Topic: CB750K2 Front Brake Caliper

[Pwrwagontom]

Hey guys, new here to the forum.
I purchased a 1972 Honda CB750K2 a few weeks ago, and the only thing which needs to be done is the front brakes.  I've got the caliper apart, piston removed, and a new piston and parts to rebuild it, etc.

Looking for tips on two things- first, the brake pad (on not the piston side) is stuck to the housing, even after soaking in fluid and whacking it.  Worried that too much messing around will damage the housing, any tips for me?

Secondly, any tips on the best way to clean out the slot for the gasket?  I've cut up a credit card, used 320 grit sandpaper, and gently used a dentists tool.  The rest of the housing looks good, but I'd like to get this slot a little cleaner.


Thanks in advance!

Tom

[Flyin900]

There is a small cotter pin that holds the brake pad in the non caliper piston side have you removed that from the plate? I have a bunch of small 1 " fine steel wire wheels that attach to my power drill and they work wonders on cleaning out the slot for the rubber caliper seal.
Most tool supply places will sell these as either original Dremel accessories or a knock off part for Dremel tools which is what I have used. (Much cheaper than original Dremel parts) I bought a whack of them off Amazon in both a brass and fine steel bristle in a variety of designs for dirt cheap. If you only need a one time job part then probably the Dremel small kit is your best bet.
These are such a fine wire bristle that no damage is done to the groove, yet all the old dried brake fluid is cleaned right out of the slot perfectly.

[ekpent]

+1 on a dremel and wire wheel to clean the groove.Makes very quick work of it. If you have the cotter pin out on the stationary side of the caliper the pad may just be jammed in there. Gently prying around the edgeswith a screwdriver,tapping with a hammer on both the brake pad face and a punch on the pin that goes through can help. Don't throw away the screw that goes on the pad edge that moves on the other side when you remove that pad as most new pads don't come with one if your replacing.

[Pwrwagontom]

+1 on a dremel and wire wheel to clean the groove.Makes very quick work of it. If you have the cotter pin out on the stationary side of the caliper the pad may just be jammed in there. Gently prying around the edgeswith a screwdriver,tapping with a hammer on both the brake pad face and a punch on the pin that goes through can help. Don't throw away the screw that goes on the pad edge that moves on the other side when you remove that pad as most new pads don't come with one if your replacing.

Ohh I'm glad you said that, just caught me throwing away the old pads!
I'm going to head down to the hardware store tonight and see if I can find some of those dremel pads...brass would be even better, I know they make it.

I've got the cotter pin removed, and have been prying at the pad every day, no luck yet. Guess I'll keep it going!

There is a small cotter pin that holds the brake pad in the non caliper piston side have you removed that from the plate? I have a bunch of small 1 " fine steel wire wheels that attach to my power drill and they work wonders on cleaning out the slot for the rubber caliper seal.
Most tool supply places will sell these as either original Dremel accessories or a knock off part for Dremel tools which is what I have used. (Much cheaper than original Dremel parts) I bought a whack of them off Amazon in both a brass and fine steel bristle in a variety of designs for dirt cheap. If you only need a one time job part then probably the Dremel small kit is your best bet.
These are such a fine wire bristle that no damage is done to the groove, yet all the old dried brake fluid is cleaned right out of the slot perfectly.

I think power tools is probably the way to go here, I agree.  I wanted to hold off until I got some feedback from the members.

Ill post my results.

Thanks guys!

[Pwrwagontom]

Getting a little frustrated, that outside brake pad is REALLY stuck on there! Been hammering and prying away with no luck. Concerned I'll damage the housing.

[Yamahawk]

Getting a little frustrated, that outside brake pad is REALLY stuck on there! Been hammering and prying away with no luck. Concerned I'll damage the housing.

Post a picture of your caliper and pad, and let's see what you are up against. Add a couple of them so we get a good multi point view. Thanks!
Charlie

[Pwrwagontom]

Sure thing!  See below.

Now to preface this- I realize that this may not look to bad, but that is because I've already cleaned out all the crystallized brake fluid/surface rust/gunk.

I got a chisel today and attempted to wedge it behind the bad, but as you can see, it just began to break it off in chunks.  I currently have it sitting in a bucket of brake fluid to try and loosen things.

[Yamahawk]

Awesome! That's a good picture, and Cal was able to see what needed done, and now... you are all set!
Charlie

[seanbarney41]

better than clamping it, just adjust the vice jaws so that the housing is supported but the brake pad is not and simply punch the dowel through

[evanphi]

better than clamping it, just adjust the vice jaws so that the housing is supported but the brake pad is not and simply punch the dowel through

This is also what I have done.

[pjlogue]

Try putting it in boiling water for a few minutes then put it face down on the open jaws of the vise and tap the dowel to drive the puck out.  Don't wail on it though.

-P.

[Pwrwagontom]

Success!
I let it sit submerged in brake fluid for 24 hours, and was then able to drive the dowel out with a punch fairly easily. As expected, the rear was entirely a paste made of brake fluid and rust.

Thanks everyone for the input!
Maybe someone else having this issue can find the thread...


Tom

[Yamahawk]

Success!
I let it sit submerged in brake fluid for 24 hours, and was then able to drive the dowel out with a punch fairly easily. As expected, the rear was entirely a paste made of brake fluid and rust.

Thanks everyone for the input!
Maybe someone else having this issue can find the thread...


Tom

You may want to put a thin layer of never seize on the rear of the cover where the back of the pad sits, to make it easier next time. I don't slather it on, and I use a rag or my finger to kind of 'burnish' the anti-seize into the metal. Don't let it get on any of your brake pad area! Use very sparingly, and if you get too much, wipe it off.... of your fingers, nose, clothes, left toe... it seems to get EVERYWHERE...
Charlie

[ekpent]

  How much you want for that rare used stock brake pad      Congrats on giving that pin a good whack,now you can move on to more fun stuff !

[evanphi]

Glad it all worked out. Now you have a souvenir!

[Pwrwagontom]

Glad it all worked out. Now you have a souvenir!

Definitely going on the wall of shame.

For anyone else with this issue-

The bronze wheel for the Dremel worked ok, but dissolved fast. I think the best tool is what was recommended above, a steel brush wheel for the dremel.

[Pwrwagontom]

Success!
I let it sit submerged in brake fluid for 24 hours, and was then able to drive the dowel out with a punch fairly easily. As expected, the rear was entirely a paste made of brake fluid and rust.

Thanks everyone for the input!
Maybe someone else having this issue can find the thread...


Tom

You may want to put a thin layer of never seize on the rear of the cover where the back of the pad sits, to make it easier next time. I don't slather it on, and I use a rag or my finger to kind of 'burnish' the anti-seize into the metal. Don't let it get on any of your brake pad area! Use very sparingly, and if you get too much, wipe it off.... of your fingers, nose, clothes, left toe... it seems to get EVERYWHERE...
Charlie

Is this instead of the silicone brake grease?

[Yamahawk]

Success!
I let it sit submerged in brake fluid for 24 hours, and was then able to drive the dowel out with a punch fairly easily. As expected, the rear was entirely a paste made of brake fluid and rust.

Thanks everyone for the input!
Maybe someone else having this issue can find the thread...


Tom

You may want to put a thin layer of never seize on the rear of the cover where the back of the pad sits, to make it easier next time. I don't slather it on, and I use a rag or my finger to kind of 'burnish' the anti-seize into the metal. Don't let it get on any of your brake pad area! Use very sparingly, and if you get too much, wipe it off.... of your fingers, nose, clothes, left toe... it seems to get EVERYWHERE...
Charlie

Is this instead of the silicone brake grease?

I have found that never seize lives up to it's name... so, in areas prone to things corroding or being stuck, I use it first. You brake pad will most likely come out next time if you use it.
Charlie

[evanphi]

Success!
I let it sit submerged in brake fluid for 24 hours, and was then able to drive the dowel out with a punch fairly easily. As expected, the rear was entirely a paste made of brake fluid and rust.

Thanks everyone for the input!
Maybe someone else having this issue can find the thread...


Tom

You may want to put a thin layer of never seize on the rear of the cover where the back of the pad sits, to make it easier next time. I don't slather it on, and I use a rag or my finger to kind of 'burnish' the anti-seize into the metal. Don't let it get on any of your brake pad area! Use very sparingly, and if you get too much, wipe it off.... of your fingers, nose, clothes, left toe... it seems to get EVERYWHERE...
Charlie

Is this instead of the silicone brake grease?

I used anti-seize because I DIDN'T have any silicone grease. If you have the good Dow Corning stuff, use the silicone grease.

[ekpent]

 I have done a lot of different 750 front brakes and must say yours looked/sounded to be corroded to the extreme. Maybe it sat outside at one time or something but by and large those stationary pads getting stuck that bad is not a common occurrence.  Little bit of high temp brake goo on the back should be fine.
  When you put everything back together the piston should be able to be pushed in fairly easily with your hand and make sure the new brake pads also slide in and out easily. Some of the new ones needed to be 'dressed' up a little on the outside edge to work smoothly like removing paint etc..