O-Ring Conversion - Brake Calipers

[Joe L.]

Re: O-Ring Conversion - Brake Calipers

I've had to do "hybrids" when repairing only 1 caliper or when working on a car in stages. To date I've never had an issue doing so.

Patrick

Patrick-----


Well, maybe I'm overly cautious or "persnickety", but I wouldn't do it.

[Michael G.]

Re: O-Ring Conversion - Brake Calipers

Roger,

One other company to consider would be Lone Star Caliper in the Dallas area.

http://www.lonestarcaliper.com/

[Patrick H.]

Re: O-Ring Conversion - Brake Calipers

Patrick-----


Well, maybe I'm overly cautious or "persnickety", but I wouldn't do it.

You do what you have to when repairing a car.

[Roger D.]

Re: O-Ring Conversion - Brake Calipers

Thanks Michael, yes Lone Star Caliper is in Canton just east of Dallas. Looks like they are wholesale only. Have you bought from them being just an individual? That's why I didn't consider them as a source.

[Bill C.]

Re: O-Ring Conversion - Brake Calipers

All the original caliper pistons I have seen have a good radius machined at the lower leading edge, I would think that would allow for fluid movement even if piston was bottomed, as the fluid inlet to the bore is right at the bottom of the bore edge, usually there is actually a groove created into the bottom from the drilling breaking thru, the pistons for sure must go down at least flush with the caliper face.
To compound the issue, if you come across an early caliper core that was used for the first design pistons, then usually the "stand off" that was in the center of the bore was also machined down.
If it was not, or not all the way, the GM pistons clear it just fine, the new O ring design pistons do not, they are flat on the bottom and do not use springs behind them and will stop the new pistons from seating. The original spring behind the piston design was to keep the pistons up against the back of the pad/rotor so you have "instant" contact when applying your brakes.
This is why the O ring design sometimes will solve air pumping into your system as once the rotor runout pushes the pistons back, they stay there until you hit the brakes again, this is how our everyday car calipers operate.
With the spring behind the piston, as long as there is zero runout on the rotor, its great for the "instant" application as there is no delay in pad to rotor contact. As minimal as that may be, its a better design for racing/track use.
For our everyday use, horrible if you do have rotor run out as then as the rotor turns and "wobbles" do to the run out, as one side leans away from the inner pad, it allows the pistons behind it to move out, and the other side is pushing the pad and pistons back down, when your driving along with that rotor "wobbling" or oscillating like that it creates that dreaded air pumping and air will get pulled right into the fluid past the lip seals on the original design pistons. You quickly loose the brakes and bleed again, and quickly loose your brakes.............
But not with the pistons without the springs as it only takes on turn of the rotor to push the pistons back and then they stay there.
It is a win -win for the everyday driver to use the new oring design pistons and oring seals, and eliminating the springs behind the pistons.
I do agree that it may not be a good idea to mix designs, especially on the same end of the car.
Each car would certainly be different depending on the amount of rotor run out it has, but in theory if say, on the front of the car one wheel had quite a bit of run out and the oring design caliper was used, and the other side had the original design, upon application of the brakes the side with the original design is going to apply pressure to its rotor first, as the oring design side with the rotor runout pistons need to travel the amount of the runout, times all 4 pistons in fluid volume.
How much delay will that realistically create? I am not sure, it would depend on the car. But on the fronts especially it could create a real "pull" to the side that hits first. It would balance quickly yes but at speed, if its a real pull, I do not want it. Could be unnerving.
I would think if one mixed the two designs just between the front and back it would be less of a potential issue. It may affect bias.
One could also of course be certain all 4 rotors have zero runout and then its not an issue, but the real world is different.
So just as a rule, I would avoid mixing the two designs.

[Patrick H.]

Re: O-Ring Conversion - Brake Calipers

Thanks Michael, yes Lone Star Caliper is in Canton just east of Dallas. Looks like they are wholesale only. Have you bought from them being just an individual? That's why I didn't consider them as a source.

They very much sell retail, and I have purchased from them.
I do not think (?) that they do the O-ring style, however.

[Steven S.]

Re: O-Ring Conversion - Brake Calipers

Lonestar does offer o-ring calipers all except for 1st design which they only offer the original lip seal design. Lonestars website indicated wholesale only and I've only ever purchased from them at the Carlisle swap meets, but I have a feeling an individual could purchase from them if you just called them up.

Steve

[Joe L.]

Re: O-Ring Conversion - Brake Calipers

Lonestar does offer o-ring calipers all except for 1st design which they only offer the original lip seal design. Lonestars website indicated wholesale only and I've only ever purchased from them at the Carlisle swap meets, but I have a feeling an individual could purchase from them if you just called them up.

Steve

Steve----

Yes, from what I've experienced, their web-site makes it virtually impossible for non-wholesale customers to order. However, I do think that thy otherwise sell to individual customers.

[Patrick H.]

Re: O-Ring Conversion - Brake Calipers

Bill,

when converting a caliper from lip seals to o-rings myself, I've left the springs in place behind the pistons. No, it's not "needed" but according Vette Brakes and others it won't hurt anything either. So, no issue with "delay" noted here.

Patrick

[Joe L.]

Re: O-Ring Conversion - Brake Calipers

Lonestar does offer o-ring calipers all except for 1st design which they only offer the original lip seal design. Lonestars website indicated wholesale only and I've only ever purchased from them at the Carlisle swap meets, but I have a feeling an individual could purchase from them if you just called them up.

Steve

Steve----

In order to offer an o-ring design piston for 1st design calipers (i.e. all 1965-E67), there would have to be manufactured a special piston designed for o-ring seals, but with the 1st design piston guides also included. I don't even know if this could be done. However, even if it could be done, I would expect that the market demand would not be enough to justify the tooling cost for such pistons. By now, most 1st design calipers have been converted to 2nd design, anyway, by machining out the cast-in piston guides. The available o-ring pistons can be used in 1st design calipers which have been so-converted, though.

[Steven S.]

Re: O-Ring Conversion - Brake Calipers

Joe, VB&P allegedly offers o-ring 1st design, so they must be machined the way you described.

While we are on the subject, did the 1st design calipers originally use an insulator style piston? The reason I ask is my 1st design set I got from Lonestar uses lip seal insulator pistons, which is the only option for the 1st design calipers, so I just was curious if that was how they were equipped originally.

Thanks,
Steve

[Joe L.]

Re: O-Ring Conversion - Brake Calipers

Joe, VB&P allegedly offers o-ring 1st design, so they must be machined the way you described.

While we are on the subject, did the 1st design calipers originally use an insulator style piston? The reason I ask is my 1st design set I got from Lonestar uses lip seal insulator pistons, which is the only option for the 1st design calipers, so I just was curious if that was how they were equipped originally.

Thanks,
Steve

Steve----

All 1st design pistons (used from 1965-E67) were equipped with insulators. Regardless of brake system, standard, J-50, or J-56, the pistons were the same. For 2nd design pistons, only the J-56 used insulators and these were different than the 1st design insulators. Among other things, they were much thicker (and, the piston consequently thinner).

It's possible that VB&P makes an o-ring type first design piston. I was unaware of it, but it's possible. Still seems strange, though, considering the size of the market. If they were talking about calipers that have the piston guides machined out, that effectively converts the 1st design calipers to 2nd design. So, if they say they have an o-ring piston for 1st design, I would think that would include the guided pistons.

[Steven S.]

Re: O-Ring Conversion - Brake Calipers

Joe, thanks for the explaination on the pistons.

Here is VB&P's o-ring set...

http://www.vbandp.com/detail.aspx?ID=282

And here is their lip seal set...

http://www.vbandp.com/detail.aspx?ID=281

It's a generic picture and the description doesn't realy tell much, but I didn't want you to think I was making it up

It wonders me what pistons the lip seal kit uses, I bet it's the second and third design piston and they are machined out like you described, as the price doesn't reflect an obviously more expensive piston.

Steve

[Joe L.]

Re: O-Ring Conversion - Brake Calipers

Joe, thanks for the explaination on the pistons.

Here is VB&P's o-ring set...

http://www.vbandp.com/detail.aspx?ID=282

And here is their lip seal set...

http://www.vbandp.com/detail.aspx?ID=281

It's a generic picture and the description doesn't realy tell much, but I didn't want you to think I was making it up

It wonders me what pistons the lip seal kit uses, I bet it's the second and third design piston and they are machined out like you described, as the price doesn't reflect an obviously more expensive piston.

Steve

Steve-----

I'm not sure what they mean. However, I perused their brake caliper components section. There, they list no 1st design, o-ring type piston. They do list 1st design pistons which use original-type lip seals, but none for 1st design with o-rings. I expect now that what they are talking about with respect to 1st design o-ring calipers is 1st design converted to 2nd design. In that case, the only thing "1st design" about the calipers is the casting numbers.

[Steven S.]

Re: O-Ring Conversion - Brake Calipers

Joe, I believe you got it right. Thanks for your input on the subject!

Steve