hearing a kocking noise when i hit the brakes?

[MarketPlayer]

Everytime i slow down to go over speed bumps at work, i hear a knock only once and it sounds like it is in the front but could be the rear.  It is when i go from 25-0mph and it knocks at around 10-3mph.

When i am just rolling down the street next to a building i can hear a squeeking!  It is a constant squeel and i only notice it when i am going about 1-25mph.

Oh yeah...Another problem or just annoying noise the fastback is making is a weird swirling noise every once and a while when the a/c is on.  It kind of sounds like high pressure air escaping to a lower pressurized area?  I have no idea about this one, but when i have the blower on speed #4 it won't blow cold air, but when i turn the a/c off and back on to setting 1,2,3 it will blow regular cold air.  The condensor i think it is called makes a crazy loud noise when it comes on...sounding like a metal fan hitting wire, but it isn't the metal fan in front of the radiator, but the noise is defenately comming from the mechinism driven by the pulley that is furthest to the driver's side. If that made any sense at all.  I might be able to get a picture of it later on.

Thanks alot for any help that might surface,
-zac penn

[flipboi13]

It could be your wheel bearings, take them out and inspect them for scoring or chips.  (only if u know how)  Check your rotors and brakes to make sure there isn't any junk in there, it could be your brakes too.  Also check your CV joints to make sure the boot isn't torn on the rear axle.  If i think of anything else, i'll let you know.  But it would help if you could determine which wheel it is from.  Do a test drive and have someone riding shotgun listening for the noise.

[uiuc240]

I've got "parking lot knock"...I'm pretty sure it's a combination of worn outer tie rod ends, which then caused the wear and failure of the inner tie rod ends. &nbsp;I'm replacing all of the above next week. &nbsp;$$$ Oh well, I'm tired of the damn clunking. &nbsp;And if this is what you're experiencing, it only gets worse <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'>

Eric

[sykikchimp]

My car used to do that.. &nbsp;then I replaced brake pads, and my T/C rods, and the knock went away.. check to make sure you t/c rod bushings aren't blown, and that your brake pads aren't worn out.

As for the Cold AC thing, My old 90 model did the same thing. &nbsp;I think it has to do with pressure in the actual AC system. &nbsp;When I converted that car to R134 We were playing with the pressure in the system and found that if the pressure was too high the compressor would shut off when I turned it on 4.. &nbsp;but not on 1,2,3 .. and it would only blow cold on 4 at certain times with some pressures.. kinda weird. &nbsp;Never did get it to work completely though.

[MarketPlayer]

Thanks alot guys...Does anyone have a picture showing where the T/C rod, and the outer/inner tie rods are? &nbsp;I know where the CV boot is, so i can check that! &nbsp;My brakes are worn out, but even though i said i wasn't going to upgrade my braking system, i have decided to change to the Q45 brakes, so i will wait for that money to pile up before changing the pads. &nbsp;So is that mechanical device I was describing on the driver's side of the engine bay the AC Compressor? &nbsp;If it is then i want to get another one, b/c that squeeling noise it is making is driving me nuts! &nbsp;Thanks again for the help!
-zac

[240 2NR]

No CV joints in the front end. &nbsp;It's a rwd car.

The tie rod is what connects from the bellows on the steering rack to the tie rod end. &nbsp;The tie rod is attached to the knuckle and is a ball joint with a rubber boot. &nbsp;If you jack up your car and remove the wheel you should be able to tell what parts control the steering, thats where you'll find the tie rod and end. &nbsp;The TC rod connects between the lower control arm and the subframe. &nbsp;It's bolted to the LCA and has a 4" diameter bushing where it meets the subframe.

[silvia240]

as for wheel bearings... i have a 95 and the alignment guy told me that to replace the wheel bearings i would have to buy the whole hub also because nissan decided to press in the bearings into the hub. &nbsp;SO that cost me 250bucks just for the part and he charged me 160 for the labor. &nbsp;This is how you can check if your wheel bearing is bad. &nbsp;Jack up your car so your wheel is off the gound (obiviously) then with your hand pressin up again the bottom of the spring, turn your wheel. &nbsp;If you feel a tickin clickin feelin with or with out the sound, your bearings are bad. &nbsp;So the alignment guy seys...

[stevebsvs]

Im getting the same noise, except its when I brake hard...New pads, tie rod ends, got the T/C rod bushings from PDM (whiteline bushings) but the sound started right after installing the new T/C Rods with the whiteline bushings. Whyyy!???