Sunday, December 20, 2015

40 mm master mods hydroboost adapter and changing stops

40 MM internals on top P30 below for size comparison.
Fabricated two piece spring retainer to allow more stroke on primary
   Recessed stop for more primary stroke, far as it could go without spring bind.
                               Before modification
                          Two piece retainer installed, original below.
                                       Two piece on the rod
            Primary spring not binding when on the stop.
   I wanted a 3.2 to 1 ratio but that would require new pistons. 3 to 1 worked OK.

 The bottom of the bore is not flat. Spacer makes up the difference that was put on the primary side.
               grooves go to the bottom to let any air out

Hydroboost being installed has an output stroke of 1.708"
 This is the 40mm master shown and it fits:

2001ChevroletC3500HDBase Cab & Chassis 4-Door8.1L 496Cu. In. V8 GAS OHV Naturally Aspirated
Doorman M630028

 Ours came from Rock Auto and I see them on Ebay too.

Sunday, December 6, 2015

Hydroboost gets a bore job

Opening up a hydroboost output end to accept a 40MM master cylinder. Going to use this in combination with a spacer. Not bored full depth so the spider that holds the output rod will still be usable.