2004 TSX Caliper front piston will not compress

[Raf99]

So doing the front brakes and pads on my 2004 TSX. Done this before on other cars, no issues. Un-screwed the brake master cylinder cap.

Started on drivers side. Did the usual steps, compressed piston, re-assembled, no issues.

Did passenger side and the piston will not compress. Not even 1mm. I still have a good 1/4" that I need it to compress too.

What I think is going on:
- I was using a clamp so maybe the piston got wedged offset/sideways. Doubt it as it never moved 1mm as I was watching it when applying pressure
- Seized piston. Not sure how to get it moving here besides trying to make it come out then push it back in

I'm going to go buy a piston compression tool after work today. Besides this the only other thing I can think of is loosening the bleeder screw on that caliper while pushing it in. I doubt this will make any difference.


Just wanted to see if anyone had any ideas. The caliper doesn't look old, no torn boots, etc. Also the piston does not turn, it's not a turn style type of piston (just hollow).

[owequitit]

So doing the front brakes and pads on my 2004 TSX. Done this before on other cars, no issues. Un-screwed the brake master cylinder cap.

Started on drivers side. Did the usual steps, compressed piston, re-assembled, no issues.

Did passenger side and the piston will not compress. Not even 1mm. I still have a good 1/4" that I need it to compress too.

What I think is going on:
- I was using a clamp so maybe the piston got wedged offset/sideways. Doubt it as it never moved 1mm as I was watching it when applying pressure
- Seized piston. Not sure how to get it moving here besides trying to make it come out then push it back in

I'm going to go buy a piston compression tool after work today. Besides this the only other thing I can think of is loosening the bleeder screw on that caliper while pushing it in. I doubt this will make any difference.


Just wanted to see if anyone had any ideas. The caliper doesn't look old, no torn boots, etc. Also the piston does not turn, it's not a turn style type of piston (just hollow).

Probably a frozen piston. Or the bore could have corrosion damage internally that will not allow it to go back in once it comes out, but I would suspect a caliper problem.

[Raf99]

Probably a frozen piston. Or the bore could have corrosion damage internally that will not allow it to go back in once it comes out, but I would suspect a caliper problem.

Thanks for replying. I went and bought a proper caliper piston push tool this afternoon. I'm hoping its not the piston. I think you may agree that i shouldn't have to unscrew the bleeder valve to compress the piston in? (just take some fluid out of the master cylinder)

[owequitit]

Thanks for replying. I went and bought a proper caliper piston push tool this afternoon. I'm hoping its not the piston. I think you may agree that i shouldn't have to unscrew the bleeder valve to compress the piston in? (just take some fluid out of the master cylinder)

Not unless there is some other problem in the system. With the brakes released, the fluid should be able to flow freely back into the reservoir, no bleed bolt required. I am also about 100% sure that the piston should have gone back in with the C-clamp, as I haven't ever had a problem with that in the literally decades I have been retracting brake pistons. If it did get sideways in the bore a little bit, you could re-install the caliper, pump the brakes a few times, and then try it again. But I think you are going to find it needs a caliper.

[XCRN]

If you find that the caliper is seized you could rebuild it for cheap. On my BMW it was $40 for all 4 calipers, did not get new pistons for all though just one piston and that was still only $15 online. It is real simple to rebuild calipers, but it can be a PITA to put the piston back in but not impossible.

[Raf99]

wow........ everything just needs to be replaced.

Went and bought rotors today. Decided I'd try some things on the caliper first.

- Using the proper compress tool, it didn't budge
- Loosen the bleeder screw ...... wait. Bleeder screw rusted shut too
- Loosen the banjo bolt for hose and fluid came out. But it did not compress anymore.

- Clamped hose, took caliper off & over to the bench. Only then would the piston compress but obviously ....not working 100%.
- Got bleeder screw out and functioning again.

..... Attempted to get the old rotors off..... . NO F'N WAY. They are rusted on there too.


Sooooo got caliper working, but can't get rotors off. Got rusty crusty shitty rotors rubbing against new pads and anti-rattle clips. And an Acura appointment tomorrow at 1pm to replace a AC compressor. UG.