always have it blowing on the windshield/feet. I hate the air blowing directly I my face. so you could be right, it honestly doesn't even bother me enough to think of trying to figure out what the culprit is.

 

The cause is the clutch fan engaging. It drove me nuts for weeks before I asked about it here too. I'm just passing along the information.

 

thanks for the info! makes sense haha when I first noticed it I was curious as to why it was happening but since then gotten use to it haha but now I know the answer if anyone one of my passengers ever notices, which is unlikely hahaha