I metioned in an earlier post that my '81 MCC/Barth came with a bunch of brake parts. I've pulled everything out of the storage bins and gone through it all. It looks like somebody was in the process of upgrading to dual piston brake calipers from a Ford CF6000 (someone had marked the calipers "Ford Cargo 6000", after some internet research I deduced that this must be the CF6000). I am wondering if anyone has heard of this conversion? I am going to dig into mine and see if I can do a mockup on one corner. I'm not sure what rotors would be required. Will update as I make progress. Any information would be appreciated.

I tried the mockup tonight. The only caliper bracket that had been modified was done so incorrectly, so I was unable to mount a caliper and determine the match with stock rotors. I'll try to post some pics later. It is an interesting scenario and looks doable if the caliper mounting brackets are properly modified.

Dual pistons probably require more fluid... So, I would think that the master cylinder might need to be replaced too. Have you checked how much volume is required for the Original Setup compared to the Ford CF6000?

Also, verify the part# is for the vehicle you think it is.

I'm very interested in how this comes out so keep us updated.

I think the dual calipers would require more fluid to fill them, but the amount of fluid required to operate them should be about same, ASSUMING the pistons are the same DIAMETER.

Difference in piston area would be my biggest concern. The clamping/braking force of the pads on the rotor depends on the force of the pistons. Since pressure is defined as force per area (ie. lbs/sq. in) the caliper force results from the pressure of the brake fluid acting on the piston area.

At a given fluid pressure, a larger piston would develop more force but need more fluid to move it (brakes could lock up), while a smaller piston would develop less force and need less fluid to move it.(with weak brake action)

I think it would be important to see that the new caliper piston diameter is close to the original. If not, we might need a different master cylinder, or different boost pressure, and/or proportioning valve for rear brakes.

As for operating volume, if the pistons are the same diameter, it shouldn't be much different. Whether one piston takes up the slack or they each take up some, the combined piston travel is still the same as the slack so volume is the same (the total amount of fluid is same whether it goes to one piston or splits between both.)

It sure would be nice to find a good MCC caliper source! good luck

I haven't measured the pistons yet but I would guess they are about 20% smaller than the original single piston. Just estimating, the increased area of the two smaller pistons vs one larger is around 20%. Given the small amount of slack that is taken up when the brakes are activated, the overall difference in actual fluid volume required to displace the dual vs single pistons, on one axle, seems like it would be minimal. But I might be missing something. I haven't gotten far enough into this to even closely look at the master cylinder volume. I can only say that a previous owner invested some effort into this idea... Whether that effort was ultimately productive or futile, time will tell.

Does anybody know what the MCC spindles were based on? It is my strongly held opinion that MCC started with relatively "off the shelf" wear parts and fab'd a chassis around those parts. Knowing those base parts would be a huge step.

20% should be close enough to work fine with your master cylinder, etc. Hopefully you can get the caliper bracket to match up!

It would be great to find generic parts for the MCC chassis. Save a lot of folks (and you!) the hassle of tracking them down. We need to find some old timer who worked on all kinds of trucks back in the day... (takes one look and says "oh yeah, that's the same as the ones on a 1986 Duplex Gangwagon, etc...) Even if it matches to an odd part, at least you'd know what you're looking for.

I may be able to get some info on torsion bar adjustment. I'll post whatever I get.

This is one of the good points with the GM chassis. Parts are everywhere!

My brothers MCC has the inadequate brake system and the problem seems to be the smaller rotors. A check indicated the originals were made for a few years by Chevrolet and installed in a military duece and a half truck (2-1/2 ton) and that there were few made and none used later. MCC uses a larger rotor and calipers that he manufactures and the only drawback is the price, but he gets great reviews feom them has had them done. It's easy to make an adapter for the calipers, but hard to make the proper rotor as they are usually cast and machined.

Steve- right on, we need that guy for sure. My Duplex Gangwagon was a '79 & these parts look nothing like what I remember.

Tom is right, hanging a caliper is relatively easy... rotors are another story. I was hoping a mockup would tell me something about the intent for rotors with this "upgrade". I got four extra caliper brackets with the MCC, one had been cut and adapting brackets welded on; one was cut only; two are original. I may cut the modified one apart and tack it together (with correct offset) for a mockup. I'm curious where the previous owner (2 owners ago I think) found these parts and how the Ford calipers entered the equation.

The MCC rotors really don't look much bigger than the rotors on my 3/4 ton truck, that concerns me. I've pulled both front brakes apart now. The dust boots on both calipers are shredded. The pistons seemed to retract slightly with a c-clamp, so I think they were functioning. Haven't checked the back yet.

There are actually two master cylinders on the MCC.... One for the fronts and one for the rears.. There is plenty of room between the frame rails to work on them.... I rebuilt the front "Bendix Roto-Chamber" (we call master cylinder) on mine and there are pretty detailed pics of that job somewhere on this site (use the search function).... The low fluid indicator swith is resettable, you just need to manually reset it at the roto-chamber.... The resivoir for the fluid on that unit is extremely large and hold (guessing here) prob near a quart (each), I dont think the extra fluid needed would be a problem... I'd be concerened about the pressure you'll be putting on a different style caliper... I'm not sure but I'd think the only "porportioning valve" would be the size of the orifice in the roto-chamber... MCR (Motor Coach Restorations), speciffically Christopher, is very knowledgealble about the MCC brakes and he has the larger size rotors (and calipers) there at MCR (very pricey), contact info is also available on this site...

I've been able to complete my disassembly of the front brakes and steering. Going to replace ball joints and all eight tie-rod ends... ball joints are loose and tie-rod ends are tight. The bellcrank looks OK but I will rebuild it. The idler arm is loose, probably the main culprit causing the wandering issues (right upper ball joint was a contributor too, I suspect). I will rebuild the idler arm too. Got a chance to look closely at the master cylinders... they are huge. I had a long conversation with Christopher. One option he suggested is to increase the air pressure to the air assist. The other option is $4,300 for MCR's upgrade to 15 1/2 inch rear brakes (only). Too rich for my blood. I'm researching other options including the possible retrofit of the Ford calipers with ?? rotor. Will keep everyone posted.

Following up on this topic, I'm not sure how many of you MCC chassis owners are aware that brake calipers, pads and brake hoses are an off-the-shelf item from any well-stocked parts house. I got mine from NAPA and they were in-stock. The calipers are a common Bendix made for mediun-duty applications like the GM P30 chassis. Rotors are another story... they are not readily available unless you want to cough up $700 to MCR. I'm fortunate that my front rotors cleaned up OK. I'm also fortunate that my coach actually came with one extra rotor that is still at legal thickness. The min thickness is not stamped anywhere on the rotors and data is impossible to fine. According to Christopher at MCR the min thickness for my 1981 MCC rotors is 1.39". I can't say whether that is min thickness for all MCC rotors. Talking to Christopher at MCR and to Jim Black in Calif., both say the stock brakes are adequate. Christopher recommends an upgrade if you are towing. My personal opinion... although the rotor diameter seems a bit on the small side, they are one beefy ventilated rotor. I would think if properly maintained they would be fine. That's just one guy's opinion... and I haven't had the coach out yet with the new brakes, still have the rears to do and still putting the front end back together after collecting all of my parts. I can't get the coach in my shop, so I'm having to work outside in the lovely Pacific NW late fall weather. Next year is the year for a major shop expansion, and after that the MCC will be stored inside.

Has anyone considered changing these out to drum brakes? My Regency has drums with air power and they work great. In addition there are a number of heavy duty brake drum mfg's who make any size and type of drums. You might get a changover to a more standard and affordable mass produced product. Check Durabrake.com for one such company.

I brought up a similar question shortly after I bought my MCC and joined this forum. I was wondering about S-cam air brakes. The big hurdle I see is the 4-wheel independent suspension. Where do you mount the air cans? Tom, are your brakes full air, not air over hydraulic as originally outfitted?

I guess the answer is I am not sure. There are the tell tale air chambers at each wheel and I see no hydraulic reservoirs or bleeders, but perhaps Nick Cagle knows. Our coaches are sisters and apparently was just one coach between us on the production line. It is a Bendix System according to the manuals in the "Book".

Pretty sure that all Regencies after the MCC era from late 80s thru mid 90s on Gillig or Spartan chassis are full air systems. Every one I've ever looked at over the last 10 years was. And that's quite a few.
Please correct me if I'm wrong!
Where any other chassis brand used by Barth on their Regency models? The later 90s Regencies seem to all be on the Spartan Mountain Master frame.
Don