[DeTomaso] Fun w/ brakes and questions

[JDeRyke at aol.com]

Konrad, if you can locate a copy of the August 2002 POCA News, I went thru 
a street-rebuild of all 4 calipers, with illustrations. You're right- its 
not difficult nor do you need special tools or an assistant. It IS incredibly 
messy and will take most of one Saturday to do all 10 pistons. The pistons 
collect varnish from not changing brake fluid each Spring, and hang up in the 
bores. All thats needed is to check for leaks, then force one piston at a 
time out, wipe it clean with a mildly abrasive Scotch-brite pad and 
reassemble. If the slightest leak is seen, the seal inside the casting is a single 
square o-ring and replacements are available from the vendors. 
The only bad thing is, some caliper leaks are not fixable by replacing the 
seal. European brakes are made with nickel-plated mild steel pistons. Which 
rust in old water-loaded brake fluid (yet another reason to change fluid 
each Spring!) A rust-pitted piston cannot be re-sealed. U.S brakes- including 
Wilwoods- use stainless steel pistons and do not suffer this problem. I know 
of no replacements for these Girling pistons. You can strip the plating, 
smooth the steel and re-plate a pitted piston at vast cost, or make duplicates 
from stainless bar stock if you're handy. Most guys look around for a 
useable used caliper from someone who'se upgraded his brakes. Note there are two 
different sized pistons in front brakes; the trailing-edge piston is smaller 
than the leading edge piston- a racing feature from Dallara, I suspect.
While you're digging around in there, I'd replace the stock lines with 
stainless AN lines. Best is dash-3 which are smaller diameter and thus react 
faster to pedal force, but dash-4 are common, cheaper and work better than 
stock rubber. I also recomment Speed-bleeders on all bleed ports including the 
clutch slave, to save from having to beg a helper to spend his/her Saturday 
sitting in the car pumping the pedal for you. Finally, I recommend 
Porterfield R-4-S pads front & back. They stop the car quicker than stock pads and 
last nearly as long. They are not 'racing' pads- they need not be heated up to 
work wonderfully well. Good luck- J Deryke