SWIFTY

any one no what would cause the brake pedal to be solid brakes still work as does the abs and no lights are on the dash. you have to press realy hard and it only moves abit.

thanks













(spelling)

.Ross.

iTrader: (2)

Vacum pipe come off? Have you still got the vacum assistance?

Moonstone Steve.

iTrader: (2)

Mine was the relay under the dash when this happened.

Steve

carl/saff

which relay mate, cheeRS carl

dojj

iTrader: (3)

there are 3 of them
either 2 green and one purple or 1 purple and 2 green ones

should be under the passenger side glovebox area by the transmision tunnel on a littl ebrakcet

whats happend is that the pump has pumped up tpp mush pressur einto the system so it needs releasing

it might need a new pressure switch though, in which case, you migh tbe beter off looking for a whole new pump assembly as the fluid tend to corrode the innares and they strip the threads from both the casing and the valve

carl/saff

how do you know which relay has failed ,as pedal goes hard and car will grab under breaking !!!! what does each relay do ? cheeRS carl

carl/saff

also does the abs system share power feeds with the fans ? got a wiring diagram ? could this also be the abs sensors ? thanx carl

dojj

iTrader: (3)

the abs is stand alone mate, shares nothing other than the ignition feed from the fuse box with the rest of the cars wiring and where it plugs onto the battery

you just need to swap these relays over and se if the problem goes away or not

SWIFTY

just had a quick look and i have 1 yell 1 green and 1 purple relay and could only swap 2 as one has 5 pins the other 2 have 4, and it didnt make no diffrance to mine. but what i did notice is that if i pumped the pedal when the pump was still running it was softer and i could push the pedal down more, then it got harder and harder till the pump stoped.

dojj

iTrader: (3)

you shouldn';t have a yellow relay there mate

SWIFTY

all the relay coulours match the plugs they are in.
does the coulour make a diffrance then???

carl/saff

was thinking why 3 relays ,what does each one do ? cheeRS carl

dojj

iTrader: (3)

powe power and something else, but not sure what unti i get home and look the book up with the stuff in it

TiB

iTrader: (1)

There is also a fuse under there with the relays.. my bet is that has blown or come out.

SWIFTY

i looked at the fuses when i looked ant the relays they seemed ok

TiB

iTrader: (1)

Check the main power plug is clean and connected to the pump properly too.

carl/saff

tried a purple relay out of another saff[with working abs system] same part no as mine and my abs light came on and break fluid level warning light came on aswell[mine has never done this].will go to fords and get 3 new relays .

boXXer

hi mate, did they sort the problem? i have a similiar issue

carl/saff

NO !!!! Put new green reley in from Ford , 2x purple releys are on back order . abs sensors tested range .9 to 1.1 all four so they seem OK. Pluged in snap-on fault code reader and melted my wiring loom to the abs [ lucky didnt set my saff on fire] some twat had back wired one of the relays to put out the abs light . getting a new abs wiring loom / ecu got new sensors already but mine seem ok [so will keep as spares] what a carry on !!!!!

botters

iTrader: (2)

had this once with my xr4x4 caused by sitting in traffic for an hour with my foot on the brakes....DOH!!! pedal went rock solid and took serious effort to stop allthough luckily after i got home (and felt the pump and servo which were damn near glowing lol!) after letting it cool down all was fine. this probably wont help you with your fault but may help other sierra abs owners from doing the same dim witted thing i did lol!