Brakes bled and pedal goes to the floor but I do stop... sort of.

[chuzie]

Last night Chuck and I did the T-bird front caliper conversion on my '77 in hopes it would improve my ever so crappy braking action.

Calipers for a 78 T-Bird
7/16-24 Banjo bolts from BC broncos
New pads

I removed the old calipers and then removed the outer brake lines. We used the drill press to drill a 7/16 hole in the banjo fittings and then reinstalled the lines to the new calipers, installed the new pads, and bled the system.

Took it for a drive and there is a slight difference but I still can't lock up the front tires. So we can completely eliminate the front end as the culprit in my system. I guess I can change the cylinders in the rear next.


MASTER CYLINDER

'69 El Dorado (4120)
-------
Bore: 1.131 (slightly more than 1-1/8
Stroke: 1.559
Cylinder Depth: 8.015
Piston Diameter: 1.120

CALIPERS
'78 T-Bird

[jdowns67]

Chuzie, I have read the same thing about air getting trapped in the calipers. Wonder if you could try removing the calipers with the lines still attached and bleed with the bleeder valve vertical? Stick something in the calipers between the pads so they don't extend out all the way. I think years ago when I did my F150 disk brake conversion, that's what I did.

JD

[chuzie]

Funny you mention that; it is exactly what I did just to make sure I got all the air out. Actually the first caliper I did that on I forgot to completely tighten the banjo bolt and got fluid everywhere. Thanks for the suggestion though. I am going to look at taking actual pressure readings as well as look into determining if I have a stock brake pedal. Something has gotta give.

[jdowns67]

OK, all this information is probably in there somewhere but... what size tires are you running? if you are running like 37s or something maybe it's as good as it's gonna get with "factory style" calipers and rotors. I only have 33s on mine and I don't think I would be able to lock up the front tires. Does it stop pretty quickly? Think about the fact that when guys do resto rods or brake upgrades on mustangs, camaros, etc... they usually put like Brembo dual or triple piston calipers and gigantic diameter rotors and they aren't running anywhere near the rotating tire and wheel diameter and mass that you probably are. Also, the Bronco weight itself is pretty heavy for normal calipers.

Are you comparing the braking performance of yours to another EB with similar setup?

Also, are you using a MC with a residual check valve for the rear?

Not trying to be funny or disrespectful here..do you have the front/rear plumbed to the correct port on the MC?



JD

[jdowns67]

Found this. pretty good. I like reading this kind of thing as a "refresher".
http://www.autoshop101.com/forms/brake02.pdf

[chuzie]

Running 35s that are worn down to 33. It is a 69 eldorado mc with the residual check since they ran drum in the rear. the lines are plumbed to the correct ports and my weight is typical and performace is compared to other broncos like broncomatt's. i have also had folks drive my rig and comment on the poor braking action.

thanks for the link. i will give it a peek.

[broncomatt]

You know my number dude, give me a call.

[scbronco]

Chuzie, i read something somewhere once that said there was a difference in the hardline diameter and wall thickness for disks versus drums. i dont remember where i read it or what the ditinction was, but it may be something to research.

[chuzie]

I will look into the diameter issue. Thx.

Matt, this is the same issue we have beat to death time and time again. I may give you a buzz this week though, thanks.

[blazinchuck]

lmao...its funny...i have old arse front calipers,new rear calipers, a 3 year old booster/MC and what the heckever brake lines...and all that equals SWEET brakes lol