2015 Grand Caravan/Town & Country question

We rented a 2015 Town & Country for spring break, and just got back from a 4101-mile road trip late Friday. I'm a big fan of these vans, and this one was even better than the '13 one we rented 2-years ago. However, there was one weird thing I experienced but didn't find much on Google:

When descending the steep mountains of Colorado on I-70, as well as a few in Utah, when braking the van would develop a shudder in the front end almost like warped rotors. It would do it even with minimal pedal pressure, but when I braked harder it got BAD - like, "I think the front wheels are going to fall off" bad. The odd thing was even if I braked just as hard(or harder), but wasn't descending a steep hill, there was no vibration whatsoever.

My guess is this is a result of either, or a combination, of the following:

1.) The PCM is calibrated to provide engine-braking, but the steep descents were berkeleying with it's programming.

2.) Due to the angle/length of the descent, the ABS was kicking in - possibly to prevent brake fade? Although if true, this didn't feel like any ABS feedback I've experienced before.

Anyone have any ideas/knowledge what might have been going on?

How many miles on the van/brakes?

In reply to JohnRW1621:

It had 748-miles when we picked it up, and as I mentioned it never did it any other time than decending long steep hills - these were all labeled as 6% grades. However the vibration always started within 500' of first applying the brakes.

Did it feel like warped break rotors, as in pulsating pedal, or was it a shimmy you felt through the steering wheel/front end?

Good question. I worked at a Dodge dealer till recently and had not heard this one. On the old Trooper, if I was towing the race car in the mountains after 1-2 descents using brakes they would of course get hot and shudder like hell until they had a chance to cool off. Back to the flatlands, it wouldn't do it. No idea if that's what was happening with you.

My van did this and it turned out that the caliper wasn't attached to the car anymore. You may want to check that, as it's apparently easy to strip out the sliders.

That's probably not it though.

tuna55 wrote: My van did this and it turned out that the caliper wasn't attached to the car anymore. You may want to check that, as it's apparently easy to strip out the sliders. That's probably not it though.

Ours did it also, I just put it back together. Never thought it was anything but a fluke though!

chandlerGTi wrote:

tuna55 wrote: My van did this and it turned out that the caliper wasn't attached to the car anymore. You may want to check that, as it's apparently easy to strip out the sliders. That's probably not it though.

Ours did it also, I just put it back together. Never thought it was anything but a fluke though!

I had to replace my slider as the inner threading had stripped.

This was on the rear though.

Did it do it if you were braking on flat and level? If not, I would say the engine braking was freaking out the brakes and causing then to overheat.

We had a Lincoln Continental that while driving along on the interstate it would start shaking and wobbling. I would pull over, get out and walk around the car and nothing would appear amiss. Get back in and drive off and no problems. Happened a couple of times. Took it in to the dealer and described everything to them and said "its like the rotors are warping, but we driving along not putting on the brakes". Turns out it was a vacuum booster problem and the car was braking on its own. They replaced the booster and voila, all was well.

It felt just liked warped rotors. I've never heard of heat causing similar symptoms, but that makes sense.

This generation of Mopar minivans was infamous for having undersized brakes, at least on the lower-spec vans, and the symptoms are just as described. But I think 2012-up T&Cs should all have the heavy duty brake package. The 2-pot front brakes on mine are almost comically huge. But then again yours was a rental, so maybe rental-spec vehicles still get the cheaper 1-pot setup.

There's no disguising the fact that these things weigh the better part of 5,000 pounds nowadays, either.

petegossett wrote: It felt just liked warped rotors. I've never heard of heat causing similar symptoms, but that makes sense.

It's pretty common on 4runners.

In reply to Duke:

It definitely had some weird option combinations that(I hope) were the result of its rental-fleet life.

The 6-speed trans was great though, and we averaged just over 23mpg with about 1200lbs of people & stuff crammed into it, and that included all the mountains on I-70 all the way west, as well as the lesser peaks coming back on I-40, plus Las Vegas traffic, Grand Canyon & some other detours.

Duke wrote: This generation of Mopar minivans was infamous for having undersized brakes, at least on the lower-spec vans, and the symptoms are just as described. But I think 2012-up T&Cs should all have the heavy duty brake package. The 2-pot front brakes on mine are almost comically huge. But then again yours was a rental, so maybe rental-spec vehicles still get the cheaper 1-pot setup. There's no disguising the fact that these things weigh the better part of 5,000 pounds nowadays, either.

Does anyone know if these calipers/rotors are a bolt-on?

I don't know about whether they will bolt to a pre-2008 'van. But they will bolt to the 2008-up. The initial thought was that it would require the whole enchilada - front and rear calipers and rotors, plus master cylinder. However, it seems like people are successfully doing just the fronts, and not dying from it.

Duke wrote: I don't know about whether they will bolt to a pre-2008 'van. But they will bolt to the 2008-up. The initial thought was that it would require the whole enchilada - front and rear calipers and rotors, plus master cylinder. However, it seems like people are successfully doing just the fronts, and not dying from it.

The dual piston caliper is showing a lot less piston surface area than the single big one. I'd bet you'd have to switch the master and hence the rear calipers too to maintain the proper balance.

Boo.

I'll let you know. A friend of mine - who definitely knows the right way to do things - recently did the fronts-only job, to see if he thought it would be necessary to do the rest. I'll ask him what he thinks now that its been on the car a bit.

The popular upgrade on the 4runner is to use the Tundra rotors and calipers. You don't have to change the master. But it doesn't work if you have 15" tires like me. One more way I'm an inch too short.

Yeah, that's also true on the vans. 16" wheels won't fit over the calipers; you need 17s.

If the rental had a towing package then it could have been the load leveling and antisway systems fighting away.

I doubt its the same issue, but my 2000 Silverado 2500 did exactly the same thing. Long hills, gentle braking. Steering wheel would shake like crazy. New rotors fixed it.

They were smooth on level ground, normal braking. Must have been a heat build up thing I guess. But they had much more than 800 miles on them...

I found a lot of useful stuff about HD vs LD Grand Caravan brakes here .

Here's what my buddy said about his GC brake upgrade. He (so far) has just done the front rotors and calipers.

Duke's buddy said: It seems to work pretty well in ordinary driving. I suspect that I might still have a tiny bit of air in the system. I need to re-bleed it when I get a chance. Since the caliper piston volume is significantly greater on these new calipers, the pedal travel is a bit longer and the feel isn't as firm as before. I will probably swap in the correct, larger-bore master cylinder later. I have no idea how the ABS and stability control operation will be affected by this change. It rarely rains and never snows where we live, and we drive the van conservatively, so we rarely experience ABS or stability intervention. I would be more nervous about the swap if we drove it in rain, ice and snow. It all bolts up as long as you get the caliper with the adapter/slider. The Centric reman calipers came that way. I did have to hacksaw off a piece from the bottom of each dust shield, as it interfered with the caliper. If you buy new dust shields for a 2012-15 big brake van, you won't have to do this. Also: I would want to install new rear brake pads when swapping on the big brakes. Coincidentally, I replaced the rear pads on my van the week before I did the big brake swap. The new rear pads alone made a big difference in pedal height and feel.