Need to replace the Master Brake Cylinder. Apparently the brake master cylinder and booster are after market.

Does anyone recognise it from the pics below?
Point me in the right direction??


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Original Post
That looks like the GM booster and master that Byars sells. If it is, there should be a big "dent" in the fender well on the left side of the booster. The booster on the firewall side had the studs removed and repositioned to fit the Pantera. I'm not sure what year/model the master fits.

Lui, my GM/Byars power booster was happily rebuilt by Bob Byars in CA for the cost of the part when it cracked a plastic air valve on the pedal side after 2 yrs (which may have been my own fault). I'd call him first if your unit has problems. A stock 4-bolt GM will likely not bolt into a stock 3-bolt Pantera, and changing the booster bolt pattern requires the entire new assembly be torn down for stud welding. Byars also gold-alodines the finished assembly for a professional look.
FWIW, a Byars-modified booster fits Pantera Ls without dents but early cars did need some 'hammer-massage' to fit slightly larger diameter booster cans. I had trouble with a factory Gr-3 installation that also uses a bigger booster, in a pre-L. But since your Pantera is apparently a late wide-body with potentially everything diferent, dunno what might be a true bolt-on. Keep us informed when you sort it out.
Thanks all for your help.

I got in touch with Bob (Precision Proformance), and purchased the master brake cylinder from him.

Bob did confirm that it's a GM Master as per some of the previous advice. For prosperity I like to know where "other" make parts used on my Pantera come from.

Whilst I could of gotten it a bit cheaper elsewhere, Bob was helpful over the phone, and seeing as this is the first time I'm replacing the master brake cylinder and the fact that I'm in Australia it made sense to by from Bob just in case there are any issues that arise whilst replacing it.

Plus I'm it taking for granted that Precision Proformance are a trusted Pantera parts retailer and it gives me more confidence buying from overseas.

Bob also assured me that this is a "new" unit not "remanufactured" as by Cardone's.

I've still got the booster in, as the pantera is drivable. It just leeks back into the reservoir.

Once out I'll take some pictures with the brake master cylinder out for prosperity. I should get the replacement in about 8-10 days.

Thanks all for your help.
Lui, FWIW, the Byars/GM brake master cyinder has a built-in 'residual pressure valve' under the front brake fluid reservoir. Do NOT run aftermarket r.p. valves along with this part or weird things will happen when braking. The theory is, by keeping 2 psi or so in the front calipers & lines, the pads are kept closer to the discs for faster brake response. They also cause faster wear of the pads, heat the rotors & pads a bit and somewhat slow the car's speed all due to brake drag. It is easily removed if you like- a thick black plastic washer with a small spring & ball-check.

Another thing- a manual proportioning valve in the rear brake line can be used to balance your braking system front-to-rear. I use a Kelsey-Hayes valve that was stock on older Corvettes, but there are many others sold by Jegs, Summit and elsewhere. Valuable if you've changed many things in the brake system or even increased tire sizes much. The GM booster alone is not enough of a change to warrant it, though.
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