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Any recs on brakes?

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Littlebeefy

Any recs on brakes?

Hi guys,

I'm not loving my brakes. I'm going to make some calculated changes and I'd love some advice. Here's what I've got now: I've got a set of T-bird calipers up front and stock drums (and stock cylinders) in the back. I have a hydroboost and a Wilwood tandem MC with a Wilwood prop valve.

Currently the brakes feel weak. Also the pedal feels mushy and not a lot of grabbing power until closer to the bottom. We have bled the hell out of the system; there is no air in it. I added the hydroboost thinking it would help but it only makes it feel "mushier".

First off, I know I want to switch out my rears for some discs. I know most of the benefit of the brakes is going to come from the front, but I need the upgrade back there for towing. Plus the stock parking brake needs to be upgraded. I'm not considering the El Dorado brakes because I've heard about how difficult they can be to align properly. My buddy, who knows all things, said that the Ford Explorer discs with an integrated parking brake drum is the way to go. Moser sells a kit for the 9" that seems to be a pretty complete setup. They also sell a Wilwood package for the rear that is a 4 pot caliper with a 12.9" disc and 50% more pad surface than the Explorers. Anybody have any experience with either of these packages?

Also, what about the MC? It's a 1 1/8. Is my bore too big? Is it too small? Do I need to switch out the rears and then assess the MC? I have the MC from the F450 that I took the hydroboost out of, and I think that's a 1 5/16 bore. I also have a 1 1/4 bore from Duff that I tried before I went hydroboost but didn't love.

LittleBeefy aka Chad

“Dot Doitall”: 1984 Bronco XLT
460 (C8VE), Edelbrock Pro-Flo 4, ZF5, NP205, D44HP solid axle, 4.56
urban assault vehicle

"Bebe": 2022 Bronco Badlands 2dr
2.7l, Sasquatch, Iconic Silver, Black Marine-grade interior, hard-top

"Celeste": 1979 Porsche 928
4.5l K-jet, 5-sp, S4/GTS brakes, LSD, Pasha interior

85lebaront2

Re: Any recs on brakes?

Administrator

Interesting issues. I have only had two vehicles with Hydroboost, both GMs with the 5.7L Diesel and their brakes were the typical GM, lock if you look at them on wet pavement.

I did a rear disc conversion on my best friend's 1995 F360 crew cab DRW pickup, his is a Powerstroke and uses a vacuum pump to operate a conventional booster and he was complaining of poor stopping power. One night we had been working at my old house getting it ready to sell and in the interest of expediency I told him just drive Darth. First corner he almost put both of us through the windshield.

The disc conversion was by a company called EGR brakes and is essentially GM stuff. It took me a bit to get it right, I have a lengthy document I put together with pictures showing the issues. His ultimate cause was a bad vacuum pump.

If I were to do a rear disc conversion, I would prefer a drum type parking brake for two reasons (a) one less potential leak point where the parking brake actuator goes through the caliper and (b) the drum style parking brake can be used even if the caliper is broken. My 1986 Chrysler LeBaron has this style rear disc brakes.

Before I went any further, I would look at the stock caliper, master cylinder and rear wheel cylinder sizes. FWIW, the larger the master cylinder, the greater the force required, smaller takes less force, but will have more travel.

Bill AKA "LOBO" Profile

"Getting old is inevitable, growing up is optional" Darth Vader 1986 F350 460 converted to MAF/SEFI, E4OD 12X3 1/2 rear brakes, traction loc 3:55 gear, 160 amp 3G alternator Wife's 2011 Flex Limited Daily Driver 2009 Flex Limited with factory tow package Project car 1986 Chrysler LeBaron convertible 2.2L Turbo II, modified A413

Gary Lewis

Re: Any recs on brakes?

Administrator

In reply to this post by Littlebeefy

I don't have any experience with which to answer your question. But I do have hydroboost on Big Blue, and there's nothing mushy in any possible way with it. If you press on the pedal you'd better want to slow down NOW.

I'm using the F450 master that came with the hydroboost unit and kept the rear wheel cylinders stock. But in front I'm running the '95 F350 calipers that came with the D60.

Anyway, all I'm saying is that my hydroboost system works very well. It may not be perfectly balanced, but I've not had any problems with it in any situation.

Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

Bronco Carl

Re: Any recs on brakes?

In reply to this post by Littlebeefy

I used MK five (1977 or 1978) Lincoln rear disc on a 9 inch rear in my 94 F150. Worked great! I used the same rotors as the fronts, they may have to be surfaced to reduce the thickness. And different wheel studs to locate the rotors to the axle. You also get a heavy cast iron rear bearing retainer which is the caliper mounting bracket from the Lincoln. These calipers use a ramp-ball type park brake using the rear pads for the park brake. Do not use any GM rear calipers, ever, total junk.
I had excellent brake balance using the drum brake master Cylinder, booster, and proportioning valve. I checked the master Cylinder rear output port for a check valve and there was none making it acceptable for rear disc use.

81 Coachman F-250 Motorhome, 85 F-250 460/4 speed, 77 Bronco

Ford F834

Re: Any recs on brakes?

Administrator

In reply to this post by Littlebeefy

I have installed a F450 Superduty hydroboost system (booster + large bore MC) on my F150. The result was very aggressive braking with almost no pedal travel. My stopping ability is definitely traction-limited.

I have considered rear disc brakes on my F350 mostly because drum systems are tedious to service. But since you mentioned towing, keep in mind that rear disc conversions often trade better performance for less friction area. It is pointless to try to compare a hypothetical system to the stock one, not knowing the pad material, heat transfer rate of the rotor, etc., but my experience towing our 28’ Streamline camper with the hydroboost F150 was that traction limited became heat fade limited quite quickly. I would be in no hurry to trade friction surface area for more aggressive performance (which the hydroboost already seems to provide in excess). My Ford 9” has the 11” drum option. I’m sure there are rear discs that outperform the drums on a 9”, even regarding brake fade, but it won’t come from a low end kit, I don’t think. After experiencing how bad rear drum brakes weren’t on the F150 I have pretty much lost any interest in discs for my F350.

Don’t know if this helps at all, just relating my experience with one solution to crumby brakes. My system needed completely gone through regardless… and I chose to replace with F450 booster and MC.

SHORT BED 4-DOOR DIESEL: 1986 F350 4x4 under construction-- 7.3 IDIT ZF5+GVOD

STRAIGHT SIX 4X4: 1981 F150 2wd to 4x4-- 300 I6 close ratio diesel T19, hydroboost brakes, Saginaw steering

BIG F: 1995 F-Superduty under construction— converting to 6.9L IDI diesel ZF5+DNE2

Bronco Carl

Re: Any recs on brakes?

In reply to this post by Littlebeefy

The rear disc's on my 2000 F350 Super Duty are not as capable as the 12 1/8 x 3 1/2 brakes I had on a 1987 E350 class C motor home. Any drum brake truck with with a heavy load on it at all times such as service bodies loaded with tools and parts or slide in campers would benefit with the use of larger diameter wheel cylinders.

81 Coachman F-250 Motorhome, 85 F-250 460/4 speed, 77 Bronco

Pete Whitstone

Re: Any recs on brakes?

In reply to this post by Gary Lewis

I have to say, I feel exactly the same as Littlebeefy about my brakes. The brakes in my 2006 F150 are a different world, compared to my 81.

I too have bled the system multiple times and I'm about positive there is no air in there. I've changed just about every part of the system, including the MC (yes I properly bench bled it before install).

New calipers, new braided SS brake lines, new pads... but zero change to how the system feels. How it feels is, typical 80's overboosted, mushy, insulate you from the driving, no pedal feel brakes. They do work if you really lay into them. I'm not sure I could actually lock my front wheels, though. I realize that "impending lockup" is the state you want them in for maximum braking, and they can get there.

Maybe I've driven post-y2k trucks for so long that I forgot what they felt like in the 80's. I'd sure like to drive someone else's truck to evaluate both my brakes and my steering (which seems somewhat wayward with everything replaced except the steering gear box, which was adjusted by my mechanic).

I'd love for my brakes to have the more-instant, commanding feel that my 2006 truck has. When you talk about F450 MC's and hydroboost systems, what year parts are being used? What are the details of the conversion, anything to know besides having to run lines from the PS pump?

81 F150 Flareside, Edelbrock Pro Flow4 FI, hydraulic roller 351W, E4OD, 4x4, BW1356
92 F150 RCLB 351W E40D BW1356 mostly stock

Gary Lewis

Re: Any recs on brakes?

Administrator

There is nothing mushy about Big Blue's brakes. You touch the pedal the wheels will slow. You hit the pedal hard the wheels will stop. And it is easy to modulate between the two.

The F450 that Jim parted out was a '95, and that's where the hydroboost unit, master cylinder, and the Saginaw pump came from. But you don't need to change pumps as you can easily use the original C-II pump. You'll have to reroute the output from the pump to the hydroboost unit and from there to both the power steering box as well as the return. But that's not hard to do.

And speaking of the power steering box, they are not supposed to be adjusted. They are set at the factory and if they wear you can adjust it and you'll find you can take the wear and the "feel" out or you can put the wear and the feel back in. They go hand in hand.

The issue is that the cast iron of the steering box is used as the front bearing on the steering input shaft. So when it wears you have slop. You can replace the box with a Cardone or some other rebuilt unit but it won't have the front bearing replaced, so you'll have some slop. To my knowledge only Red Head and Bluetop bore out the box and put a real bearing in, and that is what is needed to take out the slop.

Gary, AKA "Gary fellow": Profile

Littlebeefy

Re: Any recs on brakes?

In reply to this post by Pete Whitstone

@Pete - you described my brake feel exactly. I just want a little bit more and I run out of pedal. Also, I had the exact same steering float. That front end is not a great design in my opinion. How old are your coils and shocks? Have you tried a Borgeson steering shaft to eliminate play? Swapping to a solid axle up front has given it a tremendous improvement and I feel much more confident in the steering wheel over all. That's a whole other topic though...

My kit is not original at all. The hydroboost came from either a 97 or a 99 F450 (possibly a 95 haha). It's got the blue canister. Pretty much identical to everyone else's except for the exotic metric thread for the fittings. My pump is a heavy duty Saginaw. After I put the hydroboost in, the pedal felt softer, but no improvement in stopping power. I have 35s so I know I'm asking a lot but it seems like with the t-bird calipers up front I should be able to lock the front up if I lay full on the brakes. I'm using a Wilwood MC (both before and after hydroboost install) so that is suspect in terms of bore size.

I guess I have two separate questions:

1. the pedal feels too soft and "runs out of juice" at the end of travel. Does that mean I should increase the bore size of my MC?

2. What is going to give me better brakes for stopping distance if I'm hauling/towing: 12"+ rear discs or F350 wheel cylinders in my drums?

Bronco Carl

Re: Any recs on brakes?

In reply to this post by Littlebeefy

I was an automotive machinist for 30 years. Back in the 90's I discovered that the Dayton calipers used on the later 80's F250 and F350 would expand a measured .060 in. Causing a mushy pedal feel at times. Usually on the diesels with a vacuum pump that delivered a full 25 in. of vacuum giving the booster more power. We would sell the customer a 1 1/4 Dia. master cylinder from the Super Duty reducing the maximum pressure output. This solves nothing, but gives the customer a better pedal feel.

The original Dayton calipers used in the 70`s did not do this they were much heavier built!

I also resealed a lot of the Bendix hydroboost units, even the ones from GM diesel cars. They are good units and pretty trouble free.

81 Coachman F-250 Motorhome, 85 F-250 460/4 speed, 77 Bronco

Littlebeefy

Re: Any recs on brakes?

Resurrecting this thread.

I had to pull the chunk on my 9 inch so I already have the drums off and could swap out wheel cylinders pretty easily. Should I put in the f350 wheel cylinders? Is my Wilwood 1.125 bore sufficient for the upgrade?

Gary Lewis

Re: Any recs on brakes?

Administrator

Chad - First, thanks again for the Bronco bucket seats. Just got home late last night and will be reporting on them soon. And, btw, I had a sticker for the forum laid out in the truck for you but forgot to give it to you. Will mail it to you soon.

Second, brake mod issues are complicated, which is surely why you've not gotten a response. But let me try to find the spec's involved and let's see if we can find an answer.

The standard brake wheel cylinder for your Bronco was 1" in diameter, and an '84 and later F350 SRW would have a 1" wheel cylinder. However, the MPC seems to say that they are different part numbers, although I can't really confirm that as I can't find the number for the Bronco, but the F350 is E2TZ 2261-B and E2TZ 2262-B.

So, I'd go back with the appropriate cylinder for the Bronco.

Gary, AKA "Gary fellow": Profile

Littlebeefy

Re: Any recs on brakes?

Gary - you are welcome. I'm glad they found a home where they will get another life. Use them in good health.

As for the brakes, I did some research Rock Auto style.

OEM 84 Bronco
MC bore: 1"
Wheel Cylinder bore: .93"

OEM 84 F350 (diesel, non-dually)
MC bore: 1.125"
Wheel Cylinder bore: 1"

Napkin style calculations on W = F x d would indicate that I am still maintaining relative force between MC and slave. Plus, if I am using a Wilwood 1.125 bore, I would think I'm close to stock F350 on the MC (admittedly no idea on stroke).

Anyone see any flaws in my numbers or logic here?

Gary Lewis

Re: Any recs on brakes?

Administrator

Chad - I agree with your calc's, but I'm not sure you have the right data. In fact, I'm not sure what the right data is!

In the screen grab below, which is from a portion of the MPC that is on our page at Documentation/Driveline/Brakes and is for your Bronco, I've highlighted things that confuse me.

But first, a word about nomenclature. When the MPC says "80/" it means from 1980 through the end of the coverage of the catalog, which was 1989. But "84" means for that single year.

In the listing at the top for Cylinder Repair Kit it seems to say that a 15/16" wheel cylinder was used from 1980 through 1989, but in 1984 only there were 1" wheel cylinders used on vehicles built prior to 10/83.

In the listing for the Piston it seems to say that there was a 15/16" piston used from 1980 through 1989, and a 1" piston used from 1984 through 1989.

In the listing for the Shoe & Lining kit it seems to say the 15/16" piston was used for 1980 through 83, and a 1" piston was used for 1984 & 85, but there is no mention of 1986 and later.

So, were I you, I'd measure my wheel cylinders. But my guess is that the 15/16" piston was used from 1980 - 10/83 and the 1" piston used from that point on.

Also, did you use the hydroboost brake pedal in your conversion? It has a different "throw" than the stock pedal.

Gary, AKA "Gary fellow": Profile

Littlebeefy

Re: Any recs on brakes?

In my case I am certain of what wheel cylinder is in there because I put them in myself last year. They are definitely the .93" bore. I may have originally had a 1" in there, but I definitely don't now. But seeing as a 1" bore wheel cylinder was in there at some point with only a 1" bore MC (according to the MPC), I don't think I have any concern about popping in 1" slaves

Luckily because of your forum I knew how important that brake pedal was and I did get it.

Quick lesson to all: I went to the yard to pull the hydroboost and other parts from a single F450. I was about to leave with all of the parts, but I went ahead and measured the rod distance just to double-check. Lo and behold, someone had already swapped the pedal assembly out with a vacuum style and I was about to leave with the wrong one! The moral of the story is, always double-check your measurements and part numbers because parts trucks don't come straight from the factory.

Gary Lewis

Re: Any recs on brakes?

Administrator

Yep, I think you’ll be fine then with the 1” slaves.

And glad you got the right pedal. I suspect that it makes a huge difference in the “feel” of the brakes.

Gary, AKA "Gary fellow": Profile