Rehabbing calipers and EBC front rotor symmetry

[97tiger885]

The stuff to redo the caliper has arrived.  I have the caliper on the work table and the pistons removed.  What do I need to do other than remove the old seals and put in the new seals?  The only recommendation I had was to use a dental pick to clean any corrosion from the seats for the seals.  Do the seats for the seals or the pistons get greased or need any prep prior to installation?  And where do I buy a dental pick or its equivalent?

The EBC rotors are on.  I have put on two LH rotors as they were the only rotors I could get.  As far as I can tell, these rotors are not dished.  Is there an inside and an outside or can you mount them as you please?

[Mustang]

need pics of rotor to make a determination ................

try wal mart for a dental pick or in the sporting goods at walmart for a few bucks they have a gun cleaning package that has some nylon brushes and a nylon dental pick in it .

but for that matter a paper clip will work .......

[rybes]

thas about right. make sure the grooves were the seals sit are as spotless as you can get em.dental pick will work but be careful not to scratch the piston bore with it. you can either use some barke fluid to lube the pistons and seals with before ya put it back tgeva. works but messy or you can get yaself some of this stuff

http://www.ebay.co.uk/itm/400086766651? ... 1423.l2649

id go the grease personally and make sure evrythin is spotless. if not, pistons can jam up cos of crap and seize ya caliper.dont ask me how i know  :oops:

[NeilD]

once stripped down I follow pretty much as above.. you may be suprised how much crud you can scrape out of the grooves... I use a dental pick, then give the bare caliper a good scrub in hot water with a toothbrush, a little red brake grease put in the grooves followed by the seals, which i've soaked in brake fluid...

[97tiger885]

It turns out the new brake pistons are so expensive because they come with seals. (I plan to see if Grainger offers these seals at a better price.) I decided to rebuild both right side calipers.  I cleaned the grooves the best I could with a very small screwdriver.  There wasn't any corrosion but there was some stuck-on remnants of the seal.  I used brake fluid as a lubricant.  Caliper one-the front-was fine.  I remounted it and it seems to be working.

Caliper two-the rear-is not fine.  I tested the cylinders before installing the seals using brake fluid to lubricate the cylinder and piston. One cylinder was no problem.  The piston slid in and out with little effort.  The other cylinder is a big problem.  Even with lubrication, it goes in a small distance and hangs up.  If you try to force it, the piston becomes stuck    (the piston is hanging up on the bottom of the second groove or soon thereafter) and requires a lot of force (as in putting the caliper back on, rebleeding and using the brake) to remove.  This is without the seals in.  I don't see any corrosion on the cylinder walls and I have done some cleaning with scotchbrite type sponge..  

What is the problem...dirt on the cylinder wall, deformation of the cylinder, damage to the groove edge...? I read one post which recommended using 1600 grit sandpaper on the cylinder wall if the piston was hanging before seal installation.  Do I gently sand?  If so, what grit, wet or dry?   Is this something a machine shop could deal with better?  

Advice greatly appreciated.

[rybes]

have a look at the seal groove and see if theres a lil lip that might be catchin it. run ya finger nail up the bore of the caliper. if it stops before it falls into the groove, theres a lip,remeber to do that all the way round the groove. if theres a lip be careful and use a small sharp blade to scrape it away DO NOT score the cylinder. personally id stay away from puttin any kind of sand paper in the bore. if theres no groove, get ya piston checked with a very accurate vernier or micrometer to make sure its round. another way would be to try the fittin piston in that bore. if it works, ya pistons out of shape. i cant see that the bore in the caliper would loose its shape but if it has ya lookin at a new caliper.

[rf9rider]

I`ve always cleaned up brake pistons with metal polish and a rag.
I wouldn`t use sandpaper as i reckon it would take the coating off and make things worse?

[NeilD]

as Rybes says, does the same happen when you swap pistons over? shouldnt be that tight with no seals in there..  :?

[97tiger885]

have a look at the seal groove and see if theres a lil lip that might be catchin it. run ya finger nail up the bore of the caliper. if it stops before it falls into the groove, theres a lip,remeber to do that all the way round the groove. if theres a lip be careful and use a small sharp blade to scrape it away DO NOT score the cylinder.

I will do this.  I hope this is it.

if theres no groove, get ya piston checked with a very accurate vernier or micrometer to make sure its round. another way would be to try the fittin piston in that bore. if it works, ya pistons out of shape.

It isn't the pistons.  The same thing happens with different pistons.  One cylinder is ok; one is not.

i cant see that the bore in the caliper would loose its shape but if it has ya lookin at a new caliper.

It is either a lip, a piston or shape change.  I know it isn't the pistons.  

personally id stay away from puttin any kind of sand paper in the bore

If it isn't a lip or the pistons, how much worse can I make it by trying to sand?   The bore is no good.  Sanding either fixes it or makes it worse.  The caliper isn't any good as it is.

[Mustang]

can't hurt to try a wheel cylinder hone at this point , ya know the kind with three stones that you put in a hand drill and let it rip , I'd try it .
go easy just until the piston moves like the good side .
use lots of oil and or brake fluid for a good cutting action

[rybes]

good point mustang. i forgot all about them lil handy gadgets   must remeber to buy one for justin. justin case, do ya know him  :lol:

[97tiger885]

can't hurt to try a wheel cylinder hone at this point , ya know the kind with three stones that you put in a hand drill and let it rip , I'd try it . go easy just until the piston moves like the good side .
use lots of oil and or brake fluid for a good cutting action

A wheel cylinder hone?...that is a new one one me.  There was no lip around the groove, so here is what I did:

 1.  I washed the caliper in a tub of warm water with dish detergent;
 2.  I took a small screwdriver and cleaned out the grooves for the seals;
 3.  I used contact cleaner on the cylinder bore;
 4.  I rewashed the caliper in the water;
 5.  I used a Sharpie Fine Point (a chisel point would have been better) to mark the cylinder bore around and below the bottom lip of the second groove;
 6.  I pushed the piston into the bore until it got lightly stuck,  rotated it several times and removed it,
 7.  I used 600 grit sandpaper on the high spots as shown where the marker was rubbed off;
 8.  I used contact cleaner to remove the rest of the marker;
 9.  I washed the caliper in the tub of water to remove any grit;
10. I retested the piston to see if it fit;
11. If it didn't fit, I went back to step 5. I repeated until the piston fit properly;
12. I washed the caliper thoroughly, blew air through it and left it overnight to dry;
13. I covered the seals with brake fluid, installed the seals, covered the pistons and cylinder bores with brake fluid, pushed in the pistons , covered the posts of the slide with brake fluid, pushed in the slide and installed the new pads.

Initial testing is good (15 miles).  No binding.  We will see if problems develop with more use.  

That leaves the brake strut problem.  Wednesday I deliver the mc to a local machine shop to deal with the oversized hole for the brake strut.  (The bushing Mustang made shows the hole to have worn to a larger size.  I now have it shimmed with aluminum flashing but that doesn't seem a permanent solution.)   Today, the shop did a quick measure and found the hole to be about 1/1000 inch out of round which the machinist thought was not too bad.  The best course of action is to remove the swing arm and put it on a machine to make an accurate hole, but, of course, I have no desire to remove the swing arm.  (I haven't done that yet and I rather not learn now.)  So, I am going to have the machinist hone the hole by  hand, make a bushing to fit and have it pressed in.  There is a good chance that will fix the problem.  If not, I will have to remove the swing arm and get it done properly.

I am glad this is being done in November since I have no heat in the building I use as a work space.  Temps are 55/35 F here.

[97tiger885]

good point mustang. i forgot all about them lil handy gadgets   must remeber to buy one for justin. justin case, do ya know him  :lol:

In the US, Justin Case is well-known as a spokesperson in television ads for SafeAuto, a low-budget auto insurance company.  

[rybes]

glad ya got ya caliper fixed  :D  as for ya bushin, what ya gettin done should fix it nicely. just make sure he makes the new bush out of stainless and that will be that. if he can ream the hole by hand you shouldnt have to remove the swingarm for him to do the job.

[97tiger885]

glad ya got ya caliper fixed  :D  as for ya bushin, what ya gettin done should fix it nicely. just make sure he makes the new bush out of stainless and that will be that. if he can ream the hole by hand you shouldnt have to remove the swingarm for him to do the job.

The shop did the job yesterday.  Total cost was US$20 (14.8 Euros, 12.7 Pounds) plus 2 miles (3.2 kilometers) of walking.  The mc is now inspection ready.  I still have to put the footpeg/sidecase brackets back on. After that, I should be ready to roll.  Thanks for all of the help.  My bar debt at Mustang's Bar, Grill and Motorcycle Repair is starting to build up.  I will need to pay that off in the near future.