DansYellow66

I tore a rear brake caliper down today because I was getting the characteristic trail of fluid down the inside of the tire. After removal I think it was actually a connection or bleeder leaking as the piston areas seemed dry. But, I had the rebuild kit so I decided to replace the seals anyway in this previously sleeved calipers.

Question - anyone have any handy tips for starting the piston seal lip past the tip of the bore to prevent damaging it? One Corvette repair manual I have said to use a piston ring compressor ???? Probably something like that exists for small gas engines but finding one sounds tough. The GM manual said just use care and nudge the edge of the seal past the top of the bore with a screwdriver blade. This is do-able I suppose, but seems a bit Bubba. Anyone have any better ideas/tips they want to pass along.

Thanks

Powershift

Dan:

CSSB Inc sells the seal compressor/installer. At least they did a few years ago when I bought one.

I have done these before and simply used a small screwdriver and a very small diameter wooden dowel (1/8 inch) to assist installation. Lube everything good in brake fluid and take your time.

Larry

EDIT: http://www.cssbinc.com/1965-82corvet...ationtool.aspx

DansYellow66

Larry - what's CSSB - not recognizing it immediately.

I guess a popcycle stick would work OKl to push the seal past the lip. I keep a large supply of them in the garage.

Edit - I see you added a link on CSSB. Thanks.

Dan

R66

I lube up a 1/8" wide feeler gauge and carefully run it around the lip seal as I am applying slight pressure. You can feel if it is getting resistance - back off and go the other way. A paper clip also works with less chance of cutting the lip seal
If you are putting in O-rings, just push like hhhhhlll.
The big problem is holding all of the pistons in while doing this. I have a small C-clamp and thing plate to do this.

redvetracr

I`m using a lubed up .020-.025 feeler gauge and for the dust boots a socket or a PVC (plastic) cap from the big box hardware store

DansYellow66

Thanks - I'm kind of imagining that trying to hold the piston steady against the spring pressure while trying to work the lip in might be difficult - but guess I need to give it a try.

I also thought about taking a strip of plastic from a blister pack and make a funnel/guide/compressor by rolling it into a cylinder and see if it would work in place of a real ring compressor. I could hold it's shape with a hose clamp around the outside of it. But the ring in the outer seal may interfere with it's easy removal.

I'll figure something out.

ILBMF

You can cut a piece of a beer or soda can and make a circular sleeve. Wear gloves and lubricate everything with brake fluid before pushing the piston in. I repair electric forklifts for a living and have done this many times over the years on some hydraulic cylinders.

R66

Actually, I have done that putting rings in a small lawn mower engine. It works too, but I used a plastic butter container so as not to scratch the cylinders. Sounds like you have it mastered.

ILBMF

An aluminum can won't scratch the stainless steel sleeve. The thinner the can material the better to avoid tight fit when sliding the piston in.

R66, every time I think I have my job mastered something else comes along and taxes my brain. I've been doing it for 33 years and I learn something almost every day.

wmf62

I always poked the lip in with a feeler gauge...
Bill

Powershift

I guess for Dan's situation the good news is there are MANY different ways to successfully accomplish his task:

1. Buy a special installation sleeve made for the job.

2. Make a special installation sleeve from common materials.

3. Don't buy or make anything, just use a few typical garage/toolbox tools.



Larry

suntreemcanic

I have a roll of .005 brass shim stock (available from NAPA). Cut off a piece that will wrap around the piston with a little overlap and extend about a inch below the piston, lube the shim stock, use your hand as an outside reinforcement for the brass and push the piston into the caliper. Remove the shim stock and use it for the next piston.

ILBMF

And the brass won't scratch stainless steel either

R66

ILBMF, I agree, the day you quit learning is the day you die.
I, like you, find better ways of doing things (as well as the worst ways) almost every time I do something. That's the fun of doing it yourself.

Almost anything will work as long as it does not cut the lip seal. I think we all agree on that. Actually the feeler gauge requires more attention to detail when running in the seal as you can cut the lip or fold it back. A paper clip has no sharp edges. But, any material can be rounded to prevent it from cutting the seal. I think they are all great ideas.

Tampa Jerry

I bought the install kit decades ago. Ask any Corvette brake rebuilder to sell you one front and one rear stainless steel sleeve they use when adding stainless steel inserts to a caliper. I add brake fluid to the sleeve, insert the piston into the sleeve. Next, put the sleeve on top of the caliper bore and push down. It is like a small version of a ring compressor that you use on an engine. The kit also came with a two plastic pucks that that are used to seat the dust ring without distorting the outer metal ring. You could also use a large socket for this step. Jerry

DansYellow66

The .020 flat feeler gage won out. I tried a couple things but the feeler gage by far worked easiest. Turned out to be one of those first time things that I was over-thinking and turned out much easier than I thought.

Well - except for the one piston I seated and then spotted the spring sitting on the work bench still. I thought it went on a little easier than the others.

babbah

POPSICLE stick works fine on lip seals.
I'm wondering why you didn't use the ORing Seals instead? They work perfectly and no
leaks.

wmf62

the biggest potential problem for me seemed to be keeping all 4 pistons in while reassembling and reinstalling....

Bill

DUB

I knew someone would comment on O ring seals....which is fine by me....

It is often a misconception...O ring sealed calipers DO leak...and actually can eat/erode/wear a groove in the stainless steel sleeve just like a lipped seal....because I have replaced leaking calipers with O ring seals.

And I am not writing this because I am the guy who makes only lipped seals for Corvette calipers and do not want people to use O ring seals. I am a guy who works on this stuff and I see things that many people with only one Corvette may never see.

To each his/her own. Use what you want..I know what I will only use and sell in my shop.

DUB

R66

Great

I am hoping not to have to do it again for a while.

I think Bill wants to know how you held the pistons in while you put the caliper back on.

In fear of starting another war, I use two pieces of thin aluminum and a couple of small C-clamps, but am always willing to learn a better way before I have to do it again.

P.S. you'll find more springs and parts missing as you get older. I reassembled the M20 Muncie and forgot to torque the input nut. Woke up at 2 a.m. thinking of it and disassembled the front retainer to torque it. Had to get it before the blue Thread locker set.