The culprit of the odor and loss of power was the front right caliper/brake, it stuck and produced an acidic smell due to the burning brake pads, and of course the loss of power since the car was braking!

My mechanic said the caliper was damaged and replaced it with a re-manufactured one, just changed that and the hose... a couple of days later it stuck again... since he saw the rotor scratched and the pads worn out, he suggested just to replace the rotor and the pads since these weren't replaced when the caliper was... I also told him that the rear left brake was screetching and braking bad, so I wa suppose to come in this week to just replace that... but a day ago the front right stuck again, yup! after changing the caliper, the rotor and the brake pads! ... it gets really hot, a lot odor and smoke, once cooled off I am able to drive it, so drove it home and parked it till I get some better feedback or what to look for and see if I can get this fix... any hints as to what to look for? Thanks!

 

that seems really weird. I'll assume he greased the caliper slides, but it's a fair question. Honestly if the caliper is new (or reman) there's not really any way it should be sticking provided there is no air in the line.
I think it's fair to question his work and ask for him to look at it again no charge since this could be an install problem.
I'd ask him to regrease the sliders and also rebleed the system, since this should have been done. At least eliminate the easy stuff that way. Keep us updated

 

has he checked the hub? if the bearing in the hub are bad the pads will drag and eventually lock the caliper.

i just went threw the same problem on the from of my 00

 

Thank you guys! will definitely bring your comments on Saturday when I take the truck back to him. I've been also led to believe that there might be a prob with the master cylinder, another comment that I will bring to him besides the troubled truck! Thanks again for your help!

 

Nah, the master cylinder has two independent (opposite) channels (front right, rear left on one.. and vise-versa) if there was a locking problem (INCREDIBLY RARE in a master cylinder, as they usually fail to build pressure) it would involve both brakes on that channel.

I've had a locked rear caliper on my disco and it was related to worn out slides, shortly after a brake job which had moved the calipers/pads into a new position for the first time in many years - the dirty area of the slides cause it to bind / lock up. I actually noticed this by an awkward thumping vibration at high speeds shortly after getting on highway - minute later the axle was jumping practically. Got out and felt the wheel and yikes.. super hot!

You'd be surprised how many techs don't mess with greasing the slides.. for whatever reason the calipers on the DIIs seem unusually susceptible to slide lock-up.

 

Actually, the rear left was screeching and grinding pretty much, didn't notice it earlier cuz we were focused on the front right locking-burning-hot-lots-of-smoke-and-burning-smell issue... it wasn't after the front right rotor and pads were changed that we actually started to shift focus to the rear left's screeching and grinding pads/rotor, it doesn't seem to be locking, just wearing the hell out! reason why I was to returned to the shop, to replaced that rear left rotor and pads, but before returning there, the right front went kaput again, so just parked it 'till saturday comes in order to take it back to the shop... I did feel that sudden vibration on my way to the shop before they replaced the front right rotor and pads, caliper had been replaced a couple of days earlier... in fact, vibration appeared as I was about to get off the highway, I even thought that the my tyre was breaking apart... but realized it had to do with the brake issue since the tyre looked ok... so let it cooled off and off I went to the shop, the vibration resurfaced but went away pretty quick and I was able to finish the 12 miles to the shop!

 

Sounds very similar to what happened with me! I put VERY low miles on the DII so it had been ages since the brakes were changed - the slides were probably very dirty and dry, plus the old rubber boots etc.

You said they DID perform brake work before you started running in to these problems?

 

This is our Brake related history...

at 128,656 (Aug 2014) ... Had to flush the brake fluid due to mistakenly having poured some transmission fluid into the brake reservoir, so with some input from this forum I was suggested to flush it, refill it and bleed it; fortunately it wasn't much and was able to do it pretty quick...

at 133,592 (Jan 2015)... resurfaced both front rotors and replace pads. The rear ones had already been replaced sometime before the 128K miles...

at 134,030 (Mar 2015)... replaced front right caliper* and hose due to first wheel lock event (*remanufactured)... system was supposedly bleeded correctly

at 134,435 (Apr 2015)... replaced front right rotor and pads... system was supposedly bleeded correctly

That's pretty much it with my braking system, plus almost sure ABS not working, at least not during my tenure and 3-Amigos are lit! ;-}#