View Full Version : FJ40 calipers - rebuild/replace?
08-10-2012, 10:00 AM
My FJ40 front calipers (4 piston, stock '78) are original to the truck and are dragging and cause brake noise all the time. I bought a Toyota caliper rebuild kit many years ago, but some folks on Mud just suggested buying reman calipers at a parts store. The thought of A1 Cardone reman stuff gives me chills, but the thought of a total caliper teardown is another time-suck.
Has anyone in RS rebuilt their own 4 piston Toyota calipers and had good luck with it? It's a bit more involved than doing a single piston caliper on a domestic vehicle.
Thoughts? Should I just man-up and rebuild my own? Thanks!
08-10-2012, 10:10 AM
Ive done all.mine. pretty simple. Getting the pistons out is the worst ..on blows out the rest need work
08-10-2012, 10:15 AM
it's easy. just stick a piece of wood in the middle of it that won't let the pistons come all the way out and apply air pressure as Ige suggests. They'll pop out most of the time, sometimes pretty quickly (like really fast... take fingers off fast) so make sure the area they will shoot out through is clear of fingers.
if one sticks, you can work it with the others still "kinda" in.
then once they are all pretty much out but still hangin in their bores, remove the wood and finish popping them out.
08-10-2012, 01:16 PM
Thanks - those are the hints I needed - I suspected that one would come out and the others would stick. I have the FSM, so I presume you go by that to reassemble.
08-23-2012, 02:44 PM
I went through the same thing a few months ago on my 77 fj40. I just put rebuilt calipers on it. For the price I couldn't beat it (35 bucks a piece). Don't forget to adjust those rear brakes up, man that makes a huge difference on trucks with rear drums.
08-23-2012, 03:18 PM
I bought some disk brake caliper grease (apparently ok to use on seals/rubber) and ordered Marlin inner axle seals and decided to go whole-hog and tear down the front end and replace the seals, repack the birfields, and rebuild the brake calipers.
One of my rear adjuster screws is seized, but you're absolutely right about keeping the rear brakes tight. It also helps your booster and MC last longer when they aren't making such a long stroke (with ill-adjusted brakes) to stop the truck.
08-23-2012, 04:46 PM
I would only use brake fluid on the o-rings for the pistons.
08-23-2012, 04:53 PM
Thanks for the suggestion, Marco!
I agree that brake fluid is surely compatible, but others suggested using a rubber-compatible grease. I guess I can try it with brake fluid and if it all goes together nicely (it should), then skip the grease.
07-02-2013, 04:38 PM
Update on this ancient thread:
Finally got the axle rebuilt (with the help of my 15 year old daughter) and both calipers rebuilt. I can see why people just buy reman calipers, since it's a somewhat annoying job to redo the calipers. But, since I had a caliper rebuild kit I purchased exactly 20 years ago, I figured I had better use it.
The pistons in each caliper were not rusty, just scummy and gooey from 35 years of accumulated sludge in the calipers. I used a combination of old and new brake pads as the 'block of wood' in the FSM against which to blow out the pistons - that worked nicely. The FSM recommended greasing the pistons and seals so I used a small pouch of synthetic brake grease on the pistons. Bleeding was a bit more involved, too, when you totally empty a pair of calipers.
The result is brakes that feel more responsive and require less effort. I still have a totally factory (1978 disk/drum) setup, but it feels nice. Since the old pistons were very difficult to blow out, I'm sure they were hanging up in the bore when I applied the brakes.
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