The right side caliper on my 172M has developed a leak. Looks like its coming from the piston seal on the side towards the front of the plane. It has McCauley calipers, C30018-9. Can we get seals for these? Or is it easier/better to send them out for rebuilding? Would be nice to get them blasted, honed, and painted as well. Suggestions on shops to send them to?

Thanks

UngaWunga wrote:The right side caliper on my 172M has developed a leak. Looks like its coming from the piston seal on the side towards the front of the plane. It has McCauley calipers, C30018-9. Can we get seals for these? Or is it easier/better to send them out for rebuilding? Would be nice to get them blasted, honed, and painted as well. Suggestions on shops to send them to?

Thanks

I have replaced the "O" rings many times and it works if there is no corrosion or pitting in the calipers. I have also seen many calipers that are unserviceable due to cracks, wear, and corrosion.

Use compressed air very gently to remove the Pistons! Inspect and go from there...

I would buy new Cleveland if you can not solve the problem. Nobody I know Yellow Tags McCauley calipers.

If you want to switch to clevelands I have a set of single puck calipers and discs I would sell. I removed from my 170 when I switched to double pucks,

Interesting info that may help keep the price of maintaining the brakes lower...

http://www.cessna172club.com/forum/ubbthreads.php?ubb=showflat&Number=165170

8GCBC wrote:

UngaWunga wrote:The right side caliper on my 172M has developed a leak. Looks like its coming from the piston seal on the side towards the front of the plane. It has McCauley calipers, C30018-9. Can we get seals for these? Or is it easier/better to send them out for rebuilding? Would be nice to get them blasted, honed, and painted as well. Suggestions on shops to send them to?

Thanks

I have replaced the "O" rings many times and it works if there is no corrosion or pitting in the calipers. I have also seen many calipers that are unserviceable due to cracks, wear, and corrosion.

Use compressed air very gently to remove the Pistons! Inspect and go from there...

I would buy new Cleveland if you can not solve the problem. Nobody I know Yellow Tags McCauley calipers.

Yeah... would love to. I'm not an AP. I've done it on motocycle and cars before... After the first time, I learned to wrap the calipers with a rag before using compressed air. You can also put a grease zerk on the caliper and use a grease gun to pop them out.

robw56 wrote:If you want to switch to clevelands I have a set of single puck calipers and discs I would sell. I removed from my 170 when I switched to double pucks,

Would they fit without changing the wheels? If you have some part numbers, I can start digging around. Let me know what you want for them in case we go that route. Thanks.

The complete wheel and brake kit is 199-46, the calipers are 30-63A. I'm not sure the P/N for the discs or if you could use them with your wheels.

If you need to buy time to locate a solution, new linings and o rings may do the trick. The linings can keep the piston up last the pitted area.

It is too bad you can't sleeve certificated calipers...these are sized to use cheap off the shelf sleeves, and the machine shop services might add up to an hour or so for both sides.

Here's a tip when reassembling the calipers after honing & replacing the o-ring -- push the piston ALL THE WAY into the caliper before replacing on the tork plate pins. Otherwise you will NEVER be able to bleed all the air out of the system. I know, simple, right? (so don't ask me how I know. )
Also, the brake system is easier to fill and bleed from the caliper end of the system with a small pump can & appropriately sized hose.

FWIW if you do have to replace a caliper, besides calling the salvage outfits, get ahold of Preferred Airparts & see if they have one. They carry a lot of "new old stock" parts. You'll need the correct part number.