Hey friends - I'm replacing my rear calipers + brake lines with stainless steel lines + pads. Calipers and pads are OEM Nissin. Fronts were very easy but the rear caliper piston is giving me a lot of trouble.

I have the special tool for the recessed X pattern on the rear caliper piston head but no matter how far I screw in the piston head, it doesn't allow me enough clearance to slide the caliper over the pad. It ends up catching onto the metal tab on the back of the pad.

When compressing the piston, are you not only supposed to twist it in but also apply a lot of pressure on the head to get it to fully compress? When I just twist it I can get enough clearance to slide the tab through one of the piston head recesses but it eventually catches on the recess and doesn't fully slide in.

Any help on how to do this properly? Should I be heavily pressing into the piston head along with the twist to get fully clearance for the pad/metal tab?

Reference: https://howtune.com/articles/308-cha...iston%20groove

Thanks!

 

You only twist the Piston in. Pushing does not work, becaus the piston rides on the Handbrake rod, wich is threaded.
Have you opend the Brake Master Cylinder reservoir cup? If you have added break fuid at some point, it could be that the level is to high and you therefore can not push the piston farther back in.

And, while it is almost impossible as you use Nissin parts, but Nevertheless: take calipers and meassure the nub / pin at the back of the brake pads and compare the old ones with the new ones. i once faced the same problem, the new brake pads didnt fit. The messurment showed that nub of the new ones differd. A little gently german swear and the use of a bench grinder and a file and some minutes later they magicaly fitted.

 

Yeah, I'd be 100% sure those are the correct pads, before damaging anything.

 

also make sure you have the little tab/tit on the back of the inboard pad aligned with the slot in the piston. The piston will need to be turned so one of the slots in the X is perpendicular to the pad so when you slide the caliper over the pads the slot slides over that little nub. is hat the metal tab you are speaking of?

I also highly recommend a tool like the below for brake work. The little cube things are junk that should be thrown as hard and far as possible It also works great for the fronts and can be used on many different vehicles. But it helps remove the clumsiness of dealing with the screw in rear pistons.

 

Ya I ordered OEM from hondapartsnow. Here's the direct link: https://www.hondapartsnow.com/genuin...206MT&filter=()

I confirmed they fit according to the "does it fit my car" thing.

I just spoke to a Honda mechanic near me and he said the tolerance/clearance level of a new brake pad in the s2k should be tight. As in, the bedding process for a sports car differs immensely, especially a stock, track ready S2000, so the pads will be tight to ensure it's as performance oriented as possible(?). And that I should just put the calipers on, even if they're tight (tight, not locked on the rotor) and drive 35 mph and slam on the brakes.

 

Yep, it's aligned and yes, that's the tab I'm speaking of. I can get the caliper to clamp over the pads but it's tight.

Appreciate it, that's actually the exact kit I have

 

I've not opened the cup but I'll do that. I do have the bleeder valve opened all the way.

The e-brake is not engaged but it is connected to the spring. Not sure if that should be fully removed to help.

I'll take some measurements on the nubs, thank you!

 

They will fit snug but should not be super tight like that. Does not require disconnecting ebrake and really should not require opening a bleeder at all. I swap pads a lot with track days and I never touch the bleeder or the ebrake for a pad change. Maybe make sure the ebrake is not partially engaged when it is fully down?

Make sure you do have the correct rotors as well.

 

Damn, I'm at a loss then if the e-brake doesn't need to be removed. These are the calipers I got as well, OEM with 71k miles: https://www.ebay.com/itm/397129129398

 

Check the adjustment on the parking brake (there is a thread here on it if you dont have the shop manual) to make sure it is not adjusted too tight.

Also, can you post pics of the pistons when fully retracted? Curious to see if they are fully retracting