Installing Kelsey Hayes Caliper Pistons ?

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Got the calipers tore down and pistons finally popped out. Got the pistons and seals ordered and should be here thursday. next is to clean up the bores..
Trying to picture how to go about putting the dust boots on FIRST, before the pistons go in..i took a quick shot at doing it that way when i was removing the pistons just to see and it seemed difficult with the boots already in place, but i didnt try too hard either as i had brake fluid everywhere..I know i am anxious to drive this car after all these years of wanting disc brakes!!
 
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Some good info here
Not to hijack thread. I picked up a set of KH calipers and they were previously redone by SSBC and have SS pistons in them
I won’t need them for awhile
Q1 Should I take them apart, clean and lube them for storage ?
Q2 Called SSBC they informed me I must use seals with a lip ?? At $35 each side for their seals who else makes the lip seals??
Thanks
 
barracudadave67 said:
Here in the rust belt..... some of those pistons can be really hard to remove. What I have done is drill a hole thru the piston(s) you are having trouble with, then tap threads into the piston. Screw a "long" grade 8 bolt with the end rounded off nicely, into the new threads, all the way in, keep tightening, this will push the pistons out. Use penetrating oil around the piston also. Drill piston in center. It works for me
Dave
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Now if you'd like to re-use the pistons, but can't get one or more to budge.
E-booger once suggested drilling a hole in the caliper body behind the piston(s) then knocking the pistons out with a punch.
He then tapped threads in the hole and sealed with a pipe plug.
 
sccachallenger said:
Now if you'd like to re-use the pistons, but can't get one or more to budge.
E-booger once suggested drilling a hole in the caliper body behind the piston(s) then knocking the pistons out with a punch.
He then tapped threads in the hole and sealed with a pipe plug.
Click to expand...
Boy oh boy, there sure seems to have been a lot of F*@^+D up methods in getting old, stuck, rusted, pistons, out of their caliper bores.
You don't have to drill holes, in the back of caliper bodies, drill holes in bottom of pistons, just pump them out hydraulically with a grease gun, putting a zerk fitting in one of the hard line threaded holes, and blocking the other hole off with a fine thread bolt.
Look at my previous postings for special tools that were used when they were available back in the dinosaur days, or use your noggin without having to drill holes, or F up a caliper.
Reply #22
 
When air didn't work, I would get a piece of wood like a 2x6, lay it on the ground, take the caliper with the piston(s) facing down( the way they come out) and slam the caliper on the wood. It will take several times and some force, but I have yet to see it not work. Now let all the haters chime in on how you will ruin the caliper. Not true.
 
SGBARRACUDA said:
When air didn't work, I would get a piece of wood like a 2x6, lay it on the ground, take the caliper with the piston(s) facing down( the way they come out) and slam the caliper on the wood. It will take several times and some force, but I have yet to see it not work. Now let all the haters chime in on how you will ruin the caliper. Not true.
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That ain't gonna work on the "small" half of the caliper.
Dunno, never heard of your method before.
Might work on the larger half of the caliper body.
Hydraulically, really would me the way to go.
Easy peasy.
 
Drilling a hole in the piston will not ruin the calipers. Pistons will probably have to be replaced if it gets to that point. All the ones that I took out like that, were badly pitted.
Dave
 
barracudadave67 said:
Drilling a hole in the piston will not ruin the calipers. Pistons will probably have to be replaced if it gets to that point. All the ones that I took out like that, were badly pitted.
Dave
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Then tell be what your gonna do if the caliper is stuck all the way down at the bottom of the bore?
Your drill is gonna go into the bottom of the bore, then the same thing with a tap.
People aren't using their noggin when it boils down to just using a bit of high school physics knowledge, and hydraulic pressure.

The grease gun method is "messy" but gets the job done.
And you have to limit the travel as one of the stuck pistons always works it way free first.
"C" clamps are your friend, doing the hydraulic method, or i use a block of wood between the caliper body half and the jaws of a bench vice.
Opening it when when a piston breaks free from the other, keeping them equal in the removal process.
 
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I use a silicone grease that I get from the Fuller transmission people, the outfit that brought us the 13 speed RoadRanger hiway tractor transmissions. And the 15s and the 18s and I heard recently 21s. I spent several years rebuilding those and I always got a tube of the grease with every kit. I had so many I couldn't get rid of them fast enough. Many of them ended up in my toolbox and here I am,33 years later still with a bit left. Thatchit is super slippery. Just a tiny bit goes a long long way.
When I am done I can spin the pistons in the bores using a snap-ring plier. It has to be this way because the only thing that releases the brakes is seal-retraction. So if the pistons are tight, she will burn the pads up. But if the seals are too slippery they may not retract the pistons either. To combat this I set my wheel bearings a tiny bit loose and let the rotors slap the pistons around, just a tiny bit. Works like a charm.
 
mopower440 said:
Let me ask you this..could i re-use my pistons and just run some smooth sand paper over them? I bought this whole brake setup freshly rebuilt about 16 years ago..new rotors, pads and rebuilt calipers. They spent the first few years in my house till i got my garage built and then they stayed in there until a few weeks ago when i FINALLY got around to doing this job. SO, i dont think they are in too bad of shape inside but i do think they are stuck because i took the car for a first drive yesterday after installing them and i have to literally stand on the pedal and it just barely slows down. Cant even lock them up in my gravel driveway!
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I don't think this is a caliper issue, maybe best to start a new thread
 
So, how do you get the pistons in if you install the dust boots first?
 
I recently rebuilt my KH calipers, and found the easiest way is to indeed put the seals and boots on the caliper first, then install the pistons. You just have to set the piston generally in place and gently pull up on one side of the dust boot, and then work it the rest of the way around until it's engaged in the groove in the piston. Kind of resembles a skirt. This actually locates your piston at this point, and then you can gently push straight in to work the piston down into the bore, past the seal.
 
I tried installing the skirt onto the piston first, but I got very frustrated as the lube is so slippery, it was impossible to keep it all together while fitting the skirt into the groove. I did a couple that way but jeepers it was hard.
So then I made a little circular metal sleeve to install in the skirts that expands them to a little larger than the piston.

I lube the sq-section seals all round, and stick them in the grooves, followed by the pistons to make sure it all goes together smoothly, then pull out the pistons. My goal is to grease the grooves with the silicone to prevent corrosion.
Next I lube the outter perimeter of the skirts, install them in their grooves. Then I install the sleeve I made.
Finally I wipe off the pistons a bit, and drop them back thru the skirt and into the seal, and remove the sleeve. Then I rotate the piston back and forth a lil to make sure everything is A-OK.
 
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