hard brake pedal

[bluecrewnuke]

Lately, on the first startup of the day, the brake pedal is rock hard. The truck starts just fine, and there seems to be no problem with the operation of the brakes. I just wondered whether this might be the symptom of something sinister.

 

[Neurobit]

Lately, on the first startup of the day, the brake pedal is rock hard. The truck starts just fine, and there seems to be no problem with the operation of the brakes. I just wondered whether this might be the symptom of something sinister.

Def not normal. I'd have the dealer take a look since it involves the one thing that makes your truck stop

 

[Mr. Hindsight]

Lately, on the first startup of the day, the brake pedal is rock hard. The truck starts just fine, and there seems to be no problem with the operation of the brakes. I just wondered whether this might be the symptom of something sinister.

I had this same issue on my ‘17 Charger. The dealer said they couldn’t find anything wrong. Definitely didn’t seem right to me. The brakes always seemed to work fine tho .

 

[Scram1500]

Does the pedal start to sink right after you start the truck?

 

[bluecrewnuke]

Yes, the pedal feel returns to normal right after startup.

 

[Scram1500]

There is a tiny air leak in the diaphragm of the brake booster and it is losing vacuum overnight

 

[broman66]

Funny that I saw this today. Yesterday I had this happen and thought for a second that it was odd. I discounted it until I read this post.
I will keep an eye on it as it only happened once so far.

 

[scottmoyer]

My 2015 Charger Scat Pack had this exact issue. The brakes worked fine, but the first start pedal pressure was hard.

 

[Richard320]

The power booster is bad or the check valve in the vacuum line is bad. Either way, you're losing vacuum. Unless there's a TSB pointing at the booster, they'll likely start with the check valve because it's cheaper.

 

[SpeedyV]

Lately, on the first startup of the day, the brake pedal is rock hard. The truck starts just fine, and there seems to be no problem with the operation of the brakes. I just wondered whether this might be the symptom of something sinister.

Stiff, yes. "Rock hard", no. I remember this being a discussion in the very early days of this forum...so it seems to be "a thing" with these trucks. The pedal has always been a bit stiff on mine when cold (2+ years), but the brakes are great and the truck starts fine (as you point out).