2001 Montana 3.4 127k with "crunching" front end


fritcr
02-14-2011, 02:56 PM
Our van has a "crunching" sound in the left front when you have to get on the brakes a bit. This only happens when it is cold and wet. It has been getting much worse. It does it almost everytime you hit the brakes now. It used to only do it to my wife....who likes to slam the brakes on right before she is about to hit someone lol. Anyway, it does it pretty much everytime you hit the brakes. Makes a loud crunching sound from the left front wheel. I have had the brakes off several times. They only have about 10k on them. I have turned the rotors then swapped them. Then bought a new one for the drivers side to no avail. Nothing is leaking that I can see. Van stops fine. I'm temped to replace the brake pads even though they do not need it. It sort of makes a creaking, crunching, squeaking sound. You can sort of "feel" it in the floor and steering too. I can't find anything loose at all. I have had this looked at 2 times by 2 different mechanics and they don't know either. I have to say it was when it was warmer and dry so the van did not do this nearly as bad. You had to really get on the brakes hard to make it do this. With the cold temps and melting snow everywhere it sounds like the front end is about to fall out.
Any ideas?
Rob

roadrunner2
02-14-2011, 08:38 PM
I don't think your problem is a brake one.

Have a tech take a real close look at the suspension components looking for dried up bushings and/or cracked assemblies.

The joints, etc will have to be pried at with a bar to check properly.

spike88
02-14-2011, 11:03 PM
If "crunching" sound and brakes look great, take an indepth look at its front Sway Bars. Ensure its end holes are still round, ensure its bolts (that go through these end holes) are still round and its Sway Bar connector rods look great as well. Many old GM nini-vans are getting "crunch sounds" from worn out sway bars. Especially when their chassis weight shifts - like when putting on the brakes.

For a visual of front sway bar, surf: http://images1.carpartsdiscount.com/auto/archive/pictures/44454/600/1/P/28C26A5/pontiac_montana_sway_bar_kit_front_oem_25861193.jp g

Hope this helps...

.

fritcr
02-15-2011, 08:11 AM
I'll look it over again but all of it "looked" ok. I have checked it several times and so has 2 other mechanics. Actually a mechanic and a tire shop.
I also have a Grand Prix and had the infamus sway bar that broke off and the vans look good.
The crunching seems to have something to do with the brakes because we live on a gravel road and bumps turns etc do not make this noise occur. Only when getting on the brakes hard. You can "feel" it in the steering wheel and on the floorboard of the van on the drivers side. It like the brakes are made of rubber and as it is almost stopped it is like taking rubber and screaching it on metal (ie. the rotor) it is very weird and I have never heard or felt anything like it. I have had and worked on a LOT of cars and this one is a first for me!
Rob

rkvons
02-15-2011, 12:51 PM
I'll look it over again but all of it "looked" ok. I have checked it several times and so has 2 other mechanics. Actually a mechanic and a tire shop.
I also have a Grand Prix and had the infamus sway bar that broke off and the vans look good.
The crunching seems to have something to do with the brakes because we live on a gravel road and bumps turns etc do not make this noise occur. Only when getting on the brakes hard. You can "feel" it in the steering wheel and on the floorboard of the van on the drivers side. It like the brakes are made of rubber and as it is almost stopped it is like taking rubber and screaching it on metal (ie. the rotor) it is very weird and I have never heard or felt anything like it. I have had and worked on a LOT of cars and this one is a first for me!
Rob
I bought a set of front rotors for my van and found out that the center hole was too big for my hub. It was off by 1/16 or 1/32" or something. What this ended up doing was constantly moving around as you applied the brakes. It was heard as a clunking, but you may be experiencing something similar. I had to remove them and take them back to the auto parts store and get the next more expensive brand, and that fixed it.

fritcr
02-15-2011, 04:14 PM
I swapped side with the orginal rotors then bought a new also. Nothing changed when messing with the rotors.

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