Downloaded from www.Manualslib.com manuals search engine Slacken pressure regulator bleed screw.
Put manual height control in /VII. position
Disconnect front left-hand cylinder supply
pipe ( 1 ) from 3~woy union (2 ).
Plug 3-way union opening using plug E.
Repeat test as described in preceding parograpb.
If the front left suspension cylinder is defective
replace 01 repair it.
Remove plug E.
Fit supply pipe ( 1 ).
If after testing the front height corrector and the
left-hand front suspension cvlinder, the drop in
pressure persists, the front right-hand cylinder
is defective.
Replace or repair it. Il.
Checking the rear suspension :
Slacken pressure regulator bleed screw.
Put manual height control in IOU pnsi!ios,
Remove plug E.
Connect rear suspension supply pipe (?) to
safety valve.
Disconnect rear brake supply pipe (4) from
brake valve.
Plug oriilce of pipe using plug D.
Tighten pressure regulator bleed screw
Place manual height control in aorwnl rrruniug
posilio,,.
Proceed as for test of front suspension.
12. Slacken pressure regulator bleed screw.
Disconnect 3-way union B together with pressure
gauge A and pipe C.
Fit connecting pipe of safety valve to pressure
regulator.
Tighten pressure regulator bleed screw.
Downloaded from www.Manualslib.com manuals search engine OPERATION No MA. 450-00 : Ch nrnclcrislics ortd sp~~c-i~l (c~c~trlrc>s 01 the hokiug S SI~IN Op. MA. 450.00 5
A brake pressure limiter is fitted to the rear braking system on Estate vehicles.
Its object is to vary the maximum
pressure in the rear braking system as a function of the load imposed on the rear suspension and the pressure in
the front braking system. It is secured horizontally on the front subframe, behind the safety valve.
L 45-6
Rear brakes Air-chamber
A
Front brakes
Rear brakes Air-chamber
A A --
7 Front brakes OPERATION
* I
f Vchtclcs - ‘I/]‘,?(, i
The brake pressure limiter consists mainly of a
slide-valve, the positions of which allow or do not
allow the supply of fluid under pressure from the
brake valve to the rear brakes.
The ends of this slide-valve are submitted to the
action of two forces
- Force F
exerted by the fluid under pressure in
the rear suspension.
= Force R
exerted by spring ( 1 ) and increased by the
value of force Fl
exerted by the front brake fluid
pressure during braking action.
a) \‘~~I~i~-/~~s irt Ilte t( lorl r /tr,.silioti f t/o /trc~.s.surc’ )
Under the only force R,that of the spring. slide-valve
is in the position indicated in figure 1. The fluid
cannot pass from the brake valve to the rear brakes,
( and vice-versa ).
Force
F exerted by the rear suspension pressure
is greater than Force R
exerted by the sprinq.
The slide-valve is in the position indicated by
Figure 2. which allows flow of fluid from brake
valve to rear brakes ( and vice-versa ).
c ) Vvhiclc il2 ntotior/. rr,ith 111~’ broke pednl ncl~~fit~~c/ :
Fluid from the front brakes exerts a Force Fl
which is added to Force R exerted by the spring.
When these two forces are smaller than force F,
slide-valve is in position shown in Figure 2.
The rear brakes are supplied.
When these two forces are greater than Force
F,
slide-valve is in the position shown on Figure 1.
The rear brakes are not supplied.
NOTE Fl
+ R -b F is true, when the pressure
in the front brakes + 28 bars ( 406 psi ) becomes
greater than the’pressure in the rear suspension.
When F
increases, Fl increases. Consequently,
maximum pressure in the rear brakes increases.
In order to avoid a sudden cut-out of the supply
to the rear brakes, a ball-valve slows the flow
of liquid from the front brakes. The action of this
valve is increased by the fact that an air-bubble
trapped in its chamber, secured at the rear of the
front subframe upper.crossmember on the L.H. side,
has to be compressed. Once the slide-valve has
started moving, the supply of fluid is not slowed
down, and it then flows through the by-pass channel.
