Rebuilding Calipers

[bucks77ford]

I'm considering rebuilding some old dual piston calipers for my truck. My plan is to take them apart, powder coat them and rebuild them. Never done it before and wondering what the trick is to get the pistons out.

 

[smokey]

Cheaper and easier to buy new ones than to rebuild them in most cases.

 

[Fellro]

Being dual piston makes it even more fun, but to get them out, usually hit them with air pressure. I don't know how to get two out though, since most likely one will pop out and one will stay. If you put them in a bit crooked or such, they will bind, and you have big problems.

 

[m78]

Being dual piston makes it even more fun, but to get them out, usually hit them with air pressure. I don't know how to get two out though, since most likely one will pop out and one will stay. If you put them in a bit crooked or such, they will bind, and you have big problems.

Put the calipers piston down to the cement with weight on top before pressurizing. Hopefully making the pistons come out evenly and at the same time.

 

[bucks77ford]

Cheaper and easier to buy new ones than to rebuild them in most cases.

Ya, I bought new ones and they are on the truck now. I just kept my old ones just in case. In order to powder coat the caliper, I need to have all the components out to bake the coating. I just thought that it would give me something to learn in the meantime. I'm not out much if I can't rebuild them or screw something up.

Put the calipers piston down to the cement with weight on top before pressurizing. Hopefully making the pistons come out evenly and at the same time.

I'll try that. I won't get around to try anything real soon, but if you think of any more tricks that would be great.

 

[Fellro]

I do remember from tech school to put a board in between the pistons and the caliper frame. That keeps them from blowing way out.

 

[Mil1ion]

Boy it 's been 20+ years since I rebuilt brake calipers.


Let's hope you have all the tools and supplies to make it easier

 

[bucks77ford]

Boy it 's been 20+ years since I rebuilt brake calipers.


Let's hope you have all the tools and supplies to make it easier

I have really no idea what I need. Reason why I better ask before I just start trying.

 

[BuzzGun79]

Yes its been awhile for me as well,i always used compressed air,a good volume of it,to get them out,as stated.cleanliness of the pistons & caliper bores are very important.when i reassembled them i used a thin coat of vaseline on the pistons as well to aid in getting the pistons to slide in the bores with ease & not damage the rubber seals,.never had no trouble doing this.& they worked just fine.

 

[primetime]

Per a Motor truck repair manual, 1970-1981.

Disassembly

To remove pistons, apply air pressure to the caliper fluid port to ease the pistons from the bores. Use a block of wood and a shop towel to protect pistons from damage. (Brake systems operate around 1000 psi, so the 100-150 your compressor operates at could be considered low. However, I would start low with the air pressure and go from there. Maybe even use a c-clamp and a brake pad to keep the pistons equal).

Remove cylinder housing to caliper attaching bolts and separate housing from caliper.

Remove piston seals.

Assembly

Lubricate cylinder bores and new piston seals with brake fluid.

Install piston seals in cylinder bore grooves.

Lubricate pistons with brake fluid and insert pistons into dust boots. Start pistons into cylinders until located beyond the piston seals.

Place a block of wood over one piston and press into cylinder being sure not to damage seal or piston. Press the second piston into the bore.

Place piston housing on caliper and torque mounting bolts to 155-185 ft. lbs.

There`s no mention of tools, although for other calipers, such as a Bendix, there is.

The above is for a Ford Dayton dual piston caliper. Hope it helps.