cossirob

My cosworth has been playing up like a right bastard lately miss firing and so on but now my brake pedal has gone rock solid so I cant road test it to sort the misfire.

Iv traced the problem back to the relay and basically im getting power from the battery, im getting an ignition power and if I put a live to the pump feed it kicks in. when I earth the relay out the pump kicks in but it wont stop until I remove the earth iv put on. This make me think that the earth for the relay must be switched by some sort of pressure swith on the pump itself. But to be honest im crap with electrics and I could be totally wrong! Lol

Can anyone tell me how the relay is controlled? Am I right in thinking there could be a faulty swith on the pump?

cossirob

Iv traced the problem back to the pump... I think lol. The earth trigger for the brake pump relay is a brown/black wire that goes into the 5 pin plug on the pump, when I tap into that wire and earth it to the car the pump kick in but again wont stop pumping until I remove my earth wire.

does anyone know if I can unsrew that 5 pin sensor and replace it or is time for a new pump? I have tried to unscew it but its awkward to get to and I really dont wanna replace the lot because iv recently had the engine out and bay painted

pauloopnorth

Any update on how you sorted this mate

Caddyshack

I have a few spares if you want to try, I am only up the A3 near GRAYSHOTT tunnel.

grcossie

I have changed a few pressure switch, when they got this problem. You can use switch from Scorpio

TheRebuild15/16

Have you checked the fuse for accumulator on the ABS?

Barons knight

hi i have the same problem pedal just solid and no boost but the abs pump is running could it be the pressure switch problem is where to get one ?

grcossie

I have used pressure switch from Granada or Scorpio as it`s named here. Have done this on a couple of Cosworth`s

pauloopnorth

Seems to be the same switch used in the Range Rover P38 too
When i had this problem i had to replace the whole pump as it would not stop pumping
and was getting seriously hot to the point of smoking due to the motor constantly running whenever the car was turned on

pauloopnorth

https://www.ebay.co.uk/itm/Range-Rov...4Xo:rk:29:pf:0

martysmartie

iTrader: (1)

The fact the pump is running and you have no assistance means it is not getting unto pressure, hence you have no assistance.

This means there is a leak somewhere, a likely culprit is the the accumulator (or 'sphere' as it's affectionately known) which forms part of the M/C.

Martin

Barons knight

Hi Martin
Many thanks for your comments and i have given it a try with a replacement second hand accumulator from a dealer but still no go and when i contacted him again he said perhaps it did not have any gas in it you just can not win so he will change it for me if i bring the car down to him only 500 kms away
Regards
Richard

Barons knight

Hi Everybody
i am still having brake problems with the Cosworth have now fitted another accumulator and still no go the supplier tells me there is no gas in them until the pump gets up to pressure which never happens so i am now wondering if it is a faulty pump as it runs non stop but still no pressure.
Biggest problem is where to purchase a replacement pump they are unknown in New Zealand but i will be in the UK later this year all being well
Any ideas of a supplier who my have one would be appreciated
regards
Richard

scrotenz

Hi, try lodge auto center in Hastings if you havent. Theyve been great with assistance over the ph with me and my mechanic when I had brake issues. They may have the parts needed to. Otherwise I've purchased from Gary Bell quite often also which you can find him in all the cosworth groups on FB. Hope you get it sorted.

4x4kiwi

Hi Richard

You have Private Message with my phone number.

Cheers
David

Rodge.

Old thread I know but does anyone have a link for the pressure switch?

thanks