brake job, new rotors, new calipers- on the front

[stevesquest]

Hey I'm a big dummy. I just did my first brake job. Replaced the rotors, calipers and pads on the front ( got my parts from Rock Auto and am fairly certain they are correct). It was rough but I got it back together. I have yet to bleed the brakes, but I needed to move the car out of the garage.

 

Obviously I got something wrong as the brakes are putting friction and rubbing against the pads and kinda scratching. I think I put it together the way I found it ( really isnt another way for stuff to go back together). Has anyone ever heard of this? The friction is pretty tight, like enough to slow me considerably when going down a slight incline.

 

Anyone have any idea what I may have done wrong? It would be great if you told me bleeding the brake would solve everything, but I dont think its gonna be that simple.

 

Before I moved the car I tried pumping the brake to get it back, after several pumps it built pressure, but then it was gone. ( I know you have to bleed before driving..cars isnt being driven at the moment and the back pads need doin so I thought I would wait till then)

[RWInspired]

Pads will scratch a little after coming to a stop untill you get a little speed to knock back the pistons. Bleed brakes, do a test drive. "If you can," get up to 15+ mph and use the e brake to come to a stop, jack up the front and spin the wheel to see how much drag there is.

[ucw458]

First, since you replaced the calipers all the air MUST be bled out of the system.

 

Second, NEVER get any grease, oil or brake fluid on the pad surface. It must be kept clean. The rotor must also be wiped clean with solvent before the caliper and pads go on. Grease, oil and brake fluid will contaminate the pads and make them grab. I know it sounds wrong but contaminated pads will grab the rotor much harder and may cause suspension or bushing damage. If only one side is contaminated then your strut rod bushings will wear out on that side and eventually fail. Trust me, that happened on one of my cars. If one side is contaminated the car will want to make a violent lane change every time you hit the brakes. If both sides are contaminated the brakes will be very "touchy" and will easily lock up the tires and skid.

 

Third, If your master cylinder hasn't already been changed now is the time to do it. I have had 5 of these cars and 4 of them showed up with bad master cylinders. If your master cylinder goes out you can lose ALL braking on the car. Check for leaking under the master and along the booster. If you feel any brake fluid there replace the master.

[Wolf87Conquest]

You will need to bleed the system for proper operation. Doing only a pad replacement...no bleed required. Front calipers are so easy to redo I don't know why they get replaced. I replace front calipers only when there is very bad wear/scoring in the piston bore. Otherwise...rebuild. The main part to replace in front calipers is the piston seal.

Now for the brake drag...as long as the pads are installed correctly..it will drag a little at first until the pads "seat". If your driveway is somewhat level and long enough...tap the throttle to move the car...then hit the brake to stop....go in reverse..stop the car. Move forward again..stop. The pads should be fairly well seated now. They will fully "seat" once they have gotten some heat in them from a couple miles of city type driving and have then cooled.

The pads and rotors MUST be clean...no contaminates such as dirt/grease/brake fluid. The pads get any brake fliud on them..they grab hold and usually do not come away from the rotor until you pull the caliper off and pull the pads with it. Then you need a new set of pads and the rotor cleaned with brake cleaner or parts wash solution and a scrub with a Scotch Brite type of pad. General dirt or grease can be cleaned up with brake cleaner..a scrub with a Scotch Brite type of pad for grease...and reinstalled.

What condition is the caliper mount bolts? Smooth without any deep scoring/pitting should be fine. Did you coat the mount bolts with a little grease...the calipers slide on these bolts. The front brakes are very similar to the Kelsey-Hayes brakes used on Chrysler products for many years.

What condition is the brake fluid? Dark fluid could contain debris that may have blocked the line, not allowing pressure on the piston to be relieved. Needs replaced.

The way the parking brake on rear calipers work causes lock up problems. If the rubber boot on the rear calipers is cracked/split or has any holes in it...chances are the mechanisim under the boot is locked up due to moisture/rust. These calipers are such a pain to take apart and rebuild correctly...I'd replace these calipers and save the trouble and headaches just from a cracked/split/holed boot. The mechanisim under the boot pushes the caliper piston onto the pads to activate the parking brake function. Can cause the piston to "stick" and not allow it to retract.

[The Rabbit1]

also remember that rotors are packaged in a film of oil to prevent rust, this is why you need to clean off with brake cleaner before installing.

 

if pads are good, and tires are hard to spin when off the ground it sounds like your calipers are sticking and not retracting. If you didn't change the brake lines I'd say they are bad and need replacing. I did the ones on my car when I got the car. Every last one of the 8 of them was dry rotted and cracked up bad.

Edited December 8, 2010 by The Rabbit1

[Metric-man]

Some times if you buy "loaded calipers" (calipers with pads and grease already installed) from a warehouse supplier,

(and since our vehicles are over 20+ years old) the calipers are more than likely going to be rebuilt.

 

The supplier doesn't always check to see if the calipers are properly greased.

pages 5-57 and 5-51 of the FSM http://www.starquestgarage.com/manuals/service/conquest/1988/88_conquest_service_nav.html

and if they were specified as being "loaded" and they are not pre greased ,as instructed in the above link .

A tub of caliper grease should be included in the purchase price.

 

(If you haven't already check...for and grease)

The front caliper floating pins and,

the rear caliper pins, inside the caliper body on the spring washers under the spindle and,

under the parking brake lever cap.

 

Chances are if you don't have grease under the lever cap the rest of the caliper (spring washers) were left dry also.

 

You'll need to grease them but the rears are tricky to reassemble for a first timer without the proper tool.

 

You'll need to re adjust your parking brake cable also.

 

But be careful like ucw mentioned about getting the grease on the friction surfaces.

 

Also inspect and replace your brake lines, even small cracks in the rubber hose can let air in,

but show no signs of leaking fluid out.

 

(sorry I see you did the fronts only)

Edited December 11, 2010 by starion_cult