Rebuilding brake calipers

[jtehfreaks]

Hello, one of my front brake calipers decided to pretty much leak all of the fluid one day, so I bought a pair of rebuild kits to get the job of fixing them done myself. Disassembly was a piece of cake, but now that I've got the new seals on, I'm having trouble getting the caliper body onto the floating frame. The thing just doesn't want to get back into those grooves, anybody have experience doing this and have a few tips?

[minho78]

Shouldn't be that hard. Make sure you removed the old seal. Undo the bleeder screw so that the air leaves as you press the piston back. Make sure you wet the new seal with brake fluid or brake caliper assembly lube and you push the piston even or else it won't go back.
Good luck.

[HondaDustR]

Do you mean you can't get the "pot" back onto the frame from which you had to drive it off with a press/something big and heavy? If so, I used a small file lightly to clean the rust off of the slots and the corresponding tabs, placed the aligned frame and pot piston side up on some cardboard to protect it, and used a punch and big hammer to slowly drive the pot home, hitting each side a little at a time to keep it going straight until it bottoms out. I don't remember exactly what feature on the pot I put the punch on (near the slots), but there's a way to do it without damaging anything. Strategic use of a "bigger hammer"...

Good luck.

[djnolan]

Use a block of wood. Also use some synthetic caliper grease in the slots. And file off the rust where the follower spring contacts the caliper and grease it too. It should slide together with little force needed then.

[jtehfreaks]

Of course! Didn't even think about using grease, I managed to get the caliper body almost all the way onto the frame, about a 8th of an inch to go but it won't budge; I'll have to try greasing up and filing the slots tomorrow.

[minho78]

Originally Posted by jtehfreaks

Of course! Didn't even think about using grease, I managed to get the caliper body almost all the way onto the frame, about a 8th of an inch to go but it won't budge; I'll have to try greasing up and filing the slots tomorrow.

No grease. ONLY brake fluid or assembly lube. And it should go in by hand no need for force.

[HondaDustR]

Originally Posted by minho78

No grease. ONLY brake fluid or assembly lube. And it should go in by hand no need for force.

True for the internals of the cylinder and piston. Are we talking internal or external, because grease is ok external to the piston/cylinder.

[Skytrooper]

+1 on the grease and cleaning the grooves. Also the part of the frame that rides in the groove. There should be no paint or rust on the sliding parts and use a thin coat of grease on all sliding areas.

[minho78]

Originally Posted by HondaDustR

True for the internals of the cylinder and piston. Are we talking internal or external, because grease is ok external to the piston/cylinder.

For the sliding pins grease is fine.

[jtehfreaks]

I'm talking about externals; caliper frame to body, not piston to cylinder. I ought to get it done this afternoon, I want the old girl back on the road ASAP!

[andyshoun]

To put the piston onto the floating frame you just need to clean the parts and tap them back together lightly. I placed a small block of wood on the "tabs" of the piston and lightly hammered the piston back on the the floating frame.

When putting the floating frame and piston back onto the "support", I installed the spring first and lightly greased the sliding interface of frame and support. The small difficulty in putting the floating frame (with piston) back on the support is that the spring will try to twist and prevent the two parts from aligning correctly. Just apply enough twisting force to overcome the spring and was able to slide the two parts back together with just my hands on the workbench.



PS. these are pictures of disassembly. It cleaned up pretty well before reassembly.

[jtehfreaks]

That second pic reassures me actually, I was thinking the "tabs" on piston needed to be flush with the part of the floating frame they slide onto; looks like they don't need to be after all, just close.

Thanks for the suggestions guys! Looks like as soon as the weather heats up a little bit, I'm out to put the caliper back on and rebuild the driver side, though I'm tempted to just get them sandblasted and powdercoated before refitting them to the car.

[John_AZ]

jtehfreaks,

I just did mine and getting the 2 parts together is easy if you just look at the drivers side before you take it apart (unless its too late). The "spring" firm wire on the floating part has to be put in the 2 holes of the sliding part before you grasp it and slide it together. You will not be able to put the "spring" in the 2 mounting holes after the 2 parts are together.

Here is a DIY on caliper painting/rebuilding...Post 6 in link--BIG file takes a minute or so.

Rebuilt the Front Brakes - Nasty Grime Inside! (pics)

GL
John

[jtehfreaks]

Thanks for the link John, but I just got the caliper back on the car; the pads were a real pain though, I had to put them on the caliper before putting the caliper onto the car; I'm not sure but I'm almost thinking they might not be the pads for this car, they are pretty thick and the pad furthest from the piston will not even slide in or out, it fits in that notch the frame has on it.

Anywho, this fix is temporary as I plan on getting the big brake kit from rennbay in a few months.

[HondaDustR]

Originally Posted by jtehfreaks

Thanks for the link John, but I just got the caliper back on the car; the pads were a real pain though, I had to put them on the caliper before putting the caliper onto the car; I'm not sure but I'm almost thinking they might not be the pads for this car, they are pretty thick and the pad furthest from the piston will not even slide in or out, it fits in that notch the frame has on it.

Anywho, this fix is temporary as I plan on getting the big brake kit from rennbay in a few months.

That sounds normal. The further pad is supposed to fit into that notch, and yes, new pads can be a tight fit, especially EBC's. I don't see how anyone does a pad replacement on these without removing the caliper either.

[jtehfreaks]

Well, I just bled the front brakes and she brakes better than before, seems the car needed it anyway. Question, what size is the bleeder valve for the rear calipers? I don't have the correct size wrench for it, sucker is small.

[HondaDustR]

I believe it's 7mm.