Clutch fluid question

It also has a much lower viscosity at cold temperatures.

 

Good info https://www.remmenbrakes.com/brake-fluid-standards/

 

Here is the person to ask, @Jowett I believe you are working on a transmission swap, think I saw the thread around here someplace. Have you had your own transmission out? If so what type of lubricant is on the front throw out bearing guide? Is it possible that could be the issue?

 

Yes, it's out. I'll take a look at it.

 

Here's to not needing to adjust my hydraulic clutch linkage.. well except for getting rid of the "click" that one time.

 

Hmm, ok. I thought DOT4 LV was slightly lower, not half. 700 is actually better than DOT5.1 so I'll have to look into that more. TY

 

When stopped at an intersection the transmission should be in neutral with your left foot on the floor, not on the clutch pedal, and not in gear with the clutch pedal to the floor. And as I stated earlier, there is very quick engagement of the clutch, requiring the pedal to only be pressed a small way and not to the floor when taking off.

 

Clutch utilization technique isn't really the point of this thread.

 

Except proper clutch usage mitigates the problem.

 

Of prematurely wearing out your throw-out bearing because you're sitting at a red light with the clutch pedal in, yeah, but it doesn't mitigate the problem of the hydraulic clutch system not being able to handle the cold. I'm glad I don't live where that dude does because this would drive me apeshit for a significant amount of the year rather than mildly annoy me on a few very cold mornings.

I really wish I knew what the actual problem is. Like an orifice that was spec'ed with too small of an opening or something?

 

My point is that if you are in neutral at a stoplight, then when it turns green you only need to push the clutch pedal in a short distance and thus a slow returning clutch pedal travels less and returns sooner.

I usually put the transmission in neutral and use the clutch cancel button to start the engine, so pretty much the only time that I fully depress the clutch pedal to the floor is when engaging 4Lo.

 

I'm no transmission mechanic but only partially disengaging the clutch when selecting a gear seems to me like it would be tougher on the synchros. Then again, I don't have a chart that shows the clutch plate engagement pressure throughout the pedal's range of motion so you could be right that the clutch is fully disengaged only halfway through the pedal's travel.

Also, using the clutch cancel on a regular basis seems kind of odd to me. Pretty sure I'd have a tough time overriding my 20+ years of muscle memory to try to adopt that pattern. I park in neutral too so that wouldn't be a problem, but I know a lot of people religiously park in gear so that probably wouldn't work for them.

 

what is the approximate length of time you struggle with the symptom? and how badly do you struggle with it? the symptom being slow clutch pedal return when cold. most reports I've seen have a very short duration of it and it's no drama by those reports. i have this below say 30F, and like most reports it resolves within a few shifts.

 

Already answered:

It's not that it's a constant problem, like in @DingleTower 's case, it just one of several aspects of the truck that annoy me simply because the problem shouldn't exist in the first place. Like the fact that the tag lights blind the backup camera [fixed], the rear turn signals are red [fixed], the truck has a constant uplink to Toyota's data collection servers [fixed], the OEM shift knob is ugly and feels terrible [fixed], the only way to engage constant speed cruise control is to hold the button for 3 seconds [not fixed yet], AEB cannot be disabled permanently without Entune [not fixed yet], ... the list goes on.

 

Ha. Ok. Problem solved.

That's not how everyone drives.... If I'm sitting waiting to turn at a green light I'm not going to put the truck in neutral every time a car advances through.

Regardless.... The clutch sticks when it's cold. If it works for you, where you live, that's great. Not everyone will have the same experiences.

 

At those temps all kinds of stuff acts funny. But stick with dot3. Although I am still waiting for the ac drain to rust my frame 7 years and nothing must have got a good frame.

 

I've actually seen some inconsistent stories on that one. I've seen some people reporting frame rust issues, and others reporting that their AC just drains on the passenger side floorboard. In either case... What the hell, Toyota?

 

All Toyota vehicles in pre-production period going through the testing in extremally low temperatures at testing fields at Ivalo lake, Finland.
There is a 2 weeks detailed torturing (testing) procedure for prototypes and serial production units for quiet a few manufacturers.
Alternative testing ground is on the land of Oimyakon river valley, Russia. (-72c is a lowest recorded minimum).
So, they pass tests, components and assemblies designed to work spotless at least two weeks at temperatures lower than -35c.

OP, what you talking about?
Clutch at -37c (my experience) is a bit too hard to push?
Operate it gently, let fluid warm up to higher temps,
<Optional>
Go to gim, improve your left leg muscle ability.
Solved.

 

The push isn't the annoying part. I really don't even notice that. It's the fact that my foot leaves the pedal behind when I'm letting the clutch back out. So far I haven't had the extreme reaction that others have noted, like in extreme cold where the clutch sits on the floor for a few seconds and then snaps up and dumps the clutch in the middle of an intersection. Fortunately.

It's mostly just annoying, and it makes me wonder how the hell these trucks passed the testing you mentioned.
"Did the clutch pedal return?"
"Umm, well, eventually"
"PASS"

As I mention later in the thread, I've owned and driven several manuals in bitter cold and this is the first that behaves in this way so I've very surprised by the fact that most on this forum say "Yeah, that's normal. You get used to it."

 

Intersting..., yust wandering, cars you driving before were equipped with hydraulic clutch? If so, clutch was using separate circuit of hydraulics or the same with brakes?