Anyone have any Brake Questions?

[manOwar]

What is the standard or the rule for reservoir sizing?

[OG_Racing]

What is the standard or the rule for reservoir sizing?

Excellent question. there isn't one. It all comes down to what the manufacture of the MC recommends. Iv'e seen Reservoirs being close to 1/2 gallon (F&R brake +clutch) . The old AMC eagles' clutch reservoir is literally an enlarged 6"x.25" tube. so contact your MC's manufacture for correct resistor sizing.

[CTX-SLPR]

Generic question about rotor to bearing relationship. How far can you change the relationship on modern sealed hubs and not get into trouble?

Thanks,

[OG_Racing]

Generic question about rotor to bearing relationship. How far can you change the relationship on modern sealed hubs and not get into trouble?

Thanks,

you want that rotor dead center between the bearings. any offset in any direction will shorten the life of the hub. Reference to that analogy i posted earlier. with a 1000hp car you can brake 4-5 times faster then your acceleration. so think of 4000hp backwards, being put onto your suspension components. your going to want to make sure the rotors are centered for the bearings to live.

[CTX-SLPR]

you want that rotor dead center between the bearings. any offset in any direction will shorten the life of the hub. Reference to that analogy i posted earlier. with a 1000hp car you can brake 4-5 times faster then your acceleration. so think of 4000hp backwards, being put onto your suspension components. your going to want to make sure the rotors are centered for the bearings to live.

Understood. I assume that the OEMs have done that from the factory so using a given hub and rotor combination should keep things inline.

Follow on question. If you keep the rotors in the right place axially, keep the same calipers but upgrade the rotor diameter, is there a limit to how much bigger a caliper will swallow?

Example: I have calipers (OEM fixed 4 piston) designed for a 300mm rotor, if I wanted to put them on a 350mm rotor (that is in the right spot) have I gone too far?

Thanks again for fielding questions from the masses!

[minendrews68]

ok I'll try to do that this weekend. Yeah, it's got me stumped. with the clevis loose from the pedal, I would think there should be some play there. It doesn't move maybe 1/4" in and out. Now I'm wondering if maybe the pin may not be situated in the booster correctly.

Well, got my problem figured out today. (actually the guys at Inline had me try this). I went for a spin this afternoon and sure enough the breaks locked up. Inline said if this happens to go under the hood and loosen the MC from the booster. I did that and it released the pressure. The problem was that I have the wrong pin between the MC and the booster. They said I could either take the long pin out and replace with the shorter one, or just shim between the MC and booster. Thanks everyone for your help.

[RobNoLimit]

Well, got my problem figured out today. (actually the guys at Inline had me try this). I went for a spin this afternoon and sure enough the breaks locked up. Inline said if this happens to go under the hood and loosen the MC from the booster. I did that and it released the pressure. The problem was that I have the wrong pin between the MC and the booster. They said I could either take the long pin out and replace with the shorter one, or just shim between the MC and booster. Thanks everyone for your help.

this is pretty common with aftermarket boosters and masters. Normal (OE) masters don't have this issue, the piston is machined to fit a certain booster. The mis-match is usually only .020" to .040". You can put the pin in a 1/2" drill and spin it against a grinder or sander, and cut a bit off of the length. The fit should be a '0' lash. No slop, no pre-load. Glad you found the problem.

[OG_Racing]

Understood. I assume that the OEMs have done that from the factory so using a given hub and rotor combination should keep things inline.

Follow on question. If you keep the rotors in the right place axially, keep the same calipers but upgrade the rotor diameter, is there a limit to how much bigger a caliper will swallow?

Example: I have calipers (OEM fixed 4 piston) designed for a 300mm rotor, if I wanted to put them on a 350mm rotor (that is in the right spot) have I gone too far?

Thanks again for fielding questions from the masses!

YEP, When a caliper is engineered The Outter rotor diameter is taken into consideration. chances are... if you did fit a caliper engineered for a 300mm rotor, on to a 350mm rotor, the brake pad won't fit on to the rotor. the very top of the pad will overhang.
For your set up i don't know what caliper you have. best is to call the manufacture and ask what is the maximum rotor allowed, you might get lucky.

[CTX-SLPR]

I have Sumitomo R32 GTR brake calipers, 4 fixed 40.4mm pistons, cast aluminum. Original application was 296x32mm disc I have them on that size disc now (73-88 Chevy C10 HD rotors) and it's unbelievable how close they fit to both the OD and the ID of the rotor annulus. Just barely clears the inside of 15in wheels designed for the early iron fixed caliper brakes on a 68 Riviera. Considering how much they were to get originally I'm first attempting to continue to reuse them as I upgrade the stopping ability on a 2 ton car. Was planning a 350x32mm rotor off of a 2011-2016 Jeep Grand Cherokee since it shares the same 5x5 bolt pattern.

[72RS]

I have one for you Doing a rear disc conversion on my 72 Camaro using the Wilwood kit with parking brake. How does the paking brake kit hook up at the front of the car? I undrstand how it hooks up at the rear brakes but where does it go from there. The instructions are not very good. I am hoping i tie into my factory cable that is attached to e-brake pedal in the car where it comes through the floorboard.

[OG_Racing]

you'll need to send me pictures. i don't have any reference with parking brakes.

[72RS]

you'll need to send me pictures. i don't have any reference with parking brakes.

http://www.wilwood.com/Pdf/DataSheets/ds646.pdf

This is the kit. Like I say the rear is pretty self explanatory...just not sure how it would all tie in at the front. I can get you a pic of the underside of the car when I get home.

[OG_Racing]

i don't really do parking brakes, sorry. ive removed more parking brakes then I've repaired. just dead weight on a race car.

[Elviscamino]

I just found this today. Great thread, thanks for posting it.

[nats68]

OK Johnny C I've got a problem that maybe you can help me solve.
I've got a 1968 Camaro with Wilwood forged dynalite brakes. All new brake lines from Right Stuff.
I can't get fluid to the rear brakes.
I disconnected the flex line over the rear end and attached a pressure bleeder on the end of the hard line. I was able to suck fluid from the master cylinder. I then went to the brake cylinder and pushed fluid through the flex line, when it was disconnected.
When I connect the hose to hard line it won't let fluid pass that fitting. Both the hose and hardline are from Right Stuff and appear to be correct, as far as the flare and inverted flare. I also tried a standard rubber line and it did the same thing. I figured the flared end was bad so I cut the line and flared it again. It did the same thing.
I'm lost as to what the problem could be.
Thanks for any help you can give.

[JustJohn]

What is the source of the persistent myth that converting to rear disc brakes requires larger OD brake lines? I've seen it so many times it made me wonder about basic hydraulic circuit theory myself.

[Ducati68]

I'm installing a disc break conversion on the 68 with staggard shocks. I'm using the right stuff detailing kit. How hard is it to install the e-brake cables to the original cable coming out the fire wall?

[OG_Racing]

What is the source of the persistent myth that converting to rear disc brakes requires larger OD brake lines? I've seen it so many times it made me wonder about basic hydraulic circuit theory myself.

i've never heard of that. everything I've run has been a -3an fitting. that includes race cars.

[OG_Racing]

I'm installing a disc break conversion on the 68 with staggard shocks. I'm using the right stuff detailing kit. How hard is it to install the e-brake cables to the original cable coming out the fire wall?

i don't really do parking brakes, sorry. ive removed more parking brakes then I've repaired. just dead weight on a race car.

[OG_Racing]

OK Johnny C I've got a problem that maybe you can help me solve.
I've got a 1968 Camaro with Wilwood forged dynalite brakes. All new brake lines from Right Stuff.
I can't get fluid to the rear brakes.
I disconnected the flex line over the rear end and attached a pressure bleeder on the end of the hard line. I was able to suck fluid from the master cylinder. I then went to the brake cylinder and pushed fluid through the flex line, when it was disconnected.
When I connect the hose to hard line it won't let fluid pass that fitting. Both the hose and hardline are from Right Stuff and appear to be correct, as far as the flare and inverted flare. I also tried a standard rubber line and it did the same thing. I figured the flared end was bad so I cut the line and flared it again. It did the same thing.
I'm lost as to what the problem could be.
Thanks for any help you can give.

what nipple are you turning? wilwoods come with bleeders that take a 1/4" wrench. if your turning the 7/16 bolt it won't bleed.