Dodge Sprinter 2006 Manual page 787

VA
(3) Du r in g r oa d t est , m a ke n or m a l a n d fir m br a ke
st ops in 25-40 m ph r a n ge. Not e fa u lt y br a ke oper a -
t ion su ch a s low peda l, h a r d peda l, fa de, peda l pu lsa -
t ion , pu ll, gr a b, dr a g, n oise, et c.
(4) At t em pt t o st op t h e veh icle wit h t h e pa r kin g
br a ke on ly a n d n ot e gr a b, dr a g, n oise, et c.
PEDAL FALLS A WA Y
A br a ke peda l t h a t fa lls a wa y u n der st ea dy foot
pr essu r e is gen er a lly t h e r esu lt of a syst em lea k. Th e
lea k poin t cou ld be a t a br a ke lin e, fit t in g, h ose, or
ca liper /wh eel cylin der. If lea ka ge is sever e, flu id will
be eviden t a t or a r ou n d t h e lea kin g com pon en t .
In t er n a l lea ka ge (sea l by-pa ss) in t h e m a st er cylin -
der ca u sed by wor n or da m a ged pist on cu ps, m a y
a lso be t h e pr oblem ca u se.
An in t er n a l lea k in t h e ABS or RWAL syst em m a y
a lso be t h e pr oblem wit h n o ph ysica l eviden ce.
LOW PEDAL
If a low peda l is exper ien ced, pu m p t h e peda l sev-
er a l t im es. If t h e peda l com es ba ck u p wor n lin in gs,
r ot or s, dr u m s, or r ea r br a kes ou t of a dju st m en t a r e
t h e m ost likely ca u ses. Th e pr oper cou r se of a ct ion is
t o in spect a n d r epla ce a ll wor n com pon en t a n d m a ke
t h e pr oper a dju st m en t s.
SPONGY PEDAL
A spon gy peda l is m ost oft en ca u sed by a ir in t h e
syst em . H owever, t h in br a ke dr u m s or su bst a n da r d
br a ke lin es a n d h oses ca n a lso ca u se a spon gy peda l.
Th e pr oper cou r se of a ct ion is t o bleed t h e syst em ,
a n d r epla ce t h in dr u m s a n d su bst a n da r d qu a lit y
br a ke h oses if su spect ed.
HARD PEDAL OR HIGH PEDAL EFFORT
A h a r d peda l or h igh peda l effor t m a y be du e t o
lin in g t h a t is wa t er soa ked, con t a m in a t ed, gla zed, or
ba dly wor n . Th e power boost er or ch eck va lve cou ld
a lso be fa u lt y.
PEDAL PULSA TION
P eda l pu lsa t ion is ca u sed by com pon en t s t h a t a r e
loose, or beyon d t oler a n ce lim it s.
Th e pr im a r y ca u se of pu lsa t ion a r e disc br a ke
r ot or s wit h excessive la t er a l r u n ou t or t h ickn ess va r i-
a t ion , or ou t of r ou n d br a ke dr u m s. Ot h er ca u ses a r e
loose wh eel bea r in gs or ca liper s a n d wor n , da m a ged
t ir es.
NOTE: Some pedal pulsation may be felt during
ABS activation.
BRAKE DRAG
Br a ke dr a g occu r s wh en t h e lin in g is in con st a n t
con t a ct wit h t h e r ot or or dr u m . Dr a g ca n occu r a t on e
wh eel, a ll wh eels, fr on t s on ly, or r ea r s on ly.
Dr a g is a pr odu ct of in com plet e br a ke sh oe r elea se.
Dr a g ca n be m in or or sever e en ou gh t o over h ea t t h e
lin in gs, r ot or s a n d dr u m s.
Min or dr a g will u su a lly ca u se sligh t su r fa ce ch a r-
r in g of t h e lin in g. It ca n a lso gen er a t e h a r d spot s in
r ot or s a n d dr u m s fr om t h e over h ea t -cool down pr o-
cess. In m ost ca ses, t h e r ot or s, dr u m s, wh eels a n d
t ir es a r e qu it e wa r m t o t h e t ou ch a ft er t h e veh icle is
st opped.
Sever e dr a g ca n ch a r t h e br a ke lin in g a ll t h e wa y
t h r ou gh . It ca n a lso dist or t a n d scor e r ot or s a n d
dr u m s t o t h e poin t of r epla cem en t . Th e wh eels, t ir es
a n d br a ke com pon en t s will be ext r em ely h ot . In
sever e ca ses, t h e lin in g m a y gen er a t e sm oke a s it
ch a r s fr om over h ea t in g.
Com m on ca u ses of br a ke dr a g a r e:
• Seized or im pr oper ly a dju st ed pa r kin g br a ke
ca bles.
• Loose/wor n wh eel bea r in g.
• Seized ca liper or wh eel cylin der pist on .
• Ca liper bin din g on cor r oded bu sh in gs or r u st ed
slide su r fa ces.
• Loose ca liper m ou n t in g.
• Dr u m br a ke sh oes bin din g on wor n /da m a ged
su ppor t pla t es.
• Mis-a ssem bled com pon en t s.
• Lon g boost er ou t pu t r od.
If br a ke dr a g occu r s a t a ll wh eels, t h e pr oblem
m a y be r ela t ed t o a blocked m a st er cylin der r et u r n
por t , or fa u lt y power boost er (bin ds-does n ot r elea se).
BRAKE FADE
Br a ke fa de is u su a lly a pr odu ct of over h ea t in g
ca u sed by br a ke dr a g. H owever, br a ke over h ea t in g
a n d r esu lt in g fa de ca n a lso be ca u sed by r idin g t h e
br a ke peda l, m a kin g r epea t ed h igh deceler a t ion st ops
in a sh or t t im e spa n , or con st a n t br a kin g on st eep
m ou n t a in r oa ds. Refer t o t h e Br a ke Dr a g in for m a t ion
in t h is sect ion for ca u ses.
BRAKE PULL
F r on t br a ke pu ll con dit ion cou ld r esu lt fr om :
• Con t a m in a t ed lin in g in on e ca liper
• Seized ca liper pist on
• Bin din g ca liper
• Loose ca liper
• Ru st y ca liper slide su r fa ces
• Im pr oper br a ke pa ds
• Da m a ged r ot or
A wor n , da m a ged wh eel bea r in g or su spen sion
com pon en t a r e fu r t h er ca u ses of pu ll. A da m a ged
fr on t t ir e (br u ised, ply sepa r a t ion ) ca n a lso ca u se
pu ll.
A com m on a n d fr equ en t ly m isdia gn osed pu ll con di-
t ion is wh er e dir ect ion of pu ll ch a n ges a ft er a few
st ops. Th e ca u se is a com bin a t ion of br a ke dr a g fol-
lowed by fa de a t on e of t h e br a ke u n it s.
BRAKES - BASE 5 - 3