rasheed
Well-Known Member
My thanks to ALL who offered their advice and experience in helping me diagnose this!
Aw don't mention it mate. Just paying it forward. This forum has gotten me out of a tight spot many a time.
You do have to sometimes have wonder just where these people get their prices from. £277.00 plus Vat is seriously over the top for something that probably takes less than £30.00 to make.
Datatek
Well-Known Member
It's just a pressure switch FFS, probably knocking them out in China at tuppence a bucket full
It's just a pressure switch FFS, probably knocking them out in China at tuppence a bucket full
Yeah Keith just so. I was reluctant to put a lower price estimate, but you are more than likely nearer the truth than i was.
Years ago i did a tour of the Longbridge car plant. In the gearbox shop they were making first motion shafts for one of their vehicles that cost, if scrapped £9.70. That included making the shaft cutting a gear and laser welding them together. All done on automatic machines. Try buying one for anything like that price.
If it's the main switch it is quite a complicated three pole unit, with differing switching according to pressure, not just an on off switch. Look at the diagrams. Reference Z 104. Never the less it's way over the top price wise in my view.
Last edited:
Clarky130
New Member
I couldnt find the original Wabco part number - that was one of the avenues I looked into.
Wasn't that in one of my links?
Clarky130
New Member
Not that I could see...
Just discovered I can get the ABS light to go out if I 'manually' run the pump long enough... So at least part of the switch is working. Rigged a lead with a switch on the end to ground the pump relay, so I can drive it if I absolutely have to. My replacement switch from Emmotts should arrive tomorrow, along with a new accumulator - thought I might as well change that out as well whilst I have the brake system 'open' - saves me having to do the ball-aching bleed procedure twice!
I had the same problem turned out to be the ABS pressure switch sticking what I did was to run a wire from the neg side of the battery to the black and yellow wire on the back of the pressure switch this made the pump run constantly which eliminated something wrong with the pump itself so I changed the pressure switch and problem solved
Do you have a source for the pressure switch other than taking one off an old ABS pump?
Clarky130
New Member
Unfortunately not... I was unable to find one. Even if I could, they seem prohibitively expensive.
Clarky130
New Member
SUCCESS!! ...or at least it seems...
Switch arrived from Emmotts today. Got the old one out in-situ... It has 36mm flats on it, but not enough clearance between the switch and pump bodies to get a big socket on it. I just about managed to get it initially loosened with a Viscous Fan spanner, but then had to undo the pump mounts to move it around and get enough of a turn on it to remove it completely. Be aware that the switch body is milled Aluminium and is easily damaged by a steel spanner! Had shedloads of brake fluid come out, so a small thin tray of some sort underneath it would have been a good idea... The absorbent cloth I stuffed under there was quickly overwhelmed! Thankfully, the brake fluid followed a path that took it away from the top of the air spring, hoses, anything rubber, etc so hopefully I got away with it... Just had to thoroughly clean it off the bodywork.
Now, pump runs as soon as the ign is turned on, pressurises the system and stops after a seemingly sensible time. Brake pedal is nice and firm too. Won't get a chance to road test it until the Nagger get back from work... Not too keen on having the Clarkylets in the car until I've proven the brakes work!
Switch arrived from Emmotts today. Got the old one out in-situ... It has 36mm flats on it, but not enough clearance between the switch and pump bodies to get a big socket on it. I just about managed to get it initially loosened with a Viscous Fan spanner, but then had to undo the pump mounts to move it around and get enough of a turn on it to remove it completely. Be aware that the switch body is milled Aluminium and is easily damaged by a steel spanner! Had shedloads of brake fluid come out, so a small thin tray of some sort underneath it would have been a good idea... The absorbent cloth I stuffed under there was quickly overwhelmed! Thankfully, the brake fluid followed a path that took it away from the top of the air spring, hoses, anything rubber, etc so hopefully I got away with it... Just had to thoroughly clean it off the bodywork.
Now, pump runs as soon as the ign is turned on, pressurises the system and stops after a seemingly sensible time. Brake pedal is nice and firm too. Won't get a chance to road test it until the Nagger get back from work... Not too keen on having the Clarkylets in the car until I've proven the brakes work!
jamesblake
Active Member
Well done Paul!!
U seem to be doing the same as me......very slow total rebuild!!
Give us a few more months and we could combine cars and have a brand new P38!!!
U seem to be doing the same as me......very slow total rebuild!!
Give us a few more months and we could combine cars and have a brand new P38!!!
