Reverting back to stock from t-bird calipers- banjo fitting

[chuzie]

So I'm going back to stock front calipers in an effort to balance my system.

I had to drill my banjos larger for the t-bird caliper conversion. Can I get away with using these same lines for stock calipers or am I asking for a leak?

Just too cheap to buy another set of stainless braided!

 

[spap]

I wouldn't think so, plus it s your brakes. Probably not something you want to fail. Stock lines are not that much. Did you ever try a proportioning valve to correct the brake balance

 

[Apogee]

Please don't...face seals with crush washers should be nominally matched with respect to size, especially considering the potential repercussions of a failure.

 

[chuzie]

Please don't...face seals with crush washers should be nominally matched with respect to size, especially considering the potential repercussions of a failure.

The brake god has spoken.

Ordering new SS braided lines today. Thanks for the input fellas.

 

[Broncobowsher]

Put the drilled brake lines with the calipers and sell as a package deal to someone wanting to go to the T-bird calipers.

 

[73azbronco]

what system are you using besides the Tbird calipers?

 

[chuzie]

Explorer rears. Going to be removing them in favor of s-10 setup

 

[u10072]

Chuzie-- not to sound like an ass but smaller brakes really doesn't make any sense. What symptoms are being presented to think that's a good idea? Just curious???

 

[chuzie]

Because my explorer rears dont work and I am swapping system to one I have seen work extremely well.

Here is my thread from hell regarding explorer issue. http://classicbroncos.com/forums/showthread.php?t=224831

In summary, no one can figure out why they don't work and I am done sinking time and $ into a failed project. Cutting losses and starting from scratch.

The stock bronco calipers will complement the s-10 calipers for 70/30 with a Eldorado mc. Still researching final numbers.

 

[chuzie]

Does anyone have a resource to confirm what bore size the 1992 S-10 p/u 4wd front caliper bore is? I can't find anything online and want to be sure of these numbers before I start ditching parts.

 

[broncnaz]

Actually S10 calipers will be larger So you should get more stopping power. Explorer uses 1 7/8" pistons. S10 2.5in pistons. Probably the only glitch is the S10 needs metric lines.

Stock bronco caliper bores are about 2 7/8" Where the tbird bore is 3.1. You'll probably want to keep the tbird caliper in place.

 

[Broncobowsher]

What size do you want the caliper to be?
http://www.speedwaymotors.com/Search?query=metric caliper&facet=GA_Sema_Part:Disc Brake Calipers

 

[chuzie]

Actually S10 calipers will be larger So you should get more stopping power. Explorer uses 1 7/8" pistons. S10 2.5in pistons. Probably the only glitch is the S10 needs metric lines.

Stock bronco caliper bores are about 2 7/8" Where the tbird bore is 3.1. You'll probably want to keep the tbird caliper in place.

I wish there was an adapter for those metric lines. Gonna have to rework the steel lines on the axle and make a hybrid line.

For some reason I thought the S-10 was smaller but you are absolutely correct, I think I will keep my T-bird calipers. That will put me at 80/20 vs 86/14 with the stock bronco calipers. Then I can tune it down to 70/30 with the adjustable.

What size do you want the caliper to be?
http://www.speedwaymotors.com/Search?query=metric caliper&facet=GA_Sema_Part:Disc Brake Calipers

I am doing the rear disc install Matt Miner published in Bronco Driver a few years ago. It uses GM metric (5.5" hole centers) caliper brackets from AA Mfg, front calipers from a 92 S-10 p/u 4wd, and rotors from a 77 CJ7.

Ideally, I would like to see a 70/30 split without employing an adjustable proportioning valve. I am just not sure I can competently select a caliper from that site you linked to that will fit both the brackets and rotor correctly. In a perfect world, I would like a 2-5/32" bore to achieve 70/30 with the t-bird calipers in the front.

Thanks for the info guys. Gonna do some more research.

 

[Broncobowsher]

That link had 3 different 2" caliper options.
As for doing a copy of someone else's brake job. Are you running the same pads? That makes a difference. Front to rear weight distribution? On a short wheelbase Bronco that is a huge factor. Height of CG? Not position, that is accounted for with front/rear weight distribution. But actual height. The higher the CG, the more the front brakes load up and the rears need less.

Getting good brakes on an EB is tough as no one sets them up the same. Couple more inches of lift, heavy front bumper and remove the spare off the back and the braking forces on the short wheelbase drasticly change. That's before you even get into caliper bore size and pad material.

If you are trying to get a 2-5/32 rear caliper to match the front T-bird, going to a smaller front caliper will require an even smaller rear caliper. Smallest metric caliper I found was only 2" What would you do if you went back to standard front calipers? That really is, what rear caliper would you need in back?

 

[chuzie]

I may use same pads he used. Have to stick the coefficient of friction into the calculator first.

Do most GM brakes use the same bolt spacing? I saw a 2.25 bore but was right side only. Circle track stuff.

 

[broncnaz]

This should work. http://www.summitracing.com/parts/edd-270300/overview/

The S10 is the D154 caliper style not the same as larger trucks and cars. Many smaller cars and small trucks use the 154 style. The larger style is know as D52 its mount patterin is about 2in wider.

 

[chuzie]

Thanks for finding that fitting. That will save me some work.

Knowing more about the Chevy brake styles is very helpful.

So the 2.25 caliper I found was an AFCO. It is expensive and they only make it for the right side. Is there a database for me to cross bore size with application so I can find the smaller piston I need in the D154 style caliper?

It seems all the major parts houses have removed the piston bore info from their descriptions.

 

[chuzie]

Stop the presses...

I just found this http://pitstopusa.com/i-17620852-afco-undersized-2-1-4-gm-metric-caliper-lh.html

and this http://pitstopusa.com/i-17620851-afco-undersized-2-1-4-gm-metric-caliper-rh.html

The LH is super cheap at $11.99 and the RH is expensive at $74.99. I'm sure that is due to lack of circle track demand for LH undersized.

Question: When calculating for proportion, should I be using piston diameter (bore) or area? With diameter I get 73/27 and with area I get 53/47. Ugh!!

T-bird:3.09375" or 7.51"sq
GM undersize: 2.25" or 3.97"sq

If I have been calculating incorrectly and need to use area then I would need to look for a 1-21/32" or 2.253"sq caliper which likely doesn't exist.

Now the stock bronco caliper is 2.90625" or 6.63"sq. and if paired with the GM undersized and calculated with area, I get 60/40.

So, is it area or diameter?

 

[Apogee]

You want to compare the ratio of the piston areas as related by the square of the diameters, A = pi*(D/2)^2.

There are numerous calipers with 45mm [1.77"] diameter pistons (A = 2.47 sq in), including the 88-96 C4 Corvette, which is also common with the 1993-1997 LT1 F-body applications, as well as C5 (1997-2004) and C6 (2005-2013) Corvettes. That said, only the C4/LT1 units have integral parking brakes whereas most of the others I can think of will have an internal drum in hat parking brake and be significantly more involved in terms of adapting to an old-style Ford 9" rear end.

Wilwood makes some Dynalite nad Dynapro brake kit options with internal drum-in-hat parking brakes, and though the standard rear caliper piston area is typically 3.00 square inches (4x1.38 pistons), they can substitute ones with 1.98 sq inches (4x1.12" pistons) instead.

Tobin

 

[chuzie]

I plan to use a lever lock instead of a caliper mounted parking brake. Time to do some more browsing. Thanks Tobin.