Reed Bond

I bought my Jeep about 6 months ago and when I bought it, it had brand new brakes. Its been squealing lately and whenever I put pressure on the brakes the noise stops. It will make noise with out any pressure and the noise will stop with pressure. I replaced one of my calipers because I thought it could be sticking but that didn't fix it. Has anyone experienced this? Or know whats going on? Its a '98 XJ 4.0 btw.
Thanks!

spazzyfry123

Squeaking without any pressure whatsoever? As in you're going down the road and they are squealing? Or are they just squeaking with a little bit of pressure that goes away with actual braking force?

Reed Bond

squeaking with no pressure at all, just rolling down the road. If I tap the brakes with the slightest pressure it will go away, but as soon as I let off the brakes it comes back. It is not constantly making noise but every other day it happens.

jordan96xj

Squeaking with no pressure, that goes away with pressure is pretty normal. The pads very lightly contact the rotor (or drum) when the brake is not applied. What causes the squeak/squeal is a fine high-frequency vibration that is resonating through the pad and into the caliper and so on.

Typically this develops when the brakes were not sufficiently lubricated during servicing, or lubricated with a product that does not hold up. For example, some places will lubricate with whatever they have around (anti-seize, low temp grease, etc.) These dry up due to time and heat and things start squeaking.

Brake servicing usually calls for brake lube on all metal to metal contact parts. The lube acts as a damper and kills the high frequency vibration, which kills the squeal.

Typically with pads, the ears will be lubed, and the back plate where the caliper piston contacts the pad, and the back plate where the caliper contacts the pad are all lubed (lightly). On XJs it is also important to lube the knuckle slides that the pads slide on. This will reduce the chances of a pad sticking and will also reduce the damage that the pad does to the slide over time.

With drums, it is important to lube all of the pad contact points on the backing plate. These are usually slightly raised areas of metal, where the pad contacts and slides.

There are a few products available, but I prefer the permatex high-temp ceramic brake parts lubricant (it is purple, and comes in a plastic container with a brush lid for applying). It is not cheap, but it holds up well between brake jobs, and a bottle lasts a long time.

Brake parts lube can also be purchased in little packets at the checkout counter at most auto parts store. Takes about 2-3 packets to do the Jeep. Also, a new set of pads from a supplier like Wearever will typically come with a packet of brake parts lube in the box as well. And if used sparingly and carefully will be enough for the pads it came with. I use the disposable metal brushes to apply the lube sparingly, if you try to just squeeze it directly on the part from the packet, it is difficult to control and apply evenly, and you end up running short.

Reed Bond

Awesome thanks so much! Ill get it done soon.

jordan96xj

I recently helped a friend of the family who was convinced her brakes were done wrong and were about to fail. Turned out they were just squeaking and squealing. But it was driving her crazy (she was a bit OCD about it).

So I agreed to look into it. She had just had them done, and then had them rechecked by the same shop because of the noise. So I didn't know what to expect once I got in there. Turned out that the job seemed to have been done pretty properly, in that nothing was broken, or improperly positioned, or loose or anything. But what I did find is that they had lubed the parts with anti-seize (that permatex silver/nickle stuff). Its lubricating properties for brakes had failed in just a matter of weeks. It was dry and crumbly by the time I found it, and this was only 1-2 weeks after they did the job. I redid her brakes with normal brake lube, and they were all quiet again. And stayed that way.

JK253

Check your guide pin boots. They are often formed with a 'seam' in them and over time that seam will split, open up, and let moisture/road crud in. Eventually this will either wear the grease off the guide pins and/or cause corrosion on them which won't allow the caliper to slide back away from the rotor. Had this happen on a front and rear caliper so far (converted rear).

MonacaYankee

Check your steering knuckle for grooves from where the brake pads ride. Could be cheap pads too. I use wearever golds and never had a squealing issue in 8 years.