C5 Corvette MC

[TnBlkC230WZ]

I've installed a set of Wilwood front brakes with 4.04 inches of piston area and now I have very little pedal travel. I'm going to replace my C2 1.125 inch Corvett MC with a C5 1 inch MC. I'm also thinking about installing a Wilwood distribution block/proportioning valve.

My questions are

1. How do I adapt the 10MM inverted flare fittings to the 3/8 inverted flare on the Wilwood proportioning valve?

2. Will it bolt directly to my 71 Nova vacuum booster?

3. Am I better off using a 98 - 02 Camaro booster and 1 inch MC? The lines exit on the left, but I can work with that; however, it is still has 12MM fittings.

[Apogee]

1. What 10mm inverted flare fittings are you referring?

2. No, a late model C5/C6/LS1 master cylinder will not bolt onto your OE booster since it has a long pushrod and those master cylinders have shallow pushrod holes. A 1968-1976 C3 Corvette master cylinder with a 1" bore (manual brakes) should however be a direct bolt-on solution for a 1" bore in your application.

3. I don't typically recommend running the C5 master cylinders due to the metric ports and overall cost of the units. You can pick them up reasonably cheap used, but I prefer new myself when it comes to MC's. That said, the 1997 had (2) M12x1.0 ISO bubble flare outlet ports and the 1998-2004 had (1) M12x1.0 and (1) M12x1.5 ISO bubble flares. Finding tube nuts for the M12x1.5 can be a bit of a chore in my experience, especially since a lot of the aftermarket tube nuts interfere with the tapered sealing surface prior to sealing and require machining to work. The 1998-2002 LS1 F-body MC has (1) M11x1.5 and (1) M12x1.0 ISO bubble flare outlet ports, so tube nuts are more readily available, but there are better options IMHO.

Tobin
KORE3

[TnBlkC230WZ]

1. What 10mm inverted flare fittings are you referring?

2. No, a late model C5/C6/LS1 master cylinder will not bolt onto your OE booster since it has a long pushrod and those master cylinders have shallow pushrod holes. A 1968-1976 C3 Corvette master cylinder with a 1" bore (manual brakes) should however be a direct bolt-on solution for a 1" bore in your application.

3. I don't typically recommend running the C5 master cylinders due to the metric ports and overall cost of the units. You can pick them up reasonably cheap used, but I prefer new myself when it comes to MC's. That said, the 1997 had (2) M12x1.0 ISO bubble flare outlet ports and the 1998-2004 had (1) M12x1.0 and (1) M12x1.5 ISO bubble flares. Finding tube nuts for the M12x1.5 can be a bit of a chore in my experience, especially since a lot of the aftermarket tube nuts interfere with the tapered sealing surface prior to sealing and require machining to work. The 1998-2002 LS1 F-body MC hanfs (1) M11x1.5 and (1) M12x1.0 ISO bubble flare outlet ports, so tube nuts are more readily available, but there are better options IMHO.

Tobin
KORE3

Thanks Tobin. I had a couple of typos. I ment 12 mm fittings and I currently have a C3 MC. Maybe I should just stay with the C3.

I was hoping to find an aluminum MC with a resevoir that is level at the top. Are the Wilwood aluminum MCs pretty good? Do you offer an aluminum solution?

[Apogee]

It sounds like you have a power C3 master cylinder since it has a 1-1/8" bore, however the 1" bore manual version should be a direct interchange if you're only looking to decrease the bore size.

Yes, the Wilwood aluminum MC's are very good units for the money and should be compatible with your booster as they're somewhat more universal than most OE units. We have begun to stock these as well as the #260-11179 distribution blocks with the adjustable proportioning valves and pressure switch as well.



Alternatively, if you don't mind swapping boosters, you would add some shallow pushrod hole MC options as well. Do you know what your vacuum levels are at idle? It's possible that you might be better off going manual than sticking with vacuum assist...now would be the time since you definitely need to change master cylinders.

Tobin
KORE3

[TnBlkC230WZ]

It sounds like you have a power C3 master cylinder since it has a 1-1/8" bore, however the 1" bore manual version should be a direct interchange if you're only looking to decrease the bore size.

Yes, the Wilwood aluminum MC's are very good units for the money and should be compatible with your booster as they're somewhat more universal than most OE units. We have begun to stock these as well as the #260-11179 distribution blocks with the adjustable proportioning valves and pressure switch as well.

Alternatively, if you don't mind swapping boosters, you would add some shallow pushrod hole MC options as well. Do you know what your vacuum levels are at idle? It's possible that you might be better off going manual than sticking with vacuum assist...now would be the time since you definitely need to change master cylinders.

Tobin
KORE3

My engine holds 16 lbs of vacuum at idle. I'm open to a new booster, especially a 9 inch. I currently have a Delco 11 inch. Minor fabrication is also doable.

[Twin_Turbo]

pegasus has one of the required fittings to adapt to -3 or -4 lines. The other one they only have the wrong flare (inverted flare), you could epoxy it into the MC. I have done that before, never had a leak. You could also have some flex lines made w/ the 2 different M12 threads on one end and the UN threads on the other side. Did that on the vette.

[TnBlkC230WZ]

That's what I'm looking for. I may still need a new booster. I need to look at it closer.

I like the C5 MC because the resevoir lids are level instead of angled back, it's aluminum and it is easier to hook my bleeder up for changing fluid.

[MrQuick]

That's what I'm looking for. I may still need a new booster. I need to look at it closer.

I like the C5 MC because the resevoir lids are level instead of angled back, it's aluminum and it is easier to hook my bleeder up for changing fluid.

and the lines come out fender side