So I was working on my front brakes yesterday and the pads were really tight. So tight that I had to tap them out with a hammer and to get the new ones in do the same. Is this normal for the 4 piston calipers? or should the pad be able to slide on the pins relatively freely? It just doesn't seem right to me but I have never worked with anything but single piston calipers.

 

Did you try to "pry" the pads away from the rotor and that will force the piston inward? The pistons should move in easily, unless one or more are frozen in place. With the worn pads removed, each pistons should move into the bore as I stated earlier, quite easily. Usually the lower pistons will seize because of condensation in the bottom of the caliper.

 

no the pistons are moving fine and I pressed them back in. The problem is the pads fitting extremely snug and don't slide. I am trying to figure out if that is normal or a problem.

 

what kind of pads did you buy, sometimes the advance auto parts pads dont fit right. I used to work there, had a lot of returns.

 

they are hawk HPS pads.

the pins and slides were highly corroded and caked with crap. I had to sand them to get them back to a smooth shiny surface. I think that the original pads were still on the car.

 

you know buying new hardware is an option also and honestly that should have been replaced instead of sanding them to a like new finish. last I checked they were 15 bucks at the zone.

 

well the project is not done so the new hardware is still and option. I ran out of time yesterday. So the question still stands, should the pads be that tight or should they be able to slide freely?

 

I mean its ok if they are a tad tight but its also down to some common sense, if you have to beat them out with a hammer thats more than just a tad tight. Buy the hardware set and see how they fit after that.

 

The pads need to slide freely.
If necessary, file the sides down so they don't bind...sometimes the paint on the metal backplate (or the stamping itself) just needs some "deburring".
Also check the holes that the pins slot through, they may need some cleanup as well.

 

ok...I will get the hardware set and see if that frees it up. I just wanted to make sure that it was not right. I hope they don't have to order the damn set like everything else.

I didn't have to beat it out with a hammer but a little tapping was def necessary to get them free and to get the new ones in. But yeah they seemed abnormally tight to me that is why I was making sure that wasn't normal for this car.

Thanks for all the help

 

I usually open the bleed screws so I'm not forcing fluid back up to the master cyl as I push the pistons back in, and then I give the system a good bleed while I'm at it.

 

yeah they should move freely and I think it has to do with your hardware. try what clokker said and deburr the pads were they were stamped out. add new hardware and some grease and I cant imagine why they wont move nice and smooth

 

So I got it all finished up and working correctly. What was wrong was there was so much corrosion on the back of the metal slides and on the caliper that it was just too tight for the pad to fit correctly. I wish I took a pic of it, there was probably about 2-3mm of corrosion built up on each side. Thanks for everyones help...now it is on the fix the clutch.