Rebuilding F4i Calipers - advise?
#1
Senior Member
SuperSport
Thread Starter
Join Date: Jun 2010
Location: Baltimore, Maryland
Posts: 636
Rebuilding F4i Calipers - advise?
I picked up a complete front brake setup from an F4i yesterday for $100, not sure if I got a good deal or not, seems like that's about what they go for on ebay. Looks like the bike they came off was sitting outside it's entire life, all the hardware is rusty, and the calipers themselves are pretty dirty...
I want to clean them up before I install them, and depending how they clean up maybe i'll repaint them. I'm thinking about ordering all new hardware (4 torx/2 Hex bolts each) from Ronayers.com or similar.
I've never rebuilt calipers before, so I wanted to see if anyone here has some tips or advice before I tear everything apart. Should I replace all the piston seals when I take it apart? I haven't decided if it's a good idea or not to split the calipers apart to clean/paint. Whats the best way to get the old paint off? sand/media blasting a bad idea?
any recommendations would be greatly appreciated.
Thanks
I want to clean them up before I install them, and depending how they clean up maybe i'll repaint them. I'm thinking about ordering all new hardware (4 torx/2 Hex bolts each) from Ronayers.com or similar.
I've never rebuilt calipers before, so I wanted to see if anyone here has some tips or advice before I tear everything apart. Should I replace all the piston seals when I take it apart? I haven't decided if it's a good idea or not to split the calipers apart to clean/paint. Whats the best way to get the old paint off? sand/media blasting a bad idea?
any recommendations would be greatly appreciated.
Thanks
#2
If you take it apart replace all seals.. Have a VERY clean, dust, dirt, lint free area. Have lots of clean brake fluid on hand.. Use it as a cleaning agent... everything gets coated well with clean fresh brake fluid before assembly.. Worry about cleaning the excess brake fluid off AFTER the calipers are together.
Yes those are pretty beat.. even the black paint is faded.
Your price is, well a bit high..
for $100 I would have wanted a clean set. But that’s past so no worries.. Just go from here.
IF you find the pistons damaged when you get um apart.. I’d rethink building this set. As it’s going to take some work and $$ to make those nice and useable again.
Yes those are pretty beat.. even the black paint is faded.
Your price is, well a bit high..
for $100 I would have wanted a clean set. But that’s past so no worries.. Just go from here.
IF you find the pistons damaged when you get um apart.. I’d rethink building this set. As it’s going to take some work and $$ to make those nice and useable again.
Last edited by E.Marquez; 08-13-2010 at 12:33 PM.
#3
Senior Member
SuperSport
Thread Starter
Join Date: Jun 2010
Location: Baltimore, Maryland
Posts: 636
Just priced out some parts...
4 - 8x40 Torx
4 - 8x35 Torx
4 - Pin Hangers (Hex)
4 - Piston Seal set #1
4 - Piston Seal set #2
2 - Spring Pad
Comes to $120 on Ronayers. Any other parts i would need? Maybe there is are brake pad kits that come with the pin hangers and spring pad?
4 - 8x40 Torx
4 - 8x35 Torx
4 - Pin Hangers (Hex)
4 - Piston Seal set #1
4 - Piston Seal set #2
2 - Spring Pad
Comes to $120 on Ronayers. Any other parts i would need? Maybe there is are brake pad kits that come with the pin hangers and spring pad?
#4
You may be able to get away with using the original seals. I prefer to replace, but if cost is an issue, you can soak them in water and simple green - do not soak in kerosene or other solvents - kerosene will swell the rubber. You can then soak them in DOT-4, then wipe them off.
There is a way to get the pistons out, but I have had a few shots so maybe later. Use duplicolor caliper paint - nice stuff.
JB
There is a way to get the pistons out, but I have had a few shots so maybe later. Use duplicolor caliper paint - nice stuff.
JB
#5
You may be able to get away with using the original seals. I prefer to replace, but if cost is an issue, you can soak them in water and simple green - do not soak in kerosene or other solvents - kerosene will swell the rubber. You can then soak them in DOT-4, then wipe them off.
Since they were stored still hooked up to the master, the caliper internals may be quite clean...depending on whether the previous owner kept clean fluid in it. But the seals should be replaced regardless.
#6
To get the pistons out , remove all lines , wrap a wrench in a paper towel . Put this in center of caliper and spray compressed air into the orifice your line was attached to . The wrench will provide a stopping point for the pistons . Then you can remove pistons by hand . Replace all seals and crush washers to avoid future leaks and perhaps a accident .
#7
To get the pistons out , remove all lines , wrap a wrench in a paper towel . Put this in center of caliper and spray compressed air into the orifice your line was attached to . The wrench will provide a stopping point for the pistons . Then you can remove pistons by hand . Replace all seals and crush washers to avoid future leaks and perhaps a accident .
#8
With all due respect, don't even think about it. The cost of new piston seals is nothing compared with your life, or crash damage to your bike.
Since they were stored still hooked up to the master, the caliper internals may be quite clean...depending on whether the previous owner kept clean fluid in it. But the seals should be replaced regardless.
Since they were stored still hooked up to the master, the caliper internals may be quite clean...depending on whether the previous owner kept clean fluid in it. But the seals should be replaced regardless.
The alternative is not to rebuild the calipers and have gummed up pistons grinding away at the seals.
#9
This is the way I do it. Clean everything very well and i also use this when reassembling calipers. It works much better than brake fluid for me.
Attachment 9898
Attachment 9898
#11
Well you need to make sure that you don't get anywhere near the piston bores and also you would need to do a very thorough cleaning to make sure you removed all the media from the blasting.
So yes you can do it but you need to be very careful. A good wire brush usually does a fine job on the outer surfaces.
Now cleaning the pistons and the internal parts of the caliper is a whole different story.
So yes you can do it but you need to be very careful. A good wire brush usually does a fine job on the outer surfaces.
Now cleaning the pistons and the internal parts of the caliper is a whole different story.
#12
And make sure you cover the sealing surfaces and openings for the brake lines, where the crush washers seat. Also, don't split the calipers unless you have new o-rings for the crossover. If the bores need cleaning up, use crocus cloth with a sideways motion around the bore, not up and down. Then clean well with brake fluid.
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