Brake system help

LX Dave · Mar 29, 2020

Ran into a soft pedal problem with the brakes on my '84. Did a 5 lug conversion while staying with rear drums. (95 mustang spindles with the calipers, etc.. and 10" 94 ranger drums out back) Problem I'm having is when I first completed and bled the brakes, the pedal was rock hard and right at the top, maybe 1/2 inch pedal movement before they started getting hard. Now that the engine is in and running, the pedal goes almost to the floor and there's hardly any brakes. They are grabbing, but not much at all.

Here's a list of the stock parts vs. what I currently have.

Stock '84 parts:
Master cylinder-.827 bore
Front calipers-2.36 bore
Wheel cylinders-.750 bore

Here's what I currently have on the car:
Stock '84 master-.827 bore
95 mustang calipers-2.59 bore
94 ranger wheel cylinders-.813 bore

Brakes were bled before the engine was in (no vacuum) and once again with it running once it was in. If I pump them a couple of times with the engine off, the brakes seem to firm up. When I pump them with the engine running, they never firm up. I also noticed with the engine off, it SEEMS like the pedal sinks very slowly, but not 100% sure on this, it was a long day and I was getting tired of messing with them.

Should I have gone with a master cylinder with a larger bore, like a 85 Lincoln town car master or maybe something else? Could this just be the master bore is now too small?
Any thing else I missed?

Stuck on this and couldn't find the info searching through the brake thread. Nothing I could find was for a disc/drum set-up using 95 spindles.

2000xp8 · Mar 29, 2020

This sounds similar to what used to happen to people when they did the Lincoln caliper swap.
Mike (mustang5L5) will probably have your answer, he has all the MC info rattling around in his head.
I have to believe the MC is undersized and you may need the 94/95 cobra unit.
Personally I don't believe in doing one end at a time.
I think it's easier to do all 4 corners at once.

Mustang5L5 · Mar 29, 2020

Long story short, there is no MC that really works well with rear drums and one of the SN95 disk options. Best you'll get is close.

Two options,

94-95 Cobra MC with appropriate 2-3 port conversion which is a PITA to do on a pre-87 due to SAE vs metric brake fittings

Or change the front brake setup to one that is closer in size to the stock 60mm fox body calipers. The 66mm calipers on the 94-98 GT are huge and require a much bigger MC

The closest you'll get to stock feel would be with a 99-04 Cobra 13" front setup. It would be a slightly firmer than stock pedal. Next closest is the 99-04 GT 10.8" setup. It would be slightly softer.

The 94-98 GT calipers are roughly 20% larger in bore. The 15/16" cobra MC is roughly 25% larger. It would be close, but it's a huge PITA to plumb in.

If you are considering rear disk, it would make things easier

LX Dave · Mar 29, 2020

Been checking into converting the rear to disc as this makes the most sense. There's so much info out there and so many different ways to do it, I''m trying to get things straight.

My car currently has a 8.8 rear in it with 5 lug Ranger axles.
I would also, if possible, like to keep the current front brakes. Everything on this car is new.

Would this list be what I need?
94-98 V-6 calipers and brackets
93 Cobra master cylinder
94-95 V-6 brake booster
87-up E-brake handle with weld mod to self adjuster
(2) FMS M-2809-A rear E-brake cables
(1) FMS M-2810-A front E-brake cable
Proportioning valve for rear line
Soft lines from axle to caliper

There's a few 94-95 cars in the yard i go to and could at least get brackets and cores, maybe even a good booster.
OR
There's a ton of 99-04 v-6 cars there too. Anything from them work?

If I have to make up adapter lines, that's no problem. Napa here has all the fittings that I would need and I have the Eastwood flaring tool.

Eastwood Professional Brake Line and Tubing Flaring Tool

Create 3 kinds of precision flares, in 5 sizes of tubing

www.eastwood.com

Not sure if this helps or not, this car was a complete restoration and I had to replace all of the brake lines, so if I have to remake or modify a couple lines, no problem. I really appreciate the help on this.

2000xp8 · Mar 29, 2020

I'd stick to north race car brackets in the rear, this way you don't widen the track width.

Mustang5L5 · Mar 29, 2020

Some of those parts are discontinued. I’ll uodate in the Am once I can type on a keyboard

Mustang5L5 · Mar 30, 2020

LX Dave said:
My car currently has a 8.8 rear in it with 5 lug Ranger axles.
I would also, if possible, like to keep the current front brakes. Everything on this car is new.

Would this list be what I need?
94-98 V-6 calipers and brackets
93 Cobra master cylinder
94-95 V-6 brake booster
87-up E-brake handle with weld mod to self adjuster
(2) FMS M-2809-A rear E-brake cables
(1) FMS M-2810-A front E-brake cable
Proportioning valve for rear line
Soft lines from axle to caliper

The car being an 84 makes adapting the lines for the MC and such a little more difficult due to the SAE vs 87+ metric fittings. If you can cut and flare and get the fittings you need, it will be much easier.

ANyway, you need to decide which brake system you are going to copy. SInce you state you are going to use 95 Mustang front brakes, i would copy the 94-98 GT/V6 setup.

So up front the spindles, rotors and calipers and lines. MC and booster should be 94-95 GT/V6 MC and booster.

Out back, if you want to keep the 5-lug ranger axles, you need the North Race car, or LRS offset caliper brackets. That will let you run the 5-lug axles you already have. Then, pick up all the rear disk parts from any 94-04 GT or V6 mustang at the wrecking yard.

No need to weld the parking brake. There is a cheap clip that allows the brake to be adjusted later.

Brakes - Sn95 Parking Brake (no Need To Weld Handle)

The So I just put a 1998 Cobra leather handle in my car simply for the look. Learned a few things about the fox and SN95 handles. First off, there's no difference major differences in the87-93 and 94-98 handles. The 99-04s use a different mounting pattern (so I would recommend not using...

www.stangnet.com

The ford racing parking brake cables are discontinued. The center cable doesn't work with the 79=86 cars. The rear cables are available from LRS.

Mustang Rear Parking Brake Cable for Rear Disc Brakes (79-92)

Finish off your Mustang five lug conversion with these vital e-brake cables for rear disc brakes!

lmr.com

Ont thing that would make it easier is to grab some 99-04 GT/V6 front dual piston calipers from the junkyard. Make sure the pistons are free as they have a tendency to freeze up when the car sits. WIth those calipers, you might be able to get away with just bolting up an 85 town car 1" MC. Plug and play.

I also made a post about my ideal junkyard 5-lug swap

Brakes - The Ultimate 4-lug/5-lug Brake Conversion/upgrade Thread

. If you are buying new, get the 1993 Cobra booster. I heard of people that did and didnt have fitment issues with the '93 cobra booster. I saw that it was about 50/50 in the LMR review section. The people that got it to fit without banging the strut tower said to just take your time and...

www.stangnet.com

2000xp8 · Mar 30, 2020

Thanks for posting the E brake repair part mike.
Goes to show you how long I've been not reading disc brake conversion posts (I felt for a while there was just too many and no different info was changing hands).
Honestly, I never did anything to my handle. Always seemed to work fine, had to pull it a bit further, but nothing notable.
I could have welded it, I just didn't feel the need to remove it and do so.
I ordered that bracket, the price is way up over the original post years ago, about the best I could find it was $24 shipped at tasca, regardless, it's much easier than removing it.

LX Dave · Mar 30, 2020

Very helpful info there. Thanks for that. Thinking since I already have all new front brakes ('95), I'm going to copy the rest of the system from the 94-95 cars.
Maybe I can even find a parking brake handle that has the clip already on it.

One more thing, does anybody have more details on gutting the proportioning valve? Everything I have found is kind of vague on exactly what to do.
And, should I grab that from the '94-95 car too?

2000xp8 · Mar 30, 2020

If the proportioning valve is the same as 86-93, you just have to buy the ford racing plug and take the parts out of the stock one.
Then you need to do a 3 to 2 port conversion.
For the gutting it, it's as simple as removing a big nut, taking the parts out and replacing it with the ford racing nut/plug.

Mustang Brake Proportioning Valve Plug M-2450-A - LMR

Plug your factory proportioning valve with this 5.0 Resto direct fit Mustang Rear Disc Conversion Proportioning Valve Plug!

lmr.com

I could have sworn my was a real ford part, but I guess whatever works.

LX Dave · Mar 30, 2020

As easy as just pulling everything out and putting that plug in? Well, that WAS easy. Thanks for that.

I did find where someone commented by doing that, you loose the shuttle valve and if there's a major leak, there's no safety anymore. Is that really a concern?

Mustang5L5 · Mar 30, 2020

2000xp8 said:
I ordered that bracket, the price is way up over the original post years ago, about the best I could find it was $24 shipped at tasca, regardless, it's much easier than removing it.

Damn. Price really has gone up on that part.

LX Dave said:
I did find where someone commented by doing that, you loose the shuttle valve and if there's a major leak, there's no safety anymore. Is that really a concern?

I've pulled apart a few combo valves and found the shuttle valve to be frozen in place, especially on systems with old dark brake fluid. I wouldn't put much faith in it.

Mustang5L5 · Mar 30, 2020

2000xp8 said:
I could have sworn my was a real ford part, but I guess whatever works.

It used to be. Then they discontinued it and LRS picked up the slack.

Times sure have changed. A lot of our go-to parts are slowly becoming discontinued and obsolete

90sickfox · Mar 30, 2020

You could swap the whole brake system out of a 94 95. You'd have to use a 93 cobra booster...or move a stud and weld your rod onto the 94 95 booster rod.

I used 98 gt front brakes and sn95 rear with v6 98 prop valve and master cylinder. The brakes wouldn't lock up because of the smaller factory booster in my 89. Would be a b**ty clencher any time traffic stopped suddenly.

Shakerhood · Mar 31, 2020

Mustang5L5 said:
It used to be. Then they discontinued it and LRS picked up the slack.

Times sure have changed. A lot of our go-to parts are slowly becoming discontinued and obsolete

Way back when I did my brake conversion I went ahead and bought doubles of several parts assuming they would be harder to find in the future, wish I had picked up many other parts over the years too, a tubular GT40 Intake is one I wish I had.

KRUISR · Apr 4, 2020

I went with a MC and prop valve from a 99-04 NON-ABS car. They have the single brake line to the rear like a fox. This gives 4 wheel discs, factory brake line routing and an MC and prop valve properly sized. I used a 95 booster (because my original one was frozen to the stock MC and I couldn't separate). Some slight firewall mods will be required to install the booster (and I slightly clearanced the strut tower to slide it in).

As far as a e-brake handle, I used one from an '01 and moved the rear floor mount tab forward about 1" (modded bracket shown below). This bolted right in, was the same size handle and solved the tensioner issue. I fabricated the front e-brake cable bracket similar to an 94-04 and used '95 cables.

Everything I put in was used wrecker parts except e-brake cables and any fabbed brackets.

nickyb · Apr 4, 2020

KRUISR said:
I went with a MC and prop valve from a 99-04 NON-ABS car. They have the single brake line to the rear like a fox. This gives 4 wheel discs, factory brake line routing and an MC and prop valve properly sized. I used a 95 booster (because my original one was frozen to the stock MC and I couldn't separate). Some slight firewall mods will be required to install the booster (and I slightly clearanced the strut tower to slide it in).

As far as a e-brake handle, I used one from an '01 and moved the rear floor mount tab forward about 1" (modded bracket shown below). This bolted right in, was the same size handle and solved the tensioner issue. I fabricated the front e-brake cable bracket similar to an 94-04 and used '95 cables.

Everything I put in was used wrecker parts except e-brake cables and any fabbed brackets.

I also used the 95 prop valve,but I just swapped out the guts.the ebrake I used the clip from a 96.

LX Dave · Apr 4, 2020

Well, I was going to update last night, but carried away pulling things apart last night.

Went to the yard yesterday and got some parts.

Calipers, brackets and related off of a 2004. Master, booster, and dust shields off a '95.

Here's where things get a little strange.....

The anti-moan brackets on the left are off of the '95, the rusty ones on the right are off the '04. Hmm, which ones do I need....glad I got both sets.
I wanted to use the cleaner ones, but they wouldn't fit. The upper control arm bracket is in the way of the U-bolt. My luck, I had to use the rusty ones off the '04.
Still had to trim them to fit though.

Had to cut off about 3/4" so they would clear the bracket on the axle. The U-bolt went through the middle of the bracket and clears. (pic taken after blasting and powder-coating)

Here's where I am now

Caliper bracket attached just to get the anti-moan bracket in place.

You can see where the U-bolt goes through and If it wasn't cut, it would hit the lower control arm bracket.

For the main caliper brackets (ones attached to axle tube), I decided to use the switch and flip method. Cut an opening in the bracket to get them on the inside of the mounting flange and switch sides. This way I can retain the stock axles.

Got new calipers, rotors, pads, hoses, master cylinder and a '93 Cobra booster coming. Going to get a master without reservoir so I can use one from an Explorer or Ranger. They are just a rectangle reservoir with no angled top. I pulled one off a '97 Ranger and it fits the '95 Mustang master. Yep, all these are just for cores. There were no good parts there.

So far, this is pretty easy. (Once things got figured out with the help I've gotten). The hard part is going to be the parking brake. I was all set to pull a parking brake handle out of another car when a light came on. On the '84, the adjuster for the cable goes through the tunnel on the right side of the handle. On '87-up, it goes through on the left of the handle. Gonna have to dig into this more before I order cables or anything. Maybe next week I'll just grab a newer handle and see how I can modify it to work. If I used a '87-up handle, it would end up waaaay off center.

Oh, almost forgot, I did at least get the clip for the e-brake handle just in case I need one.

LX Dave · Apr 5, 2020

KRUISR said:
I went with a MC and prop valve from a 99-04 NON-ABS car. They have the single brake line to the rear like a fox. This gives 4 wheel discs, factory brake line routing and an MC and prop valve properly sized.

How's the brake bias between front to rear? I could do this, but it's going to be a tough one getting the flaring tool down there to put on different fittings. Have to loot at that again.

KRUISR · Apr 5, 2020

The bias is basically like a stock 99-04. You need the Non-ABS one because it is the only one that doesn't have individual lines to each wheel. Think about it, you have 94-04 rear brakes and if you have the dual piston 99-04 front calipers, you essentially are 99-04 brakes on a fox.

I pulled the MC and Prop Valve from the same car and kept them connected. I also took the first 4-6" of the brake lines coming out of the prop valve so that I would have the correct fittings. I don't recall the flare required anymore, but basically I moved the stock fox fitting down the brake line enough to cut off the flare (1/4-3/8" of tubing), swap fittings and re-flare for the new prop valve. I did my change over with the engine out so access was not an issue. If you can't get the flare tool down to the lines, you may be able to undo and remove the line from the car and flare off the car, or remake new lines off car and install.

Brake system help

LX Dave

2000xp8

Mustang5L5

That is…until I whipped out my Bissell

LX Dave

Eastwood Professional Brake Line and Tubing Flaring Tool

2000xp8

Mustang5L5

That is…until I whipped out my Bissell

Mustang5L5

That is…until I whipped out my Bissell

Brakes - Sn95 Parking Brake (no Need To Weld Handle)

Mustang Rear Parking Brake Cable for Rear Disc Brakes (79-92)

Brakes - The Ultimate 4-lug/5-lug Brake Conversion/upgrade Thread

2000xp8

LX Dave

2000xp8

Mustang Brake Proportioning Valve Plug M-2450-A - LMR

LX Dave

Mustang5L5

That is…until I whipped out my Bissell

Mustang5L5

That is…until I whipped out my Bissell

90sickfox

Wasn't a pretty sight...and I've got big hands

Shakerhood

KRUISR

nickyb

I gotta say i never painted my nuts, Never Ever

LX Dave

LX Dave

KRUISR

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