Today I noticed that my front left caliper has developed a very slight leak that appears to be coming from the caliper body. I had the caliper rebuilt with the help of a local mechanic several years ago. After splitting apart the caliper I was made aware of two small rubber gaskets that seat in the oil passages between the two halves of the caliper body and are not available. If this is where the leak is coming from what are my options? It appears that the entire caliper assembly is no longer available. :Facepalm:
Here ya go...
https://www.rpmracingca.com/proddetail.asp?prod=M%2FC%3ACaliperORing (https://www.rpmracingca.com/proddetail.asp?prod=M%2FC%3ACaliperORing)
Thanks!!! :good2:
Go to a a bearing supplier or a brake shop with a caliper half and they will fix you up. I get all my seals and o rings from an industrial bearing supplier.
Don't fret, this is not a big deal.
Noel
Yes, thanks. I panicked when I first discovered the problem but all is resolved now. I've ordered three sets of these little gaskets from RPM. Nice to have replacements for the other calipers even if they aren't leaking at the moment.
Just a bit of thread hijack: is it needed to split the calipers in order to change the seals around pistons (and pistons)?
This is a photo of the caliper split apart when I was attempting to rebuilt it several years ago. This is as far as I could get because I couldn't pull out the pistons without risking damage to the pistons. According to the mechanic who did the work, my caliper pistons were so gummed up that he had to put the calipers back together, hook it up to one of his bikes, and use hydraulic pressure to push the pistons out far enough to then split the caliper apart and pull the pistons out. The two small gaskets are the things I think are leaking now. Yamaha apparently never sold these separately. Fortunately RPM does!
Quote from: fjbiker84 on January 17, 2017, 09:16:47 PM
This is a photo of the caliper split apart when I was attempting to rebuilt it several years ago. This is as far as I could get because I couldn't pull out the pistons without risking damage to the pistons. According to the mechanic who did the work, my caliper pistons were so gummed up that he had to put the calipers back together, hook it up to one of his bikes, and use hydraulic pressure to push the pistons out far enough to then split the caliper apart and pull the pistons out. The two small gaskets are the things I think are leaking now. Yamaha apparently never sold these separately. Fortunately RPM does!
As far as I know you ARE supposed to push the pistons out with the calipers mounted. Otherwise, it is (almost) impossible.
But no one replied to my question posted earlier....
Quote from: balky1 on January 18, 2017, 12:51:49 AM
As far as I know you ARE supposed to push the pistons out with the calipers mounted. Otherwise, it is (almost) impossible.
But no one replied to my question posted earlier....
I used an air compressor with a blow gun tip, to pop out the pistons. You have to be careful. Don't put your fingers where they shouldn't be. Also heard that a grease gun will fit the bleeder screw. Plug the fluid port, and pump the caliper with grease, and the grease will pop out the pistons. Sounds messy, but possibly effective. Never tried it though.
Quote from: FJ1100mjk on January 18, 2017, 04:43:46 AM
Quote from: balky1 on January 18, 2017, 12:51:49 AM
As far as I know you ARE supposed to push the pistons out with the calipers mounted. Otherwise, it is (almost) impossible.
But no one replied to my question posted earlier....
I used an air compressor with a blow gun tip, to pop out the pistons. You have to be careful. Don't put your fingers where they shouldn't be. Also heard that a grease gun will fit the bleeder screw. Plug the fluid port, and pump the caliper with grease, and the grease will pop out the pistons. Sounds messy, but possibly effective. Never tried it though.
Yes, I forgot the compressor. But if you don't have one.... Since you are mentioning puting fingers in wrong place, I suppose you didn't need to split the calipers to pop them out? Trying and trying to get this answer.... :wacko1: :ireful: :mad:
Do a Google search with this: using air pressure to remove motorcycle caliper pistons youtube
You will have a couple of videos to look at, that provide direction.
I just pulled a new set caliper pistons and set them up to a set of calipers. Yes, you may be able to get the pistons out, if you have something thin enough to clamp the other side of the caliper and hold the other piston in, as the caliper is not wide enough to have both come out at once. Also, considering all the goop and grudge that usually builds up behind the o-rings in the caliper housing and how much of a pain it would be to get all of that cleaned out of there without splitting the caliper. It seems like you would be wasting much more time trying to screw around with not dis-assembling the caliper in the first place.
So to answer your question, yes, you could get away with not splitting the caliper.
Robert - RPM
Here's how I remove the pistons without splitting the caliper.
Tie wrap one piston in place and use air or brake pressure to drive the other piston out.
Remove the seals, re-install the piston and tie wrap it in place.
Remove tie wrap on other piston and use air or brake pressure to drive it out.
Like Marty said, watch where your fingers are.
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
To get the majority out I use a small tooth brush and brake cleaner to scrub around the pistons before popping them out.
Hooligan gave me his tip 10 years ago and it works like a charm. For a Texan, he's an astute fellow........
Quote from: racerrad8 on January 18, 2017, 11:19:03 AM
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. :-)
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.
Quote from: fjbiker84 on January 18, 2017, 07:28:34 PM
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.
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.
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.
Quote from: Charlie-brm on January 19, 2017, 02:54:03 PM
This is more fun than an oil thread :)
And more likely to produce useful information. :biggrin:
Noel
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,,,,,
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 :Facepalm: