front left caliper for 84

[FJ_Hooligan]

Hooli,

Great idea with the tie wrap I didn't think of that. How do you ensure the orifice that travels through the housing and the goop that builds up around the square cut o-ring is all cleaned out? Not all are extremely dirty but we have done more than our share of ones that come in here and have a good amount of sludge, either partially blocking the orifice or completely plugged up in between the caliper housings. We also work on a fair amount of bikes that have been sitting for awhile and have a good amount of moisture contamination.

Robert - RPM

Hi Robert.

From the "Not an oil thread" topic you will see that I don't have many brake fluid contamination issues on the FJ.  Because I'm too lazy to convert it, my FZ1 is still using DOT 4 fluid.  Over the past 14 years, I've flushed it a few times to keep the fluid fresh(ish).   

If I suspected severe contamination of the fluid with particulates in a 2 piece caliper, I would definitely split it open.  But ONLY after I removed the pistons.  :-)

[fjbiker84]

I would add that the mechanic who completed the job for me said that the crud inside my caliper cylinders was so bad that he had to use very fine sand paper to clean it off and resurface the metal.  No doubt this crud was the result of my bike having been stored for 7 years and although the brakes worked ok for the period before I had this work done, I had no idea how much better they could work have worked... because I had nothing to compare it to.  For any bike this age and if you have never done it before, I would recommend that you take the calipers off and then remove the pistons so that you can inspect and clean the cylinder walls.

[FJ1100mjk]

although the brakes worked ok for the period before I had this work done, I had no idea how much better they could work have worked... because I had nothing to compare it to.  For any bike this age and if you have never done it before, I would recommend that you take the calipers off and then remove the pistons so that you can inspect and clean the cylinder walls.

Not sure what brake pads you have on your bike, but if you want to realize even better brakes, deglaze the rotors, install EBC Double H pads, then break them in properly, and you'll be even happier with the brake performance.

[fjbiker84]

I put on new rotors and pads from a company called Bike Master several years ago in addition to the caliper work.  I forget now how I ran across this company but the description of the rotor set was that they were made of modern materials and a significant improvement to the old OE design. They do seem to work very well.

[Charlie-brm]

This is more fun than an oil thread

Just a couple of things I do when popping caliper pistons from several kinds of bikes. Yes, remove them from the bike and work at a bench.
With the pads and retaining hardware out of the way, I hold down one caliper with a 3 inch C clamp.

I ball up a rag or two into the gap between the cylinders. They act as a nice buffer and let the freed cylinder come out without slamming hard in to anything or coming out so far it's a loose cannon. Keep it under control. I don't want either cylinder all the way out until they are both extended enough that the hard part of extraction is done.

My blow nozzle has an optional conical rubber tip that seals really well when held in the hose fitting. What I've found is that it doesn't need a high continuous air pressure. What works best in my experience is to keep the nozzle held in firmly but key is to pulse the air trigger in short rapid bursts instead of holding it open. Like that, they come out in seconds.

Cleaning out the crud from the seal grooves - I do the bulk with a variety of hooked picks. Finish up with tightly twisted steel wool and absolutely blow away any possibility a strand of steel got anywhere in the caliper.

Replacing the cleaned up cylinders I use 2 wide gap slip joint pliers on exactly opposite points, slow and easy to keep everything level, because the tiniest skew in the entry of the cylinders and they just don't want to go in and more force will make it worse.

[ribbert]

This is more fun than an oil thread

And more likely to produce useful information. 

Noel

[fjbiker84]

After removing the caliper and inspecting it - turns out the leak was coming from one of the caliper pistons.  Fortunately I had a seal kit left over from three years ago when I had them rebuilt by a local mechanic.  Drove up to FJMonkey's place and he showed me how to rebuild the caliper with new seals.  Using air pressure, and clamping one piston in place, you carefully apply pressure to force one piston out.  Replace the seals and reinstall that piston before reversing the process and doing the other side. Thanks again, FJMonkey, for your help.  Unfortunately, as soon as I got home I discovered that my garage was flooding from all the rain here in SoCal.  Spent the remainder of the day teaching my FJ how to swim,,,,,

[big r]

Boy you guys are sure getting hammered down there. My daughter in Atlanta is in the same boat. Showed a picture of her front yard and there was about 8ins. of water in  it Big R