Has anyone done this who can advise me on any tricks to this? Also, I assume there is an internal o-ring so I need a source for this item and torque spec on the caliper bolts.
I need to thoroughly clean the piston bores and don't see a good way to this without straight in access.
Best way I have found is to remove the pads and put in a a spacer block 1/2 inch? in place of the pads. Blow compressed air into the brake hose hole to push out the pistons, then unbolt the 2 halves to complete piston removal.
The O rings are actually square and the pistons ride on them, rather than the actual bore (no metal to metal contact).
I have heard that for really stubborn stuck pistons that pumping in grease from a gun will usually work, but then you have to clean all the grease out.
Try to make sure all 4 pistons are mostly popped out before separating the halves.
There is no internal fluid transfer o-ring, just the bridge transfer line. Shoud be able to look up torque on any bolt table.
Does anyone still offer the stainless steel sleeving service if the bores are bad?
Quote from: kram350 on October 17, 2025, 09:12:57 PMThere is no internal fluid transfer o-ring, just the bridge transfer line. Shoud be able to look up torque on any bolt table.
Ah yes, good point! So this is not as big a deal as I feared so long as the bolts come out.
The pistons on one caliper came out with compressed air (loudly) but the other side was very stuck and required the grease gun approach, which was messy but quiet. ;D
Unless the caliper cylinders are really pitted where the piston seal sits, which is pretty rare, a new piston and seal will work. The Kelsey caliper design seals on the piston not the cylinder,just opposite of an engine piston ring and how it seals. Some GM and other make calipers have their seals on the piston making their seal on the cylinder, hence the need to sleeve corroded cylinders to get a renewed sealing surface. Again, unless you have some horrendous corrosion around the seal groove in the caliper, new (stainless steel) pistons will suffice on most rebuilds.
It looks like White Post Restorations still resleeves brake parts:
https://whitepost.com/brake-sleeving-rebuilding-services/
I imagine the sleeve will have the groove for the seal but I have never seen one they have done.
There is a special tool to get the piston out if they are stuck. I often see them on ebay. It's K-dee tool #2105
I found the torque spec for these "bridge bolts" in the shop manual. 65-75 ft.-lbs.
Quote from: rockhouse66 on October 21, 2025, 07:42:39 AMI found the torque spec . . . . in the shop manual.
Not disputing the "spec.", but rather just a general thought:
As good as the manuals are, and with generally the notion that one should follow the information provided religiously, remember you are in the end the one with the "responsibility" to draw the proper conclusions in executing the process. So always weigh that information as supplied "with a grain of salt". :o
In the case of torque specs., always look at the fastener and give consideration as to whether the specification outlined seems "reasonable" for what you might be holding in your hand. ;)
Scott.
Quote from: rockhouse66 on October 17, 2025, 03:53:38 PMHas anyone done this who can advise me on any tricks to this? Also, I assume there is an internal o-ring so I need a source for this item and torque spec on the caliper bolts.
I need to thoroughly clean the piston bores and don't see a good way to this without straight in access.
When we did our 66 GTH we used compressed air to push the pistons out. Then cleaned the pistons, slight cylinder cleaning/ honing, new rebuild kits. That's it