Quote:
|
The service manuals I have found online do not show any third line like I have on my master cylinder.
|
Yes you must have that third brake line. The diagram in the previous post is a good one.
The inboard bore (in truck mounted position) is the
clutch master cylinder. It controls the clutch slave cylinder mounted on the belhousing.
The outboard bore, which is larger, is the
brake master cylinder and controls the brake slave cylinder which is mounted to the frame.
The third line is for the reservoir for the
brake slave cylinder. Note that the pressure in that line it is low (essentially zero) pressure.
So the reservoir in that casting mounted high on the firewall is for 3 things- the clutch master, the brake master, and brake slave cylinders.
As noted above, there are two different brake bore sizes- 1 1/8" and 1 1/4" . Measure your old to be sure because the books can be confusing. Measure the clutch bore while you're at it.
If everything else about your new master cylinder is correct, then adding that brass fitting for the third line will work. BTW It is a pipe thread going into the casting.