Ever since I got new tires mounted by Costco... the brake pedal has been very stiff when depressed to start the engine. Once engine starts however, it becomes easy to depress.

I'm only concerned because it wasn't like that before. I always had initial play on the brake pedal even if the car was parked for like a week. Is it possible that the costco mech banged my brakes or caused some minor leak on the brake line or booster during wheel installation?

Any expert help would be greatly appreciated.

 

Mine does the same thing, but I only bought it a little over a week ago and assumed it was normal.

 

Some of the brand new 2014 MDX's are also having this "hard brake pedal when starting after sitting overnight" problem.

Acura is trying to find a fix for the 2014 MDX right now.

 

Hmm so is this considered a serious issue that can cause brake failure? How can removing and installing wheels cause this? Is brake/vacuum line exposed to possible damage?

 

Well let me rephrase my above question... the "brake line" that goes into the brake calipers in my wheel wells... is that a vacuum line or brake fluid line? I'm trying to think... if the costco tech somehow damaged that brake line inside my wheel well... will that affect my vacuum pressure or would I have been leaking brake fluid?

 

They would be regular brake lines, vacuum lines are not strong enough for brakes.

 

I've noticed this too on my TL but it only seems to happen when the weather gets really cold.

 

This^

Happen to me today minus 31 Degree C brake was stiff to start the car, after the car warmed up it was fine.

 

Same for my '12 TL SH-AWD

 

Just noticed it on my 2012 TL w/Adv Pkg. Car had not been driven since Friday night but the temperature here in Round Rock, TX has been pretty warm. When I stepped on the brake to start the car it was pretty stiff and as soon as the engine started the brake pedal started to depress.
Never paid much attention before so I don't know if this is something new or it was there all along but I just never noticed it. Will keep an eye on this and see how often it occurs and under what circumstances.

 

My 2010 has started doing the same thing and it NEVER gets cold down here. As long as it lets me start the car ok I'm not going to get too concerned about it BUT I would like to know if someone finds the cause and a fix.

 

Sounds like a bad booster check valve? Find the service manual located in another thread and on page 19-22 there is the procedure for testing the brake booster and check valve.

 

The 2014 MDX has the same "hard brake pedal starting problem", dated back to last year.

Some dealerships had replaced the brake control check valve. It was good for one or two weeks, but then the problem resurfaced afterwards.

Acura has been hard at work on a fix for quite some time, so the permanently fix is highly likely to be more than simply replacing a few components here and there.

 

i experience this as well in cold weather but keep us updated if its a failure or normal

 

Same for me. My '13 TL has a stiff pedal when starting. I assumed this was normal.

 

My 11 TL started doing this a couple of weeks ago, took it in and they replaced the check valve. Fixed for now,gotta see how long it's gonna last.

 

Did they charge you for the repair?

 

No car is still under warranty.

 

when i called my dealer, they told me it was normal for my 2010. i started a thread on this years ago too, and a lotta ppl said it was normal
It happens to me regardless of temp. Usually if the car was off for a short period, it won't be there, it'll only happen when it's been sitting for a while. but a few times it was stiff after a fill up... so no more than 2-3 mins...

 

They are full of shit. There is no reason for a car with a normally functioning check valve to bleed down that fast. Overnight is no good, but a few minutes is completely unsatisfactory. Mine has stopped bleeding down since the check valve was replaced. I got in the car today at 11 this AM and the car was parked yesterday at 2 PM. Nice normal pedal after 21 hours is good by me!

 

Sounds like I need to drop the car off to the dealership and have them check the brake control check valve

 

I have a 2010 TL and my brake pedal does the same thing when it's cold out. Any luck with a permanent fix yet?

 

Mine stopped doing this on it's own. Possibly when i did a brake flush? But no parts were changed under the hood, and mine hasn't done it for years now.

 

I had my brake fluid flushed 1-2 years ago. I don’t think that has anything to do with it. Only happens when it’s cold and it’s more of a loss of vacuum feel on the pedal