[barny]

We recently lost the brakes on our '98 4.6hse, well to a point, the pedal goes about half way down and needs a **** hard push to get it to actually stop. It appeared to me that the accumulator was at fault so ordered and replaced, but i seem to have lost my brake pressure pump.

I can bridge the pump relay and the pump will run continuously and re-pressurise the system but whatever controls the pump relay isnt sending the correct signals.

Heres a list of things i've done so far - in no particular order!

Checked fuses, been caught out with this many times `)
Replaced the accumulator as at the time the pump was working ok
Pressure and vacuum bled brakes (not the correct way as found on this forum)
Bridged the relay to check the pump works ok
Checked both relays for correct operation
Checked fuse box for damage or burn marks - looks kinda new
Checked continuity of wiring for relays, pump and pressure switch
Carried out a confusing ohms test on the pressure switch, not sure if its conclusive tho

I'm really stuck on this, any ideas clues pointers ramblings ...... anything at all please post up :lol:

 

[JeremyD]

I am taking a guess here but would say that if the relay is fine (the only black one in the box) and the pump runs with 12v applied then its the pressure switch how you test it or bypass it to test I am not sure. I do know of one failing already

 

[barny]

I am taking a guess here but would say that if the relay is fine (the only black one in the box) and the pump runs with 12v applied then its the pressure switch how you test it or bypass it to test I am not sure. I do know of one failing already

Im thinking along those lines but finding the correct data is tricky!

 

[viperover]

Seems to be your pressure switch, sadly they are not available loose yet.

i would refer this repair if you are not a technical guy to someone who knows what to do like me but we're miles away like really far away

 

[barny]

Quick update, no progress as such but a secondhand pump/acc/switch assembly will be with me in the next few days

Fingers Crossed `)

 

[barny]

Sorted! New pump assembly fitted with new accumulator and hes back up and running. The old pump worked fine so its gotta be the switch on ours ...

 

[viperover]

Its always that darn switch...... :twisted: