Rear brake issue - can't get the caliper back on

[RangerMan]

Rear brake question - I searched and didn't see what I am asking...

Car is a 2002 Ford Mustang Premium V6 with ABS. I did the fronts today with little fanfare.

Got to the rears and it was a whole other story. The rear passenger caliper won't go back onto the caliper bracket. It seems to me that it is binding up; it is very hard to get it into proper position with the caliper bracket. I have the shop manual and it isn't very helpful, just says that installation if reverse of removal...and it came off just fine!

Any tips for getting the rear calipers back on? Do I just have to muscle it into place given that I have new pads with new springs on them that are pushing back on the caliper? Do I need to rotate the piston in farther, because I put it in as far as it would go (I have the special tool, and it is one that actually applies pressure as it rotates). Any input will be greatly appreciated! Can't wait to get her back on the road!

 

[Skymarshal]

The piston always needs to be farther into the caliper with new pads, since the new pads are obviously thicker than the worn ones. Look from the side and see if you have enough clearance. Also make sure one of the floating pins aren't binding. They're the ones sealed with rubber boots to keep them from corroding. Sometimes you need to adjust them before they'll let the caliper slide on.

 

[98CobraClone]

did you use a c-clamp to push the piston all the way back in? the piston should be far enough in to have the rubber seal squeezed out about 1/8"

 

[RangerMan]

I didn't use a C-clamp, I used a caliper retraction tool that squeezes and rotates the piston. I thought I put it in as far as I could get it to where the piston was recessed compared to the rubber seal. However, with new energy this morning I will try and compress the piston further. It sounds like that is the only way that it is binding up.

It didn't seem like the slider pins were binding. I did pull them out to inspect them, still super greased up, so I put them back in.

I'll post on the results in a few hours.

 

[RangerMan]

Here's the update.

The piston is compressed as far as it can go.

The problem isn't getting it to fit over the brake pads, there is something that is pushing back. I can't determine if it is the brake pad springs are too strong (seems like a weird problem, and I can easily compress the springs if I flip them over and press the pads down on the pavement.) Or the problem is that the parking brake cable is pushing back.

I can get the top caliper bolt back into place, but the bottom one won't go far enough to get into position. It is like something is really pushing it back pretty hard. I tried connecting the bottom one first and can't. I decided to try a little experiment. I disconnected the caliper support bracket from the axle/hub and tried to bolt the caliper to the support bracket a little further away. Sure enough I was able to bolt them together...so it doesn't look to be the pad springs. My guess is a too long parking brake cable and conduit. Not super too long, just long enough to prevent me from getting the caliper bolt into place.

My thought is to remove the parking brake retaining clip from the caliper so that the conduit can freely slide in the caliper. I don't think that would affect the parking brake operation because only the conduit could move freely, not the parking brake cable itself...that would still be anchored at the caliper and then up the car at the parking brake lever...make sense? What purpose does that retaining clip serve?

Question: If I remove the parking brake cable retaining clip from the caliper, and don't replace it, will I lose all functionality of my parking brake?

Replacing discs and rotors should never be this hard...I think Murphy is out to get me (this certainly isn't the first car I have ever done brakes on before). I am just about at the point of giving up and having it towed somewhere to get it finished up, but I have already invested a bit of money into the job (between parts and I needed some new tools) that I would prefer to just get it finished myself and be done with it...

 

[n0v8or]

It's not clear to me what is restricting the caliper. Are you having this problem on both sides, or have not attempted side 2 yet? If you temporarily put your old (worn) pads back, can you bolt the caliper on OK? If yes, I see two possible problems (both of which I have experienced before):
(1) Wrong pads, or installed wrong. Compare them carefully to the old ones.
(2) Pitting of the microfinished surface of the caliper piston or cylinder bore. This would prevent you from retracting the piston all the way. This happens when the piston seal is not kept lubricated and the pads are allowed to wear too much before replacement. The piston has to be well out of the bore to make up for the thin (worn) pads and becomes exposed to water, etc, leading to corrosion at that end. Solutions are to replace the calipers or grind some of the friction material off the new pads.

 

[FORCED2DV8]

This should be really simple, if the piston is pushed all the way in, and your pins are moving not seized into place, then the caliper should slide on fairly easy. If Not, Did the auto store give you the wrong Pads?? does the caliper go into place with no pads in it??? if so make sure your putting the corect pad on the corresponding side of the caliper, if you are, then you probably have the wrong parts. i.e. pads

 

[scottswan]

I replaced all rear pads and rotors on mine. You have to screw them wayy in while applying retracting pressure with a c-clamp. It's a pain but they do keep retracting all the way until they are even with the housing. I never messed with the parking brake cable, I left it attached and I left the parking brake off.

-Scott

 

[AP1995V6]

This is really a dumb question, but did you take the top off of your brake fluid resevoir? If not, it causes alot of pressure that makes it really difficult to screw the piston back in.