What the HELL am I doing wrong with my brakes?

[StageLeft]

After replacing rear rotors/pads two weeks ago and having some rubbing issue, at one point the left wheel wouldn't release properly and rubbed so bad in traffic the brake started to smoke. The calipers were rough anyway, so I put new ones on. Tonight, my right rear one, same fvcking problem.

Each time I'm cleaning and regreasing the pins. I can only guess I'm putting on too much grease. How much should be there, just a paper, super-thin amount? I didn't use much the first time, used a bit more this time. Should there barely be enough on the cleaned pins to cover them? I know that as the caliper presses in the pins move out. I'm thinking that perhaps they are staying "locked" out and not returning, due to grease directly in front of the pin.

TIA.

 

[StageLeft]

Could it also be improper (or lack thereof) of grease on the pads as they sit in the brackets?

 

[JJ650]

Gonna ask a dumb question here BUT:

Did you bleed the lines and check said lines (and resevoir) for water??

We got just a LITTLE bit of water in a line before and it cause the brake pads to wear on the rotor and smoked and got real damned hot.
It's an precaution and easy to check for.

 

[StageLeft]

They are completely bled. THey were still a bit soft and required a touch more bleeding, but it was fresh stuff. The time two weeks ago, there was no bleeding done and still the same thing. I really think either I'm not doing the pins right or I'm not greasing the pad. The horns on the ends of the pad that go in the bracket grooves I, somehow, forgot to grease. Both times. In the past I've never forgotten this. I think it must just be hitting some rust in that groove and not coming out easily.

 

[StageLeft]

Well I'm doing them for the third time. The bottom slider pins that have a rubber boot on them were almost seized. I've put a much, much smaller amount of lube on there and they're moving better, but still pretty stiff compared to the top ones. I lubed the pad as it slides *shrug*. Not terribly convinced with these pins. I'm using synthetic brake grease at the auto store counter. It says it's good for all parts including boots but also says it contains petrolleum distiliates. Maybe they're bloating the rubber boots on the pins, although if so I doubt they'd sell it at the counter.

 

[Jeff7181]

Petroleum shouldn't be used on rubber parts... you should be using a silicone based lubricant.

 

[Mister4x4]

W3rd. That's why hoses tend to give up sooner if there's an oil leak.

Did you bleed or flush? I ask because a friend of mine had a similar problem with his Mazda's brakes. Turns out, he'd topped off the master cylinder with power steering fluid when he grabbed the wrong (although very similar) bottle when he was in a hurry.

I'm not sayin'.... I'm just sayin'.

Hope you figure it out soon.

 

[woodie1]

I know you don't want to hear this but I bet you still have some air in the system. I had a bad situation like this and it took some time but I finally got the last air bleed out. Hope I'm wrong.

 

[StageLeft]

Originally posted by: woodie1
I know you don't want to hear this but I bet you still have some air in the system. I had a bad situation like this and it took some time but I finally got the last air bleed out. Hope I'm wrong.

How could air lead to a locked caliper, though? This really is the same thing that happened a couple of weeks ago when the system had remained closed and unbled.

Here is the lube I"m using. If I click the pDF link on the bottom it specifically says it's safe on all brake parts including rubbers. It does say on the packet it has petrolleum distillates, but I'm wondering if the rubber on my lower pin's sleeve (apparently many vehicles don't have this so it's not super common) is of a different rubber. I will hit up the stealership to see if they have an oem caliper kit with new pins. For all I know, the lower pins are supposed to be stiffer. Maybe so, but they were still basically locked up after a short time and that cannot be right.

Here, bottom pin, is the rubber sleeve thing. I still cannot find anybody online who knows what it's for.

 

[bruceb]

You can new caliper pins for the brakes. Sometimes reusing the old ones just will not work. Other causes may be "sticking caliper piston" in which case, replace the caliper. Also please check the brake rotor for lateral runout. If it is not true, it will rub on the brakes. Another item to check is the Wheel Bearing. It can be bad or too tight, which will cause the brakes to drag and get hot.

 

[Kntx]

Just take it to a shop already!

 

[Mr.IncrediblyBored]

Do you use the e-brake?

The e-brake cable in my Focus is too tight. Combine that with the cold weather (rust or possible water in the cable sleeve?) and the rear caliper doesn't release when I release the e-brake. So it drags while I drive and smarts to smoke. When I park in my garage where it's warmer, the cable frees up and releases the caliper.

 

[bruceb]

Knight makes a good point about the parking brake. I missed the section above where it said Right Rear. I would try his suggestion to check for easy movement of the parking brake cable and either lube it, adjust it or if needed replace it.

 

[StageLeft]

I've just put them together for the third time.

a) my hand brake is too tight
However,
b) I am really 90% sure the problem is the grease I was using. I am using some synethetic stuff from advance. It's safe for rubber parts, but my bottom calipers with the rubber sleeves on them are binding like fvcking mad. Two nights ago I put the brakes together but didn't quite finish. Came back out this morning, the damn things are completly stuck (well, almost; I did get them out). I think that although the grease maybe was "safe" for rubber, it was an extremely poor lubricant for it, so the rubber sleeves on the lower pins (aka bushings) were binding. I cleaned the hell out of them and put some silicone based lube on them and even now I can tell that they are moving like a knife through hot butter.

So, the handbrake after the caliper replacement was exacerbating this to some mild degree, but the main cause was, I think, these pins. If the caliper pulls the pin out while braking and it won't retract, it will cause the pad to drag. Then you end up with a red rotor like I had!

 

[programmer]

Its either the slides (need to be greased with silicone-based grease) or possibly the grease within the caliper piston-boot has been contaminated. The caliper might need a "rebuild" (basically just clean, regrease, and seal), or the easy way is replace the caliper.

 

[StageLeft]

Originally posted by: programmer
Its either the slides (need to be greased with silicone-based grease) or possibly the grease within the caliper piston-boot has been contaminated. The caliper might need a "rebuild" (basically just clean, regrease, and seal), or the easy way is replace the caliper.

Definitely not the caliper as they are both new now and the slides were crazy tight. I'll take one apart in a few days probably to confirm it's still moving nicely, but I'm really surprised that a rubber-safe grease could suck so much. The silicone really seemed to sort it out.