500psi T-Bird Calipers

[nvrstuk]

Coming back to volume again... those math #'s seem to point to the mc.

You get the mc # I sent ya?


I believe its a 1996 Chev 1 ton M/C for HB on diesel. 1.25” bore installed 5/23 . Calipers are JB7 application for Chev 1 ton trucks frt & rear. HUGE volume, appr the same as twin caliper SD my friend figured - which is what he's running

Don't use Oriellys house brand but this Part # NMC90032 will cross reference to an AC/Delco or whatever brand.

 

[1973bronco1973]

I use the corvette cast iron master cylinder with 1.125 bore on my 4wheel disc setup with hydro boost. But I use the front port on the mc for the front axle. In the test pic it looked like the front caliper was hooked to the rear port. What effect would swapping those have on performance? I have never done it, but maybe someone has that experience?

 

[Oldtimer]

When pedal travel stops, is pedal against floor, or has master cylinder or hydroboost run out of travel? Which one limits travel?

 

[chuzie]

You get the mc # I sent ya?

Yes, thank you

I use the corvette cast iron master cylinder with 1.125 bore on my 4wheel disc setup with hydro boost. But I use the front port on the mc for the front axle. In the test pic it looked like the front caliper was hooked to the rear port. What effect would swapping those have on performance?

Well, let me tell you what effect it has on performance my friend... it gave me pressure at the caliper!!
WTF?

We entertained this idea early on by came to the consensus that, in theory, it shouldn't matter, so I have some questions to ask CPP tomorrow for sure!

This is a major breakthrough, but I'm not quite ready to say the issue is resolved.

- Need to make sure there's no pressure loss at the rear brakes now, but I've run out of time.

- Only getting 1500psi at the fronts and discovered the 90* fitting on the Mico lever lock finally cracked. Way too many tightening / loosening cycles with this disaster. When pedal travel stops, is pedal against floor, or has master cylinder or hydroboost run out of travel? Which one limits travel?
FWIW- doesn't hit the floor. Definitely stopping via MC or HB.

 

[1973bronco1973]

Sounds like progress! I remember reading a long time ago, and from dirt donk replies that the corvette master can be opposite of how ford plumbed their mc. I hope it works!

 

[ksagis]

This screams more to me of a bad MC with bad seals on one circuit versus the front pot works better. What that it is unclear to me, willing to be folks like @ntsqd, @Apogee, and @nvrstuk have good ideas.

The camaraderie of this forum is great to watch on this thread.

 

[chuzie]

This screams more to me of a bad MC with bad seals on one circuit versus the front pot works better.

1000% agreed

Now that we know I don't need a larger bore, gonna order a 77 Corvette MC.
Won't be going with CPP again though.

No one has anything name brand locally, just house brands.

Guess I'm dead in the water for a few days.

 

[nvrstuk]

Where is the large reservoir in the MC? Towards the frt or the rear?

Larger reservoir is always connected to the front- at least that is the accepted theory. Least I have never seen or heard of the large reservoir on an mc being for the rear brakes when a car has disc brakes up front ONLY, however, the theory being that the larger reservoir always supplies fluid to the axle with disc brakes since as the pads wear the larger reservoir is needed to supply an adequate margin of fluid from the reservoir.

GM and Corvette are different in that the Vette's with 4W discs usually have equal size mc's EVEN tho the fronts wear out faster than the rear due to brake bias.

This is from my limited knowledge and background working at a GM dealership doing brakes (and other stuff) but that doesn't mean I'm right.... never has yet anyway!

I thought you had switched the ports since it had been brought up and discussed, I assumed and was wrong (again). lol

Hopefully you got this Chuzie.

 

[nvrstuk]

1000% agreed

Now that we know I don't need a larger bore, gonna order a 77 Corvette MC.
Won't be going with CPP again though.

No one has anything name brand locally, just house brands.

Guess I'm dead in the water for a few days.

Gotta ask- why go with the rusty, ugly potentially leakage prone mc when upgrades are available?

 

[chuzie]

Where is the large reservoir in the MC? Towards the frt or the rear?

It's a 50/50

Gotta ask- why go with the rusty, ugly potentially leakage prone mc when upgrades are available?

I'm open to suggestions. Haven't clicked the purchase button yet. Rusty + ugly match the rest of my Bronco though

 

[nvrstuk]

Larger bore benefits:

- less pedal stroke

- since you'll have a bit less stroke you can set pedal height so you don't have to lift your foot off the floor as far and reaction time will be better. Pedal height is important

- better pedal feel since it won't be as touchy especially if conditions are slick

- sure look better

- designed for hydroboost (doesn't matter a lot tho).

- last... your choice...


Huge difference in an 1/8" bore when running manual brakes. Either you can't lock up the brakes because the pedal is so hard to push with bore too large (old skool-pre ABS) or you have to pump the pedal quickly 2x to lock them up because of not enough fluid with the bore being undersized.

HB allows you to go slightly over bore size and not have any negative side affects like you would with a manual application. I think the guys that complain about being "sent thru the windshield) use a stock EB bore sized mc with a HB. Definitely overkill and too sensitive a pedal imo.

 

[chuzie]

Larger bore benefits:

- less pedal stroke

- since you'll have a bit less stroke you can set pedal height so you don't have to lift your foot off the floor as far and reaction time will be better. Pedal height is important

- better pedal feel since it won't be as touchy especially if conditions are slick

- sure look better

- designed for hydroboost (doesn't matter a lot tho)

- last... your choice...

I'm totally down with that. Guess I assumed your previous suggestion was based solely on increasing volume and I failed to realize the additional benefits. Will see if one is available locally.

 

[lars]

1000% agreed

Now that we know I don't need a larger bore, gonna order a 77 Corvette MC.
Won't be going with CPP again though.

No one has anything name brand locally, just house brands.

Guess I'm dead in the water for a few days.

PM me your address. I have a Mark Williams (I think) aluminum clone Dodge 1-1/8" master cylinder, ports on drivers side, worked perfectly for years on my Bronco with the exact same front calipers, rear Explorer discs, hydroboost, etc. I went to an utterly completely different front brake setup and couldn't use it anymore. Was working perfectly when removed but should be bench bled before reinstalling. Yours for the taking.

 

[nvrstuk]

Lars is your man!! Plus you know it works!

 

[ksagis]

1000% agreed

Now that we know I don't need a larger bore, gonna order a 77 Corvette MC.
Won't be going with CPP again though.

No one has anything name brand locally, just house brands.

Guess I'm dead in the water for a few days.

you have napa close? This MC is what power brake 1977-1982 C3 Vettes had installed and has shallow MC cup so you could tighten up the gap:

https://www.napaonline.com/en/p/NMCM2300

Here's Autozone equivalent:

https://www.autozone.com/brakes-and...-nm1749/248432_0_0?searchText=master+cylinder

 

[ntsqd]

I'm running the m/c from a '97 F-350 turbo-diesel on Snowball. The pedal is firm, travel is very short, pedal feel is very linear - the best that I've driven in years, and I can lock all of the brakes with two toes.

After one iron m/c developed a rust-ring in it's reservoir I've no interest in iron m/c's any more.

 

[chuzie]

PM me your address. I have a Mark Williams (I think) aluminum clone Dodge 1-1/8" master cylinder...

Love you man for the generous offer, but I'm sweet on the bigger bore now.

you have napa close? This MC is what power brake 1977-1982 C3 Vettes had installed and has shallow MC cup so you could tighten up the gap:

Thanks for the leg work, but I'm gonna try the 1996 C3500 MC instead.

 

[ntsqd]

The ACDelco18M742 is a Ø1.25" bore, but the other ACDelco p/n is a LOT bigger. Too big IMO. I looked because I was looking at the '96 K3500 m/c as a possible for the Wagon as you were posting above.

 

[ksagis]

Be sure to check you hood clearance and the the taller MC will fit. I was looking as some of those and it was tight for me and I have non factory hood.

 

[nvrstuk]

Be sure to check you hood clearance and the the taller MC will fit. I was looking as some of those and it was tight for me and I have non factory hood.

I can measure from the centerline of the mc up to the top of the reservoir tomorrow for ya if you want Chuzie. Make sure it fits. I think the lower profile AstroVan reservoirs fit on it also as another option... I think??? Not even 68% sure tho... lol