Overly Touchy Brakes

[Rick3478]

I'm noticing the brakes seem pretty aggressive on my BigHorn. I hoped they might glaze up a bit as I start to get a few miles on it, but that doesn't seem to be happening. What happens is that when I start to apply the brakes, the truck's deceleration causes my foot's inertia to press harder on the pedal, which in turn applies more brake, etc. So to make a smooth stop, I have to start pressing on the pedal, but immediately begin to pull my foot back away. During most braking deceleration, I am actually pulling my foot back, trying to prevent it from braking harder. This is unnatural and fatiguing and makes braking more of a struggle than it should be.

I'm not that big of a guy, and this is just with my sneakers which are not very heavy. My steel toe work shoes are much worse.

Is it just me, or is anyone else noticing this?

I haven't dug into this yet, just starting to research it. Is there any adjustment on the booster, like can the amount of gain (boost) be reduced? It feels like that's where I would want the change, but maybe as an alternative, could a stiffer spring be made for the pedal return? Or do I just need to start hauling more ballast weight in the bed?

Any thoughts or ideas?

 

[31RamIt]

Do you have your heel on the floor? Because I've never heard of this. You may be able to adjust the booster though.

 

[Rick3478]

Yes, and I have the pedals as close to the floor as they will go. Wish they would go just a hair further, but it's tolerable.

 

[Richard320]

Do you have eTorque? Because it sounds like it starts regenerative braking too hard.

 

[Rick3478]

No, just hemi with MDS. I do get some engine braking when it downshifts, but I expect that and it's in addition to the brake aggressiveness.

 

[theblet]

How many miles you have? It’ll prob get better over time.

 

[vincentw56]

First complaint I've ever heard about brakes working too well.

You'll get use to it. Mine work really well too. Took a few to get use to it, but not bad now.

 

[Snekpete]

There are adjustments to various parameters that could affect braking in the Body Control Module, which is accessible via a tuner. I noticed some of these when I was setting the TPMS pressures. You could try messing with them yourself or look for someone/shop in your area that is knowledgeable with the RAM computers.

 

[Rick3478]

Following up with a bit of research I've done.

It seems that the gain of the vacuum booster is the product of two things.
1) the ratio of the areas of the vacuum diaphragm and the input valve.
2) the magnitude of vacuum (air pressure).
There's probably also a small internal spring to keep things happy, but it probably doesn't figure significantly.

#1 is fixed by design, so no opportunity to adjust there.
#2 can be changed with a regulator, and there are people who make such things, but it also affects the amount of maximum braking, so have to be careful and probably can't stray very far from atmospheric.

Changing the mechanical advantage of the brake pedal could help, but they've made the pivot base out of that horrible injection molded composite stuff, so that's going to be hard to work with.

Leaving me with adding a return spring to the brake pedal. I think I might have some stiff music wire around here somewhere to experiment with.

So now that I've over-thought it, I'll let that all settle in my mind awhile and wait for a pleasant sunny day to maybe poke at it a bit more. It's totally driveable, just a minor irritation really...

 

[Louhound88]

Would you have recently had your truck washed? Used any wheel cleaner and got some spray on the brakes? My brakes are super touchy and almost "sticky" feeling when I've accidentally oversprayed wheel cleaner onto my brakes. Takes some driving to get it off, until then I'll ease more into braking.

 

[Rick3478]

Would you have recently had your truck washed? Used any wheel cleaner and got some spray on the brakes? My brakes are super touchy and almost "sticky" feeling when I've accidentally oversprayed wheel cleaner onto my brakes. Takes some driving to get it off, until then I'll ease more into braking.

No, but I can't speak to what the dealer might have done when they replaced the Uconnect box. Hard to imagine they put more work into it than needed, tho'