Slacker's Guide to Fixing Up the 68 Notch
My Cuda originally came with 10 inch drums all around and I plan to install KH disc brakes. I have a complete KH setup that I recently purchased from FABO member Demon540 from Wisconsin and I also purchased a second set of calipers from a local guy in the Phoenix area who has a real nice blue Duster 340. Seems like I got a pretty decent deal, but just like usual as soon as I buy something I see somebody selling a nicer set for less money!
So I thought I would document my disassembly and rebuild on the KH, maybe it will be helpful to others. This is pretty detailed, and you will probably find this boring unless you happen to be interesting in rebuilding a KH caliper. I fully acknowledge by posting activity so soon in my restoration thread I may lose my Slackers Association credentials, but I am almost positive I will make up for it later.
So I am starting with the 2 KH calipers I purchased here locally. I will keep my other 2 in reserve in case these have issues.
The first step was simply removing the disc pad retaining bolts with a 7/16" socket.
Both retainers removed.
Disc pads just easily pull up and out once retainers are removed.
Close up of 2 of the 4 caliper pistons. You can see they are a bit corroded. I tried to see if I could pull them out by applying finger force - no chance, they are in there good! I had been doing a little research on FABO to see what the best way to get these pistons out and it seemed the general consensus was either by air or using a grease gun to pressurize the caliper to push them out. Apparently there are some rare puller tools out there designed for KH pistons but the key word is rare (and probably expensive too). I also had seen on a Mustang site where somebody had used air successfully so that is the route I went.
My massive air compressor! Not as big as I would like, but it works for most of the things I need it for so far. 30 gallons, 120 v, and runs great. Bought it on sale a couple of years ago at Tractor Supply for $250, not bad I thought.
So this depicts my basic method of removing the caliper pistons: Closing two pistons down with clamps and applying air pressure to the inlet brake line hole. You can see where the 2 pistons popped out. On first caliper this worked great on all the pistons , on the second caliper I had one piston that was stubborn. I eventually got it to pop out a little where I was able to get a channel lock plier on it and work it out the rest of the way. I put the caliper in a box to do this since you get a some residual brake fluid that sprays out with the air pressure. You certainly would want to do this away from any vehicles since brake fluid can ruin paint.
In this pic you can see where I had already removed the pistons on the one caliper side, and now I am removing the crossover tube using 3/8 inch flare nut wrench and will blow air down that hole to remove the pistons on the opposite side. That piston on the upper right was the troublesome one. Once the pistons are removed you can just pull the 4 rubber dust seals out with your fingers. Just a note on the flare wrench - I did not have any SAE size flare wrenches in my toolbox so I ended up cheaping out and getting a set at Harbor Freight for about $10 with the obligatory 20% off coupon. Worked great on this project - can't complain.
So this is what I ended up with after removing all the caliper pistons and dust seals.
I just noticed at this point one of the calipers was missing a bolt. This bolt hold the 2 caliper halves together. I took the other one out and will see if I can match it up with a grade 8 bolt at Ace Hardware. It looks like about a 9/16 x 2 inch bolt, so hopefully will not be hard to find.
This is what I am seeing inside the caliper cylinders with piston removed. Some corrosion but most places I do not think too bad. This is about the worst. My thought is the caliper piston seals against the rubber ring inside, and as long as it moves smoothly in the cylinder that a little corrosion is not a big deal as it would be in a drum brake wheel cylinder. Anybody ever honed these?
I used a brass pick to pull out the rubber ring seals in the piston cylinders. Somewhere I read not to use steel picks as to avoid scratching the groove. After seeing how easy the seals came out, I could have easily got them with my regular steel picks without issue.
Just in case you were interested in knowing where I got my picks. Amazon for about $11. Anybody remember the smell of Hoppes gun cleaner? These brass picks are pretty decent and now that I have them they will probably come in handy for cleaning guns!
Pic shows the machined grooves after I removed the seals. The first groove is where the dust seal fits it, the second groove is where the fluid seal fits in. Some folks on FABO have posted that this second groove really needs to be clean and good shape or you will run into sealing problems. This particular cylinder was the worst of the eight. After I took the pic I was able to pick a fair amount of the brown corrosion/goop out of there with the brass pick. Hopefully it will be okay after I degrease it and de-rust it.
So my next step was just spraying all the parts down with this degreaser, letting sit for a few minutes, then brushing thoroughly with a toothbrush. I then rinsed it off with water and dried if off with rags. After that I placed the parts in a bucket filled with Evaporust. I don't know much about this degreaser, just saw it in Home Depot and decided to give it a try. It kind of burns my lungs and skin and so it must be good! If you have a better degreaser choice please shout out.
Here is the bucket I used for the Evaporust. A $3 buck Home Depot 5 gallon bucket with a Gamma Seal on it. I occasionally have a few grandkids running around so this seal reduces the worry about them tipping over the bucket.
If you haven't used these Gamma lids before, they are pretty nice. They run about $7 at Home Depot and make your bucket air and water tight. I have about 2 gallons of Evaporust poured in waiting for duty.
Inside I have all my caliper parts peacefully soaking in Evaporust. I have several questions about Evaporust such as how long should I soak and how many times can I use the same solution - I will probably post a new thread to ask that specifically. Feel free to chime in if you have any experience or a scientific guess. I plan in my next report to show the rust removal results - stay tuned.
My Cuda originally came with 10 inch drums all around and I plan to install KH disc brakes. I have a complete KH setup that I recently purchased from FABO member Demon540 from Wisconsin and I also purchased a second set of calipers from a local guy in the Phoenix area who has a real nice blue Duster 340. Seems like I got a pretty decent deal, but just like usual as soon as I buy something I see somebody selling a nicer set for less money!
So I thought I would document my disassembly and rebuild on the KH, maybe it will be helpful to others. This is pretty detailed, and you will probably find this boring unless you happen to be interesting in rebuilding a KH caliper. I fully acknowledge by posting activity so soon in my restoration thread I may lose my Slackers Association credentials, but I am almost positive I will make up for it later.
So I am starting with the 2 KH calipers I purchased here locally. I will keep my other 2 in reserve in case these have issues.
The first step was simply removing the disc pad retaining bolts with a 7/16" socket.
Both retainers removed.
Disc pads just easily pull up and out once retainers are removed.
Close up of 2 of the 4 caliper pistons. You can see they are a bit corroded. I tried to see if I could pull them out by applying finger force - no chance, they are in there good! I had been doing a little research on FABO to see what the best way to get these pistons out and it seemed the general consensus was either by air or using a grease gun to pressurize the caliper to push them out. Apparently there are some rare puller tools out there designed for KH pistons but the key word is rare (and probably expensive too). I also had seen on a Mustang site where somebody had used air successfully so that is the route I went.
My massive air compressor! Not as big as I would like, but it works for most of the things I need it for so far. 30 gallons, 120 v, and runs great. Bought it on sale a couple of years ago at Tractor Supply for $250, not bad I thought.
So this depicts my basic method of removing the caliper pistons: Closing two pistons down with clamps and applying air pressure to the inlet brake line hole. You can see where the 2 pistons popped out. On first caliper this worked great on all the pistons , on the second caliper I had one piston that was stubborn. I eventually got it to pop out a little where I was able to get a channel lock plier on it and work it out the rest of the way. I put the caliper in a box to do this since you get a some residual brake fluid that sprays out with the air pressure. You certainly would want to do this away from any vehicles since brake fluid can ruin paint.
In this pic you can see where I had already removed the pistons on the one caliper side, and now I am removing the crossover tube using 3/8 inch flare nut wrench and will blow air down that hole to remove the pistons on the opposite side. That piston on the upper right was the troublesome one. Once the pistons are removed you can just pull the 4 rubber dust seals out with your fingers. Just a note on the flare wrench - I did not have any SAE size flare wrenches in my toolbox so I ended up cheaping out and getting a set at Harbor Freight for about $10 with the obligatory 20% off coupon. Worked great on this project - can't complain.
So this is what I ended up with after removing all the caliper pistons and dust seals.
I just noticed at this point one of the calipers was missing a bolt. This bolt hold the 2 caliper halves together. I took the other one out and will see if I can match it up with a grade 8 bolt at Ace Hardware. It looks like about a 9/16 x 2 inch bolt, so hopefully will not be hard to find.
This is what I am seeing inside the caliper cylinders with piston removed. Some corrosion but most places I do not think too bad. This is about the worst. My thought is the caliper piston seals against the rubber ring inside, and as long as it moves smoothly in the cylinder that a little corrosion is not a big deal as it would be in a drum brake wheel cylinder. Anybody ever honed these?
I used a brass pick to pull out the rubber ring seals in the piston cylinders. Somewhere I read not to use steel picks as to avoid scratching the groove. After seeing how easy the seals came out, I could have easily got them with my regular steel picks without issue.
Just in case you were interested in knowing where I got my picks. Amazon for about $11. Anybody remember the smell of Hoppes gun cleaner? These brass picks are pretty decent and now that I have them they will probably come in handy for cleaning guns!
Pic shows the machined grooves after I removed the seals. The first groove is where the dust seal fits it, the second groove is where the fluid seal fits in. Some folks on FABO have posted that this second groove really needs to be clean and good shape or you will run into sealing problems. This particular cylinder was the worst of the eight. After I took the pic I was able to pick a fair amount of the brown corrosion/goop out of there with the brass pick. Hopefully it will be okay after I degrease it and de-rust it.
So my next step was just spraying all the parts down with this degreaser, letting sit for a few minutes, then brushing thoroughly with a toothbrush. I then rinsed it off with water and dried if off with rags. After that I placed the parts in a bucket filled with Evaporust. I don't know much about this degreaser, just saw it in Home Depot and decided to give it a try. It kind of burns my lungs and skin and so it must be good! If you have a better degreaser choice please shout out.
Here is the bucket I used for the Evaporust. A $3 buck Home Depot 5 gallon bucket with a Gamma Seal on it. I occasionally have a few grandkids running around so this seal reduces the worry about them tipping over the bucket.
If you haven't used these Gamma lids before, they are pretty nice. They run about $7 at Home Depot and make your bucket air and water tight. I have about 2 gallons of Evaporust poured in waiting for duty.
Inside I have all my caliper parts peacefully soaking in Evaporust. I have several questions about Evaporust such as how long should I soak and how many times can I use the same solution - I will probably post a new thread to ask that specifically. Feel free to chime in if you have any experience or a scientific guess. I plan in my next report to show the rust removal results - stay tuned.