Just wondering if this is normal.

[imanabsolutezer]

In the morning, after cold nights, my brakes are shot. To get around this I have to pump them real hard 2-3 times and then it returns to normal. I mean it would make sense that they freeze because of the freezing sub-zero temperatures.

 

[Diagram14]

I dont know if its normal but mine does the same. Ive wondered about having water in my lines or just ice build up on the caliper sliders or something. Usually it takes me just a couple of pumps of the pedal to break through it but this morning I had to drive for almost 3 miles to get it to loosen up. Kinda scary...

 

[BigRogers]

When was the last time you had a brake flush?

 

[IanB]

I would say that is not normal. Check for brake fluid leaks under the truck, and try flushing/bleeding your brakes, but if that keeps happening and you can't find any leaks, I'd suspect the master cylinder needs replacing.

 

[Qyota]

If brake fluid checks out OK, replace the $25 check valve on the brake booster (follow the vacuum line from the intake manifold to the booster). It's a point of failure in cold temps. If it sticks shut, you'll have zero power assist. Get the valve and the new grommet for it.

 

[BTO]

If brake fluid checks out OK, replace the $25 check valve on the brake booster (follow the vacuum line from the intake manifold to the booster). It's a point of failure in cold temps. If it sticks shut, you'll have zero power assist. Get the valve and the new grommet for it.

Thanks Qyota for that bit of info. I'm going to replace ours. It's not as bad as the OP's but still not where I'd like them.

 

[Qyota]

No problem. This happened to me last winter, so I replaced it and haven't had the issue since. Master cylinders are not prone to failing, so it's unlikely to be the problem.

 

[quicksilvr]

100% agree with Qyota. I had a complete brake flush done last month, and this morning when it was -5 outside, my brakes did the same thing. Gotta be the check valve.

 

[fenrisx]

If brake fluid checks out OK, replace the $25 check valve on the brake booster (follow the vacuum line from the intake manifold to the booster). It's a point of failure in cold temps. If it sticks shut, you'll have zero power assist. Get the valve and the new grommet for it.

Thanks for the info.

My brakes have been doing this since last winter(only in the winter). I know mine isn't fluid or anything because I had it flushed last winter to try and solve the problem. I was getting ready to replace the master cylinder. You don't happen to have a part# do you?

 

[Qyota]

44730 is the valve (44730-60060)

44696 is the grommet (44480-24015) *this number may have changed*

This is for 96-00 4runners only, as the 01-02 models use a different type of assist.

 

[2runnersnyynyg]

Just did the same thing to one here at the dealer def the problem was exactly same.change that check and you'll be happy again to tailgate in the morning,jk AND THE NEW GROMMET #IS (90480-24015) THE VALVE ASSY # IS CORRECT/LIST ON THE VALVE $38.10 AND THE GROMMET IS $3.29 LIST( DEALER LIST PRICE)

 

[JohnsD90]

My clutch is heavy on cold mornings at startup, as is my steering and i am too, i think it has something to do with the thick fluid.

 

[imanabsolutezer]

Sounds good guys thanks a lot for the continued help for my newbness.