when i hit my rear break there a real loud grinding noise.........i know the break pads cant be worn yet only had the quad a month
it a 400EX any idea what it could be

 

Is it just one wheel or both?

 

i cant even tell where it coming from but it doesnt seem to be coming from one of the wheeles seem to be more near the frame or chain .I cant really tell it just started last weekend at wayen forest.I thought rock or mud just got in the break pad clean it real good but today was still doing it.Only when i hit the rear breaks not at all on fronts

 

well if it is you'r chain, it is sliping off the
sprocket. you would haft to tightin the chain. now for the frame i don't think that could be. I mean how could it be,the frame?

 

Could be your chain. Tighten it to 1.5" freeplay. Try cleaning it. If it is especially bad, spray some contact cleaner on the chain and with a towel, rub it off real good. Then lube the chain. It is best to lube (and clean if neccessary) the chain after a ride, and leave it for a while to let the lube soak in. The noise could also be sand and grit on your rear sprocket.

 

i own a real good power washer.....so i powerwash my 400 after ever ride and lube the cain back up it real clean no sand or dirt on the disk breaks,but i did notice the chain seem to be lose but in a weird way the top of the cain isnt lose but the bottom part of the chain is..it look like it rubs the stock skid plate could that be the noise i hear when i hit the rear breaks.the chain hitting the skid hard

 

yup...... check out the skidplate
they are strong but not that strong

 

thanks for the post.found out what was worng.
dont ask me how i do not know but in a short amout of time 3 weeks of riding my rear break pad were worn down to the metal of the pads .i use my frount more then anyting so all i can guess is all the mud and dirt i have been stuck riding in, must of got into the break pads and ate them off

 

My rear pads are shot too. I have a pair of EBC to install but I am having trouble bending the lock tab back. I was holding the caliper with one had and trying to bend the tab back with a Leatherman. The Leatherman slipped off and I stabbed myself. When I was washing it off with water, I fainted. Afterwards, I said screw it and put off installing them. I will change them this weekend.