Disc Brake Conversion
Haven't been on the forum for a while now. I am re-locating from Western Australia to Tasmania in the next few months so have been commuting for the past six months or so & have bought a house in Devonport.
A lot cooler climate there so will be great cruising country. Can't wait!!
Before I send my 59 TBird over, I am looking at converting to front disc brakes.
I know there are a lot of threads already on the forums but the more I read, it all becomes a little confusing.
What I have decided to do is go down the path of using 1968 Mustang 11" rotors (so I can still use the Squarebird bearings.)
GM S-10 calipers & a two stage 8" booster & dual reservoir master cylinder.
The calipers, rotors, booster & master cylinder are readily available in Perth through the Mustang club that I am a member of.
I have sourced the caliper brackets from Scarebird.
Before I go ahead & purchase these items, I need to clarify a couple of issues.
My Tbird is 352 engine & has factory air con. & under dash booster.
My questions are:
1. Except for new brake hoses, bolts etc. do I have all the major parts I would need for this conversion??
2. I have read on previous forums that because of air cond, space for the booster is critical & I would require, I think, a special "banjo" shaped arm for the master cylinder.
I can't find the thread where I read about this so am going by memory at the moment.
Will I require a "banjo" shaped arm & where can I get one please??
Hope all this makes sense as I am NOT a mechanic but need to have all the necessary parts to give to the "real" mechanic.
The critical area as you mentioned is the space between the booster and A/C plenum on the firewall. I had and used the original under the hood booster so needed a bracket to extend the original pedal assembly and booster out 3/4 inches to clear that plenum. Because I moved the pedal assembly out 3/4 inches I also needed a longer pedal rod. I just extended a stock one. There are aftermarket adjustable rods as a replacement. You may need a new brake pedal rod between the original booster and the new bracket that will be mounted on the firewall (if you plan on leaving the old one in place) or a new rod between the old pedal and new pedal bracket that will be mounted on the firewall. Hopefully someone here has used the new style booster and bracket on an A/C car and can tell you if and how it works.
Don't know on the bearings - unfortunately I went with the Granada setup.
You will need a combination valve. I used this one but I think the disc/drum valves are all about the same. Most likely can be sourced from your Mustang supplier.
The "banjo" fitting usually refers to the bolt used to mount the flexible brake lines to the front calipers. A banjo fitting allows the line to be installed at a 90 deg angle from the caliper giving better clearance. I posted a pic of my Granada calipers with the installed banjo fitting. There is a banjo fitting on the original master cyl but it won't be used. The new master cyl should have new solid lines to the combination valve and from there on to the calipers and rear cyls.
The brake light switch is currently on the end of your master cyl. That switch will either need to be moved to the rear brake line or replaced with an electrical type. Might be a challenge to replace the switch with the electrical type on an A/C car with the booster still in place - I didn't go that route. Posted a pic of where I installed mine. It is the original fluid type switch in the splitter for the rear brake system at the old master cyl input. Either way I would expect a little extra wiring will be needed.
You might also consider a firewall boot plate kit again from the Mustang supplier or from Master Power Brakes.
Some good info so you will know what's involved.
Good luck on it,
My booster and A/C plenum clearance
"Extended" brake pedal rod and bracket I had fabricated and added between the firewall and pedal bracket to move my booster out enough to clear the A/C plenum (may not be needed with the newer brackets).
Banjo bolt mounting the front flex line to the caliper.
New position of brake light switch
Eric offers sound advice, and I agree with it.
Let me add my two cents since I have done this conversion as well on our Galaxie. There is a company that sells the booster/master combination with the firewall bracket. I have no love for them because I think their prices are high BUT, I'm not down under and I have plenty of resources readily available here in Detroit.
ABS Power Brake offers this setup on eBay: CLICK HERE
It includes the necessary two-stage 8" booster for front disk brakes. Eric's booster is a single stage (from the day) and it was designed for drum brakes. The ABS booster combo may be available in chrome if you call the company.
ABS is the ONLY company I know who sells a proper firewall bracket. Some of our members have made their own. The deal is, you need to raise your booster up five inches and out another five inches. This clears the shift levers on your steering column, your A/C plenum and your valve covers.
Most recently, Marcelo converted his Squarebird using a stock 1960 PB firewall bracket, and adding his own spacer to it. His setup ended up nearly identical to the ABS system. Here is his setup: CLICK HERE.
Since then, he mounted his combination proportioning valve on the fender apron for more spark plug removal clearance.
Some have left their hyrdovac booster in place. Others have pulled it out. Your choice because you don't need it. Some have left the vacuum can to help their stock vacuum wipers. Others have abandoned it because they went to electric wipers. The ABS booster comes with plenty of capacity and it has its own check valve.
Buy a good pair of 3/16" brake line bending pliers and an inverted flaring tool. Several companies make them. They make this job much easier because I guarantee after plumbing your car, you will be good at it. - Dave
Does the booster (if original) deliver enough line pressure to ensure safe stops?
Yes - that is a rebuilt firewall mounted stock booster and unmodified stock pedal assembly (drum) however it has had the face of the booster changed to a Lincoln ('61-63 I believe) to accept the 2 bolt style disc/drum master cyl. The Lincoln booster of that year is the same except for the face or part where the master cyl mounts. I had Booster Dewy (Power Brake Booster Exchange) rebuild and modify mine 10 years ago - still going strong and working perfectly.
It feels and stops like a modern disc drum system. If you have ever driven a E series Ford van - it feels exactly like that to me. I'm sure the dual action booster would be better but I was aiming for the dealer installed look (and half the parts available now were not out there 10 years ago)
That all worked fine for 9+ years then about a year ago I decided to add factory style A/C with the plenum on the firewall. The original firewall mounted booster hits the A/C plenum. That's where the extender bracket comes in. Ford had a kit to move the assembly out but I've only seen 1 in the past 10 years. The dealer kit moved the booster and pedal assembly out from the firewall 3/4 of an inch and up a few inches (not sure how much up). It mounts between the firewall and stock original pedal assembly.
That kit also included an extended pedal rod to compensate for moving the assembly up and out (see pic of factory kit below).
I never was able to find a dealer kit so just made my own which only moved the assembly out not up (it should be moved up a bit but I didn't know any better because I only had pictures of the bracket). I was also only able to find a Lincoln master cyl (which I thought I needed to match the Lincoln booster face) and it's ports are on the wrong side. I think there is a Mustang master cyl that will work with the ports on the fender well side but my system works so nicely I haven't pursued that info.
Dave makes some great points - I appreciate him adding his expertise.
I REALLY like the way Marcelo did his booster conversion - wish I had thought of it.
Hope you don't mind me posting this info in your thread Lex...good luck in your re-location.
I'M sorry... I didn't realize I was stepping on another's thread.
Thank you for clarifying your upgrade...;)
Now was Marcello's conversion done with a JEEP mounting bracket?
I'm trying to understand why FORD used an internal and external booster and which went with the factory outside AC plenum.
I would also like to know if anyone has done a front disc conversion with the internal booster and how it performed.
No, no, nooooo... Marcelo used his original 1960 OEM firewall bracket, but cut the rivets and booster off.
He left the bracket on the firewall as it was originally. The brake pedal rod was already connected as a pure stock setup. He left that as is. So, everything from the firewall bracket to the brake pedal are (unaltered) stock.
Marcelo took a (2"x5"-long) square tube and slit it down the sides (as they say at Ford, 'half in two'), leaving one leg slightly longer than the other. Then he bolted it to the original firewall bracket on one side, and his new two-stage booster on the other side.
Look at the picture. It shows his fabrication against the booster:
The end result is: ~5" up and ~5" out.
Marcelo had the Jeep bracket but favored using an old trailer hitch tube. He tried a few different mods as he went, but he ended up using a (Corvette-type) 1"-bore M/C with a two-stage 8" booster. He also mounted his comb. prop. valve to the fender apron, and plumbed to it. I guess it was a more secure setup for the brake switch that was hanging out.
This setup will clear an original A/C plenum. - Dave
Lex, I got the ABS unit from ebay. Think it cost me around $400 at my door. Its a good unit. The only thing I can see at this point is it flexs a bit from the firewall. Im going to make a bracket to hold the prop valve and brace the booster aswell. For rotors, I got 71 Galaxie spindles, rotors and calipters. The spindles bolted on giving instant disc brake setup. Got em for $100. No stuffin around. Good luck with it. Stu
Disc Brake Conversion
Thank you guys for all the replies & advice.
With all this info I'm sure there won't be too many dramas.
I only have one question (at the moment) that I'm not sure about.
Regarding the ABS booster & MC offered on Ebay, the description on Ebay says disc/disc.
Is it O.K. to use this unit if I am fitting front disc brakes only or should I be looking for a disc/drum unit??
Thanks again guys.
You fellas are awesome!!!
There is much discussion regarding this retrofit. For decades, we have enjoyed the superior braking power of disk brakes on hundreds of different models of modern cars. Naturally, we want the same for our classic car. The problem is, none of these systems were designed for a Squarebird, much less by Ford. Disk brakes were not offered in any Ford car back then.
Each of us who retrofits our brake systems needs to do extensive homework before inviting our families to climb aboard for a cruise. Learn the difference between a combination proportioning valve, a residual valve and a flow control valve. (It seems lots of folks interchange these parts but they are operate very differently.) Learn what makes a master cylinder suitable for disk/disk or disk/drum, and how to 'bench bleed' a M/C. Learn booster pressures required for wheel piston sizes. Each component needs careful scrutiny for compatibility and suitability, then rigorous testing must be performed. Make sure your emergency brake works well before cracking any brake lines.
Just because the brakes 'work', doesn't mean they are safe. I see this a lot in the Electrical trade. Even if you studied brake systems, hire an expert to thoroughly test your system. If there is any problem, you want him to find it, early-on.
None of the component manufacturers take responsibility other than replacing their factory defective parts. And notice, no company offers a complete system specifically designed for a Squarebird. Finally, who knows the mechanic's assembly ability or aptitude unless he is certified to work on brake systems? A simple mistake like allowing the firewall bolts to work loose will turn a seemingly good brake job into a useless brake pedal.
I have done a few of these retrofits and I can say that it requires patience and skill. Every part must be good and on-hand before the job starts. Several of our members have also retrofit their Squarebirds successfully. I have yet to see two systems that are identical. So, one member may suggest one part he used, and another may suggest another from a different system. Again, do your homework. Everyone here wants to see your successful brake job and we are eager to help. Ultimately though, it's your car and your responsibility. Good luck. - Dave
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