The problem with the Budd 4-piston brakes (or opposed piston brakes) is that Chrysler was the only company that used them, They were not a Chrysler design. The Budd brakes were used only on Chrysler's C bodies - Fury, Polara, Monaco, Chrysler (all 1966-68) and Imperial (1967-69). That short timespan works against the availablity of parts, too. Also, the pistons in Budd opposed piston disc brakes are the only pistons with a piston guide (that little 'finger' on the back). And the 4-piston design was the system used by virtually all manufacturers at that time. Chrysler's B bodies (Belvedere, Coronet, Charger) used Bendix opposed piston brakes 1966-70. AMC, senior Buicks, Cadillac and Eldorado also used Bendix oppposed piston brakes at some time in the late 1960's. Chrysler's A body cars (Valiant and Dart - 1965-72 / Barracuda 1965-69) used Kelsey-Hayes opposed piston brakes. Kelsey-Hayes also supplied that design to Ford, Mercury, Lincoln and Oldsmobile Toronado during the late 1960's. The fourth manufacturer of opposed piston brakes was Delco-Moraine, a GM subisidiary, Their brakes were used on various GM lines in the late 1960's, including Corvette through 1972. All 4-piston systems had fixed position calipers. Floating calipers came with the single piston disc brakes, which were built by Kelsey-Hayes and Delco-Moraine. Chrysler replaced its three versions of the opposed piston brake with Kelsey-Hayes single piston units. The only manufacturer not to use a 4-piston opposed piston disc brake was Studebaker. They used a dual piston, fixed caliper brake built by Bendix based on a British Dunlop design. They were introduced in the spring of 1962 on the Avanti and offered on all models starting with the 1963 model year. The interesting point on the Studebaker system is that cars with drum brakes had dual master cylinders (except Standard and Challenger series), while the disc brake cars had a single master cylinder. Bill Vancouver, BC ----- Original Message ----- From: "Peter Engel" <peter.engel@xxxxxxxxxxx> To: <mailing-list@xxxxxxxxxxxxxxxx> Sent: Wednesday, January 15, 2003 7:25 AM Subject: IML: 69 Imperial Budd photo -- revised > First of all, I think that the straight-on shot of the Budd brake setup > may have faked viewers out. Here's a different shot that clearly shows > that the rotor and hub are separate parts: > > http://www.bos-engel.com/Imperial/rotor.jpg > > Secondly, I guess I should have said merely that the Budd system is a > problem area for many owners. When you have problems with it, > especially rotors, the repair job will be expensive. > > I don't think that Chrysler released a brake system that was defective > or worked poorly, especially on their flagship models. The problem > seems to be that the systems don't age well, especially on cars that > have sat for a long time or are driven infrequently. In short, 8 > pistons provide 4X as many leak/moisture entry points as 2 pistons. > Also working against the system is the fact that the rotors are quite > thin even when new and they shouldn't be "cut." > > Mercedes Benz uses/used a nearly identical caliper on their high end > models, and MBZ cars have stunning braking ability. I recently worked > on a beautiful 1988 560SL and it had the 4-piston, fixed-caliper brake > system. On that car, one of the pistons in the right caliper had seized > and created a real mess. The brake rotor was quite discolored and > caliper parts got hot enough to melt the piston dust boots. Repair > parts, while easily available from a MBZ dealer were probably more > expensive than Budd parts! > > So I'm not a Budd hater! I still believe, however, that it is the > Achilles heel of the 69s. > > Pete in PA > Rebuilding the Kelsey Hayes 4-piston disc brake setup for his 72 Duster > Twister > >