I am doing caliper rebuilding and pad replacement on the front today. Do I need to bleed the rear during this process or is that area isolated from the front?

You ought to bleed the rear as well.  Start with the Right-Rear (passenger side) as this is the furthest from the master cylinder.  I recently did mine and found that the bleeder screws were so rusted on my rear wheel cylinders that I sheared them off in the process.  The wheel cylinders were cheap enough and easy enough to replace, but I did have to wrap things up and run into town to replace them.

You ought to bleed the rear as well.  Start with the Right-Rear (passenger side) as this is the furthest from the master cylinder.  I recently did mine and found that the bleeder screws were so rusted on my rear wheel cylinders that I sheared them off in the process.  The wheel cylinders were cheap enough and easy enough to replace, but I did have to wrap things up and run into town to replace them.

 

Make sure to put the rubber caps back on the bleeder screws and keep the water and mud out of the bleed screws. I normally put a thin coat of anti-seize on the threads and then cap the bleeder screws. No issues with rust or stripping out.

Make sure to put the rubber caps back on the bleeder screws and keep the water and mud out of the bleed screws. I normally put a thin coat of anti-seize on the threads and then cap the bleeder screws. No issues with rust or stripping out.

That is what I did with the new ones.  I didn't have that option with the ones that rusted.

Hope I can get to the rear bleeders without jacking up the truck. I have a pressure bleeder system.

Hope I can get to the rear bleeders without jacking up the truck. I have a pressure bleeder system.

Do you have disk brakes on the rear?

Do you have disk brakes on the rear?

Yes. Drums would necessitate drum removal. I suppose worst case remove rear wheels on at a time .

Yes. Drums would necessitate drum removal. I suppose worst case remove rear wheels on at a time .

Drums don't necessarily require to be removed, but it is a little more awkward to get to without putting it up on jacks and removing the tire.  You can access the bleeder screws on your calipers with out jacking it up, but it would be a lot easier if you take the tire off. 

 

If you are rebuilding your front calipers, why not rebuild the rear calipers as well? The rebuild kits aren't too expensive, but the big advantage is cleaning all the garbage the builds up in caliper.  I was very surprised when I took my calipers apart.  There was quite a bit of sludge under the piston, in the bottom of the bore.

Cause the rears were done a year ago.

Sounds like a pretty good reason. Good luck, hopefully it all goes well.

What the frick size are the caliper bolts? 7mm too small, 8mm too big, 1/4" a bit to small.

Got out a mirror. It's torx. Online looks like T45 or T47

I spent more time chasing tools than I did getting the calipers to the shop. One side original Torx47. Other side 7mm allen. Here is a picture of how nasty the one caliper was. I bet 200,000 miles on these. One side pads were down to metal, other side Pistons not moving and pads 3/4 left. Guy who I bought the truck from was good at changing pads, fluids but not digging much deeper.

That can be cleaned up. It the outer weather boot that was damaged and needs replacing.

Just did mine  2 weeks ago..      This was my first   rebuild  on phenolic  pistons.      The steel   band on the  edge of my pistons  was rusted away,  so  I  wasn't too    gentle on  yanking them out.

Snapped onto them  with a vise grips,  and  twisted/pulled em right out.

IIRC   45   torx  was  the  size I used,  only because  one side  was too tight for a  47.     Funny how  rust  and or  dirt  can  change  how a   socket feels!!

 

I think  I had less than   18 bucks  in each side for  new hardware, pistons,  seals, and dust boots.   The new  slider pins  were not   torx..  just  a normal  hex head.    Used  permatex  brake lube  (purple stuff) 

 

 

I also tried those  speed bleeders  (one way check ball inside)        I gotta admit,  they worked!   Those were     about    7 bucks  for the pair.

Edited February 27, 201510 yr by rancherman

You might want to use compressed air to push the pistons out next time.  

Yep, I push mine in and out a few times after assembly to get brake fluid worked into the bores and seals. Use a thicker board to keep the pistons from coming clear out with compressed air. Apply brake fluid through the brake line hole and pop em. Love that sound! Amazing how much easier they move after rebuilding than before.

You might want to use compressed air to push the pistons out next time.

I certainly will.. when I know im going to reuse them! I had all 4 out in less time than it would've took me to walk across the shop to grab the air hose and nozzle..

Yeah but you didn't get to hear them pop out. Just remember to keep your fingers clear