Chace

I needed to replace the rotors and brake pads for my rear disk brakes, it's a 1980 280zx and I've been running into a problem. After I took out the pads and replaced the rotors, when I went to install the new brake pads they were too large to fit due to not being worn at all. I followed the Service Manual and turned the outer piston clockwise while prying on it to push it in a little and gained more room to insert the inner pad, but for the love of me I can't figure out how to get enough room to install the outer pad. I'm lost and hoping someone has had this problem before with a quick fix. I noticed the the piston seems to be able to move within the caliper and tried to bring it forward on the caliper to position it better but it won't budge.

I would really appreciate any help. Thanks a lot.

NismoPick

Welcome to ZDriver!

Did you at any point try to clamp the piston back in? The internal screw is somewhat delicate & can actually break if you put too much pressure on it.

Other than that, it's pretty straight forward. Is the piston all the way in so it's flush w/ the rest of the caliper face?

Chace

Thanks


Yeah I tried clamping it back in to create room which didn't make the thing budge, I also used a bar to try and apply pressure to move it back as well and nothing. No fluid came out of the bleeder when I tried these things, so not sure if that's good or bad.

I ended up turning it clockwise and applying pressure and it was flush with the caliper.


I've read the Factory Service Manual, and this is really my first shot at anything mechanical (I build and repair computers which I'm hoping would help me in this category) but the guy that was there with me so I didn't majorly destroy something has a general knowledge of cars and he was under the impression that the inner piston was giving us the problem. The manual talks about turning the outer piston to adjust but more than saying it exists doesn't talk about adjusting the inner.

FubarI33t

Well theres a reason for that. There is no inner. just a few springs, orings, ball barrings, couple of clips, a large hollow screw, the piston, and a rubber seal. about it.

NismoPick

Well, by clamping instead of turning you most likely destroyed the inner screw / stud that allows the piston to screw in. I myself even tried to clamp it back in when I was 16... and then had to replace the caliper (I didn't have a manual or ZDriver back then).

At this point I suggest removing the piston & inspecting the inner screw.

Chace

Alright really appreciate the help, I did turn it first but that never gave sufficient room to put in both the pads. It seems like I need to adjust where the piston sits on the caliper I see the grooves and it looks like it can move forward to position better, but I have no idea how to. I'll work on some pictures so I can explain what I mean better.

Chace

I have come to the conclusion that they gave me the wrong brake pads, or a heavy duty version of the brakes pads. Does this make sense to any of you about why the rear would fit but the front would come nowhere near?

NismoPick

Wrong pads in what way? Are the dimensions different? Do they not fit in the caliper? So you got the rears figured out?

If you got them in the caliper correctly, and they aren't fitting over the rotor, I would think they are the right ones... you just need to set the piston in farther.

BlueKitsune

The outer railing housing thingy on the rears also move so its not just your piston that moves, you need to make that rail slide out a little to fit your pads in. It move from both sides but the piston does all the work for both sides, if that makes sense

Chace

Yep this is it, I'm sorry I'm so retarded that I couldn't describe my problem correctly, the user in this thread has the exact same issue. I need to move the housing, so information on how to would be really helpful.

http://forums.hybridz.org/index.php?...0&#entry866830

So do I remove those springs that hold it in place and tap it with a hammer back or what? I never know how hard to push something on a car before the break point. I REALLY appreciate all the help, I'm a broke bitch and need this car as my only form of transportation so this is a huge help, Thanks guys.

Chace

I'd like to thank you guys for all your suggestions and help, really helped me narrow down my problem. I finally fixed it.

It ended up being the piston housing that sits inside the caliper that was seized up and wouldn't budge. I had to remove the springs holding it in place and spray the **** out of it with lubricant, give it about 20 minutes then bang it back with a hammer. Gave me enough room and works perfect now. Hopefully this helps anyone else who has this problem even though it was a very basic issue.