Davidmij - Disc Brake Conversion & Rim Problems

[simplyconnected]

David, I don't want to see you lose any money, and God knows, ABS is VERY expensive (as I have said all along).

Old Irish Dave does NOT sell ABS products. They are competitors. Also, OID sells brake components that carry a lifetime warranty made by MBM.

eBay rules are that the buyer always pays shipping. To make sales more attractive, a seller may put a clause in the listing which says he will pay for shipping IF his products are Dead On Arrival (which yours were, apparently). Did the listing say that?

I hope the owner lives up to his company's reputation and reimburses your shipping costs. I'm dumbfounded that ANY company would send out bad brake components. Terrible.

Based on this experience, I wouldn't suggest anyone buy from ABS. - Dave

[davidmij]

Well shoot, I wish I would have gone with my NM comrade Mr OID then. OID didn't have the parts at the time so he recommended I check ABS if I didn't want to wait. I like OID, he's very helpful and runs a good business.
ABS co-owner Lucio Gomez replied to my e-mail right away and said he would pay for the return shipping. He stated that it was indeed their fault and he wanted to make sure I was happy with their product - so kudos to him. (still not impressed with his manager who refused to pay) Can't wait to get it so I can re-install and go for a cruise. I next need to search the archives for some info on gauges - my temp doesn't work.

[YellowRose]

Davidmij - Disc Brake Conversion & Rim Problems

I am glad to hear that ABS is going to step up and cover the shipping costs. After all, they shipped you a defective product, as they found out when they got it back.

I want to address something since the subject of ABS, MBM and Old Irish Dave (OID) came up. As simplyconnected said, OID sells very good MBM equipment. If I remember correctly, MBM components are built in THIS country and NOT in some other country. He does not sell a lot of dual MC/dual Power Booster equipment that can be used on our Squarebirds, but he has them! His main business involves other makes and years of cars. But he certainly has what we need. Except for one thing! That firewall mounting bracket for A/C equipped Squarebirds. He does not have one that will clear that A/C plenum.

However, if you have a Squarebird and you want to go the MBM route with your new dual MC/dual Power Booster, give him a call or email him. All you have to tell him is that you have a '58-'60 Squarebird and you want to buy the 8" dual Power Booster and the dual MC that goes with it, to put on your Squarebird. He can sell you everything you need for that part of the conversion, except for the mounting bracket to the firewall. He can also sell you those units chromed for about $20 more. Both Howard and I have the chromed version and they look really cool in Howards engine bay, with his engine chrome kit too. OID also has the non-chromed and chromed proportional valve that you will need if you are also doing the front disc brake conversion. Here is the contact information for OID. If you have told him you are doing a '58-60 Squarebird conversion, he will know which proportional valve to sell you.

Old Irish Dave's eBay E-Store - http://stores.ebay.com/The-Oldirishmans-autoparts It has two dual 8" MC/Power Booster systems that will work on our Squarebirds (Not shown on his webpage, but he has them!) $175 plus shipping and chromed - $210 plus shipping. Check the pricing with him as it might have changed. He can be contacted 9:00-5:00... MOUNTAIN TIME...at 575-544-4729.

We still have the problem of finding a working firewall mounting bracket with hockey stick for Squarebirds with A/C. The other vendors will not sell you the mounting bracket that will work unless you buy the whole kit from them. You can save a ton of money by going the MBM route and finding someone to make the firewall mounting bracket, hockey stick, firewall mounting plate, and rubber seal that goes behind it. I am told that http://www.ndgearheadscruiserproducts.com/id23.htm supposedly has a mounting bracket for sale for $75 that will work on our A/C equipped Squarebirds. What we don't know is if this mounting bracket will clear the Squarebird A/C plenum box. That needs to be checked out.

Howard and I got our disc brake caliper mounting brackets from Scarbird. http://www.scarebird.com/ 1957-68 Galaxy, full size '59 Galaxy disk brake caliper mounting brackets cover the '58-'60 Thunderbirds as well, and he has them for sale. Dave, Howard and I believe that other caliper mounting brackets are inferior to his. Tell him you need them for your '58-'60 Squarebird.

As for rims, your OEM 14" rims will not work with this conversion. They are not disc brake ready rims. You will need to find other 14" rims that will work or 15" disc brake ready rims. 14" rims that are known to work on our Squarebirds are:

Disc brake ready rims 14"x6" and maybe 14"x7" rims with a bolt pattern of 5x4.5 and lug nuts 1/2-20 vented rims, are what you are looking for. I am told that offset backspacing and rear spacing are not a factor if you find the following rims. 70's LTD II. 14" Ford wheels with the numbers 43M below the Ford script, a 22 on another lobe of the center and a 3 next to the valve stem. Make sure they are vented rims. They have to be rims made for a front disk brake/rear drums car. Any 1977-1979 Lincoln, Versailles, Granada, LTD II, Torino, Ranchero should work. A 1998 Ford Ranger, 1975 and up Granada, 1974 Maverick, earlier 70's Torino or Ranchero with 14" rims & front disk brakes might work also. Most of these are 6 inches in width. 1995 Ranger wheels go right on and they’re 14”s and our hubcaps fit right on.

Finally, there is one more car to consider. The Lincoln Versailles, a more expensive version of the Granada. The 1977-1979 Lincoln Versailles rims and spindles ARE EXACTLY what you want for a T-bird conversion. All the holes are correct. If you got a hold of a Lincoln spindle, you wouldn't need ANY machining on the lower ball joint hole. It comes exactly how we want it. Problem is, finding an old Versailles! Mustang and Granada spindles are much more available (and we open the taper).

SPINDLES

There has been a lot written about spindles. In some installations the original spindles on our Squarebirds can be used. The Thunderbird Ranch kit of John Draxel comes to mind. For those of us with 14" rims this is important to us. Others prefer to replace those spindles with other models. Granada spindles seem to be the choice of many because they are said to be designed for a heavier car and are sturdier. It has been reported that early vintage spindles have had failure problems, so that is something to consider. If you want to use Granada spindles and don't want to buy them new, what Ford cars can you find them besides a Granada?

Consider the Comet, Cougar, Maverick, Monarch, Mustang, and Versailles. The very best donor cars are the Granada’s and Mercury Monarchs from 1975-1980. 1981-1982 Granada spindles will not work because they are a different style. The Granada was built off the 4-door Maverick car. The Comet was built off the Maverick. Search for Maverick/Comet parts off of 1974-1977 cars. Don't use 1973 parts because that year they used 10" rotors. Consider the 1968-1973 Mustang and Mercury Cougar which have similar spindles to the Granada. However, keep in mind that finding parts for these can be difficult and more expensive. It has been said that you can spend almost three times as much for rotors/calipers. So you might want to stay away from 1968-1973 Mustangs and Mercury Cougars.

If you get a Mustang spindle, the bottom ball joint hole needs to be opened to accept the T-bird ball joint.

[simplyconnected]

Wow, you guys are way too technical for me...

Anyone converting to Power Disk Brakes MUST KNOW, and be personally responsible for their newly fabricated system. All these companies only sell parts and they take ZERO responsibility for your safety, your skills, or your actions. You need to have your head screwed on very straight.

Well shoot, I wish I would have gone with my NM comrade Mr OID then. OID didn't have the parts at the time so he recommended I check ABS if I didn't want to wait...

From Ray's post, you can see we have done our homework. I took on this challenge two years ago when I heard that a Power Disk Brake Setup was not available at a reasonable price for Squarebirds.

First, I retrofit my '59 Galaxie with great success. Then, I got all my Squarebird-ducks in a row with the help of Ray Clark and Howard Prout. I had no problem finding a firewall bracket for the Galaxie.

Howard brought to my attention that the Squarebird M/C uses a different bolt pattern AND the booster must be raised much higher to clear the A/C plenum and his 430 valve covers. THAT threw a monkey wrench in my plans.

We searched everywhere for a decent bracket under $125, and struck out. Finally, Howard designed and fabricated one that works beautifully. Dimensional changes took quite a few tries before he got it right.

...The booster, bracket, and M/C can be purchased on eBay as a kit for $275+. CLICK HERE There are other kits available at better prices, but this is an easy one...

I am NOT pushing this product, but it is on the market with correct parts. I think it is overpriced for a zinc plated system. Remember, OID sells a CHROME booster/master and bracket for about fifty bucks less (but he doesn't have the correct Squarebird firewall bracket). So I reported, ABS does have a system on eBay. I have NO love for ABS and have never bought from them. I'm not impressed with their bracket if it must be shimmed sideways to clear the A/C plenum, but some of our members are successfully using just that.

Finally, I am a restorer. You all know that many classic car parts are made from 'un-obtainium' which forces restorers to either forget it and do without OR make your own. I don't mind fabricating an alternator bracket for my Y-Block, or a firewall bracket for a booster, but I can't make consistant custom parts on a production basis.

Another problem is low 'demand'. About five Squarebird.org members per year upgrade to power disk brakes; hardly enough to merit making dies for our firewall brackets. - Dave Dare

[YellowRose]

Davidmij - Disc Brake Conversion & Rim Problems

Thanks for the additional comments, Dave. One thing that any of you must do if you are considering converting to a dual MC/dual power booster system AND you have a Squarebird with factory A/C, is to ask the company you thinking of buying from if they provide the firewall mounting bracket. If they do, tell them you have A/C on your Squarebird and ask them if that bracket will extend the combination dual power booster and dual MC past the A/C plenum.... It is my understanding that sure, they may have a firewall mounting bracket that will work, IF you do not have A/C on your Squarebird. So, before you commit to anything ask and get a clear answer, if that bracket is deep enough for the dual power booster to clear the right side of the A/C plenum box. If not, you might want to think twice about buying that set up because you are going to have to find a company that DOES have a bracket that will allow the booster to clear that A/C plenum box.

As Dave said, Howard built his firewall mounting bracket, the adjustable hockey stick, the firewall mounting plate and rubber seal that goes behind it. He built one for himself and one for me. After re-engineering it a number of times (he is a terrific designer and engineer in my book) to the point that he was happy with it and it works operationally correct on his Squarebird, he made a set for me. I am about to go through the conversion process shortly. I do not know if he wants to get into the manufacturing business on making these parts for Squarebird owners with A/C in the cars. He will have to comment on that.

[Astrowing]

As Dave said, the firewall brackets are a structural safety item and are to be taken seriously. It has to work. If it were to fracture or come loose from the firewall, you'd lose braking capability and that dual reservoir master cylinder won't do you any good. Same comment applies to the pushrod. Has to work.

[davidmij]

Well I got my MC back from ABS and installed it today. I also replace the brake pedal assembly with a brake and clutch assembly that I got from Greg. It was a bit of work but I got it all back together and everything works. The clutch pedal will be used some day down the road when I install a 4 on the floor.
Anyway, as soon as I fired it up I could feel the brake pedal drop so I knew the power booster was now working. It's very drivable but I still can't get it to skid the tires on a stop. It also pulls slightly to the left. It's was a long day so I decided to wait until tomorrow to see what else I can do to make it brake better. Just to reiterate - the front reservoir nearest the radiator is the little one - I should have that one feeding my rear drum brakes? And the larger reservoir nearest the firewall should feed the front disc brakes? I plumber the proportioning valve the same way as the picture that was posted here. The pedal is good and firm, no air in the lines. All my linkage etc is smooth and accurate - came out really well. I'll look at the manual to get ideas on adjusting the rear drums. Does it take much to change them out to self adjusting?
thx, Dave J

[Dakota Boy]

larger reservoir is for the front discs

[davidmij]

Thx Greg - that's what I thought but somewhere I had gotten it in my head that it was the other way around. Can anyone tell me why it's larger when there is less fluid required to fill the front lines? Is there a difference in the capacity of fluid that each half has in the piston cylinder?
- Dave J

[davidmij]

Just found this while googling, "I've seen many disk/drum where the bore is identical. They have a bigger resevour for the fronts because the calipers hold more fluid as the pads wear down and the pistons extend and stay that way. Different bores would create different pressures front to back and the average failure switch would trip immediately."

[JohnG]

It's not the bore of the MC all by itself that matters but the ratio of that bore (or really it's cross sectional area) to the total area of the two pistons in the front calipers, additionally that ratio as compared to the ratio of the area of the MC piston for the rear as compared to the area of the rear (drum) pistons.

A ball park estimate is that the ratio of front to rear pressure results in 70% to 30% as much more of your stopping is done by your front brakes than your rear.

To further elaborate, if your front MC piston is relatively large compared to the total area of the two pistons in the caliper then you more easily move more fluid and get a "harder" brake. Reduce the area of the MC piston and you get a bit more pedal travel and a more "linear' feel to the brake. Different people have different opinions on a most desireable set up.

At the heart of it, you press the brake pedal, move a shaft which pushes on either 1 or 2 MC pistons. For a given movement of pedal you get a given travel of an MC piston. Multiply that travel by the cross sectional area of the MC piston and you get the volume of fluid moved.

At the other end, at the brake, the same volume of fluid moves since brake fluid is almost perfectly incompressible. How far the brake caliper piston moves is then determined by it's own cross sectional area since the same volume equals the cross sectional area multiplied by the travel of the caliper piston. Divide by 2 for two calipers.

So all other things equal, a larger MC piston moves more fluid and thus results in more movement at the caliper end.

Probably more info than anyone wanted but the bottom line is that the behavior of these systems is pretty simple and results from simple ratios and geometry.

[davidmij]

Thx John.
Actually that's not too much info, that was right on target. I believe I understand now why the larger (longer?) half pushes more fluid, and that it needs to because the front calipers are larger and require more fluid for stopping power.
One more dumb question though - is it better to bleed the brakes with the engine running (vacuum assisted) or does it really not matter?

- Dave

[jopizz]

It doesn't matter but for safety sake it's better not to have the motor running. Plus it's just a waste of gas.

[simplyconnected]

...I still can't get it to skid the tires on a stop. It also pulls slightly to the left...

Every time you let off the brake, your M/C opens the reservoir to the line (front and rear, independently). Disk and drum systems work differently.

Caliper pistons never really retract, but rear shoes push their pistons back, returning much more brake fluid to the M/C. Next cycle, same thing... Calipers use little fluid to squeeze the rotor while rear pistons use a lot of fluid to push shoes that are rarely adjusted close to the drum.

What happens to the combination proportioning valve? The internal spool starts travelling towards the system that uses the most fluid (as it should).

So, the larger reservoir is used on the largest wheel cylinder pistons, which is the front calipers.

If your system feels mushy, won't lock the wheels, or pulls, you have air in the wheel that feels mushy. Because brake fluid returns to the reservoir, SOMETIMES the air will burp itself out. Normally, air gets trapped in the wheel cylinders.

If you never 'bench bled' your M/C, there may be loads of air in it.

[davidmij]

Hey Dave, thx for the info. I'm not sure why, but I didn't get a notice that you had sent this.
I've been busy watching our mountains burn here in Los Alamos this week - very sad. Luckily it hasn't come down to White Rock where I live (yet).
So how important is it to bench bleed the MC? I did that once before many years ago, but it seems to me that the regular bleeding with a hose and a can would be good? My pedal is firm and has a short travel range. Seems just right except that it just doesn't stop the car as well as I thought it would. Should I pull the MC and bench bleed it?
thx, Dave J