Dodge RAM TRUCK 1500 1995 Service Manual page 181

B R
M A S T E R C Y L I N D E R 5 - 1
M A S T E R C Y L I N D E R
INDEX
page
Brake Fluid Contamination . 10
Brake Fluid Level 10
Description . 9
Master Cylinder Application . 9
Master Cylinder Bleeding (On Bench) 14
Master Cylinder Cleaning and Inspection 13
Master Cylinder Disassembly and Overhaul . . . . . . 12
D E S C R I P T I O N '
BR models are equipped with a Delco, two-section
master cylinder assembly. Major components are the
aluminum cylinder body and a removable plastic res­
ervoir (Fig. 1).
The primary and secondary pistons are located in
the cylinder body. Grommets are used to secure and
seal the reservoir in the cylinder body. The reservoir
cover is equipped with diaphragm seal and is a snap
fit on the reservoir.
The cylinder body is equipped with a quick take-up
valve located in the primary piston inlet port (Fig. 1).
The valve provides an extra volume of low pressure
fluid during initial brake apply. Extra fluid volume
provides faster take-up of normal clearances in the
calipers and wheel cylinders.
MASTER CYLINDER SERVICEABILITY
The cylinder body, piston assemblies, reservoir,
grommets, seal and cover are all serviceable parts.
The take-up valve is the only non-serviceable compo­
nent. The valve is available only as part of a com­
plete cylinder body assembly.
MASTER CYLINDER APPLICATION
Three master cylinders are used in BR models. The
differences between them concern cylinder bore size
and fluid reservoir capacity.
• The master cylinder in 1500 models has a 28.6
mm (1.125 in.) bore.
• The master cylinder in 2500 and 3500 models has
a 31.8 mm (1.252 in.) bore.
Although the master cylinders used in 2500 and
3500 models have the same bore size, they have dif­
ferent piston stroke lengths and fluid reservoir ca­
pacities. Refer to Brake Fluid Level and Master
Cylinder Identification in this section for details.
Master cylinders and reservoirs must never
be interchanged. This practice will cause unsat­
isfactory operation and improper brake bal­
ance.
page
Master Cylinder Identification Codes 9
Master Cylinder Installation . . . . . . . . . . . . . . . . . . 15
Master Cylinder Reassembly . 13
Master Cylinder Removal 11
Master Cylinder Serviceability 9
Recommended Brake Fluid 10
PISTON
ASSEMBLY J9405-13
Fig. 1 Delco Master Cylinder
M A S T E R C Y L I N D E R IDENTIFICATION C O D E S
The master cylinder and reservoir are coded for
identification. Code letters are provided on the cylin­
der body and reservoir for proper component match­
ing.