User's Manual
6
FIGURE 10 - BP-R1
™
BOBTAIL BRAKE PROPORTIONING RELAY VALVE
10
30
31
13
14
11
12
1
4. Connect the tractor service and emergency “glad
hands” (hose couplings) to hose couplings that have
been plugged, or alternatively, to a trailer. Build the trac-
tor system air pressure to governor cut-out and make 4
to 5 full brake applications. Check the air fi ttings at the
BP-R1
™
valve for leakage. Tighten as needed.
5. With the trailer supply valve (dash control w/red oc-
tagonal button) and system park control (dash control
with yellow diamond button) activated for tractor/trailer
operation, apply, hold, then release the brakes several
times varying the application pressures while watch-
ing the reaction of the gauges installed on the BP-R1
™
valve. Check that a prompt application occurs and that
it can be held then promptly released.
4
5
6
7
8
9
3
35
15
17A
18
23
20A
22
24
25
27
29
33
28
34
32
36
37
2
BODY .........................................1
VALVE COVER ............................... 2
RETAINING RING ............................3
EXHAUST COVER ...........................4
O-RING ........................................5
O-RING ........................................6
VALVE SPRING ..............................7
VALVE RETAINER ...........................8
VALVE ASSEMBLY ..........................9
CAP SCREWS .............................10
O-RING ..................................... 11
O-RING ......................................12
RELAY PISTON ............................13
RETURN SPRING .........................14
RETAINING RING ..........................15
DUST SHIELD (IF FITTED) ...............16
EXHAUST PISTON (ORIGINAL STYLE) . 17
EXHAUST PISTON (NEW STYLE) ....17A
EXHAUST PISTON O-RING .............. 18
EXHAUST DIAPHRAGM (IF FITTED) .... 19
SERVICE PISTON (ORIGINAL STYLE -
REQUIRED O-RING 21) ..................20
SERVICE PISTON (NEW STYLE -
DOES NOT REQUIRE O-RING) ........20A
SERVICE PISTON O-RING (IF FITTED) 21
SPRING ..................................... 22
SPRING CAGE .............................23
BLEND BACK PISTON ....................24
O-RING ......................................25
O-RING ......................................26
O-RING ......................................27
PROPORTIONING PISTON ...............28
O-RINGS ...................................29
RETAINING RING ..........................30
O-RING .....................................31
INLET VALVE SEAT .......................32
INLET VALVE ...............................33
VALVE SPRING ............................34
SEALING RING ............................35
EXHAUST COVER SCREW ..............36
EXHAUST COVER .........................37
Note:
Early models
used a
Diaphragm(19),
Dust Shield(16)
Service
Piston(17), and
o-ring(21)
26
15
17
19
16
1820
21