smiller

On a 2014 JK Rubicon with the 3.6L... when in 4-Low my brakes seem to require a lot of effort, much more then when on the street. When in 4WD braking isn't inadequate, just requires high pedal effort. Also it seems like if I simply switch back to 2WD on the trail 'normal' brake operation is restored. Is the computer making the change intentionally (for example to lessen the tendency for brakes to lock when off road, especially when descending a hill) in 4WD mode? I have also read that the 3.6 uses an vacuum pump when required, could it be offline? Still, that doesn't explain why operation is normal on-road (in fact normally the brakes are very strong.) When I notice the condition off-road I am usually crawling so I doubt manifold vacuum would be low and in need of any assist.

Is this intended operation?

Thanks

resharp001

I've never noticed anything like this on my 2013.

tjkamp

Doesn't sound normal to me either.

smiller

OK, thanks, I'll investigate further and see if I notice it under any particular conditions. Possibly it's just me in that maybe I was noticing it more on downslopes where the slope was what was actually causing the increased pedal effort. But even if I stabbed the brakes the pedal seemed somehow softer, as if the brake system was tuned to resist lockup. Not really a problem, just (seemingly) different than street operation. Could I actually have been into the ABS and not realized it? If so that's one smooth ABS system.

Since it's apparently not intended behavior I will pay particular attention on my next trip out to see if I can duplicate.

P.S. Sorry I accidentally posted this in the JL section, should be JK. Maybe a moderator can move.

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resharp001

@Bora Bora or @Rednroll , can you relocate this to the stock JK sub-forum.