Calling All Brake Gurus

[fflyingdog]

I have found the black variant ( GM part number) last spring in the US. Got three pcs. which have been sold already, but after that my supplier was not able to locate this switch anymore. I am sure that there are still some out there,sitting on a shelf in some workshop, but unless these shops are linked to a parts trader online system, they will probably still lie on those shelves when our cars are dust.

I hope to find an alternative in europe some time soon....

And yes, 99% of the time it is this stupid switch ! I spent 2 years doing trial and error replacements to narrow it down....

Will be really interested when you do manage to find a europe supplier of these infernal pressure switches.

Cheers

Nick S4s

[karluk29]

does anyone know the gm part number?

[lemoncurd]

Karl,

I think the GM Part number for the pressure switch is: GM 88927270 (AC Delco 18M873)

Ben

[lotus4s]

Good luck finding any here in the US. We've had the same problem locating a switch also as all the major GM parts suppliers don't have it and GM has discontinued it.

[karluk29]

well looks like a nightmare as i have just read on a firum from 2004 that the pressure switch in the states is still $449.00 which is insane, this bloke back in 2004 luckily got it trade and got 50% off the price.

so looks like unless someone can make a copy we are screwed

[Bibs]

You can get them from Lotus, it's just that they are pricey as they need to buy the whole unit to take the switch out. I'm not sure if they have any left, let me know if you want me to ask and I'll see what the stock levels are.

[karluk29]

yeah its the price thats the issue with everyone i think bibs, even my garage guy was shocked, he said oh its ok will be about

Edited February 8, 2008 by karluk29

[Jonathan]

At that cost I'd start looking at different options.

The Gt2 was going to have the braking system removed from it and a twin cylinder put in for direct braking (much like the S1 Elise which was the best car for brakes I've ever driven) - I was going to port that over to the GT3 when the ABS system finally gave up (if it gives up).

I know ABS is important, I'd rather have it than not but in a fair few circumstances ABS can be an ass - Esprits coped with it fine up until the later cars, so if you're comfortable with it I dont see why you shouldn't go that route.

Only had ABS cut in 3 times on any car. Twice was the Probe (someone cut me up and the other was on an Icy hill !) and the Esprit when the front wheel went over a manhole cover whilst HEAVY brakings - the ABS said "oh, locking up ? I'll dump ALL the calipers then...." how I stoped before the roundabout I'll never know because your tendancy is to just plant the brakes which makes it worse !

Copy from a later Esprit with the KH system is another option but again....cost

[karluk29]

to swop the system, you can keep the disks and lines etc etc, its just the feed as such?

well after playing with mine it seems its a faulty wire, but where is the fault, inside the damn switch. if you push and winggle the pressure switch it works, cleaned all the connectors and plugs, but its still the same, how annoying

[Jonathan]

My 1st port of call would have to be an old V8 or GT3 with the K/H system in it.

You know that'll fit in without a problem.

If not then you can fit your own master cylinders but a degree of engineerig will need to go into it making the brackets etc.

I can't see any issue in not eeping the pipes etc - all you're swapping is the device that changes foot pressure into hydraulic pressure.

[htiek]

Following my earlier post I can now tell you that my ABS problem has been diagnosed as a faulty rear wheel sensor. A spare has been ordered up and I am just awaiting a date to get her booked in again. Annoyingly, the ABS has been working flawlessly since its visit, possibly fiddling with the wheel sensor has been enough to coax it back into (temporary) life, but I am not that happy about driving her until I know the brakes are OK.

While waiting, I thought I would just potter about in the garage tidying up some other bits and pieces. The PO had an alarm fitted (by monkeys) and it has not worked since I got the car. While repairing the bodged splices (one insulated with brown parcel tape!) and removing the alarm loom from under the front bonnet I was horrified to find a puddle of brake fluid under the master cylinder!

It appears to have eminated from the master cylinder cap as there are definite signs of leakage around the seal. After a thorough clean up of the spilt fluid (black paint has now gone from that area) I took the cap off to examine the seal. I can't see anything wrong with it, looks like new. I wiped down the faces and refitted the lid but I have to say I'm not convinced that the four clips are doing a fantastic job of holding it on. Am I correct in saying that the reservoir(s) are not under pressure?

Another possibility, if the garage took the lid off when the accumulator was charged would the level appear to be low? I wonder if they have added fluid and now its too full.

Any or all ideas/suggestions gratefully received!

Cheers,

Keith

[Jonathan]

That one is as far as I am concerned under pressure - the lid says to discharge the accumulator (pumping the brakes with the battery diconnected) before removing it....never tried it but I don't really want to see what happens if you do - can't be a huge amount of pressure (or it'd blow the lid off) but it must be enough to make it leap out if the cover was not on.

Refill proceedure is stated in the manual, it's possible the levels were not correct - both have to be to the correct marker before replacing everything and switching back on.

If it's any re-assurance mine has a little pool of fluid under it as well I keep having to mop up, not much but enough to have to clean up.

Having said that, mine is faulty - when I finally get this rad back on I can check it out, my mission to do a Wiki for this system.

[gertjan]

Well from now on I also can become a member of the brake problemclub.

The freaky light starts flashing as soon as i turn the ignition switch or touch the brakepedal.

I dont think it

[Dasar7]

I haven't solved mine yet either, but I'm starting to think its the movement in the actual brake pedal? I can get the ABS light to flash, while not moving (so not wheel sensors) & also with iginition on but without the engine running. Does this make any sense to the gurus out there?

All ideas/clues/guesses greatly appreciated.

Cheers

David

[DanR]

Is your brake light staying on? If so adjust the switch.

[fflyingdog]

I agree with Dan ,check brake light switch on your brake pedal isnt out of alignment,just a note but you havnt fitted LED rear brake/tail lights have you ?

Cheers

Nick S4s

[Dasar7]

Dan & Nick

No, brake light isn't staying on - I used to have this problem, but adjusted the switch under the pedal to stop this, & no, I haven't fitted LED lights either.

What I do know is though, if I 'fiddle/adjust' with the switch under the brake pedal to see if that makes any difference, then go for a drive, it seems to take a little while before the ABS warning light starts flashing.....as if the ECU is working out a new fault or something.

Think I am just cluthing at straws.

Cheers

David

[fflyingdog]

Hi David

If you turn the ignition on (but with engine not running) and then hit the brake pedal do you get an abs light (flashing)? Also try just sitting stationary with ignition on(again no eng running) and hit the brake pedal ,how many times do you have to hit the pedal before you hear the pump running??it should be around 3-4 ish,If it doesnt cut in or cuts in before you have hit the pedal at least 3-4 times then it sounds like your pressure switch is to blame,i had the same problem as yours and i am afraid to say it was the pressure switch.I know not all abs snags are down to the pressure switch but in my experience 9 out of 10 bloody are,they are a pain in the arse and so expensive you would think they were knicked from the space shuttle.

Cheers

Nick S4s

[gertjan]

Are you saying, that all the trouble can also be caused by the brakepedal switch?

Mine doesen

[fflyingdog]

Are you saying, that all the trouble can also be caused by the brakepedal switch?

Mine doesen

[gertjan]

Nick,you were right.

The brake pedal switch was disconnected from it

[Paul93Lotus]

I have recently purchased a 1991 GM Buick Regal oem manual. It has an entire section on the powermaster 3, and I also have a technician repair guide with flow charts and troubleshooting aids for the PM3. Once I get all this stuff together I am going to start scanning. Is it possible to have it hosted on the board somewhere. From just the technician guide there is info that we don't have in the Lotus version...one is a chart that has problems that will cause a blinking abs, solid abs, and the red brake light on. Many of the flow chart diagnostics (though for use with a Tech 1) can help someone trying to fix a problem.

I just want to be sure there is somewhere where it will be easily accessible for all to take advantage of...

[Artie]

I'm sure Bibs would set up a Pinned section for this, you may pm him Paul.

Artie

PS, got the deflector back from paint! Can't wait to get a day above 0 to try it out now!

[Dasar7]

Nick

Yes, I can turn igniton on without engine running & press pedal a few times & get abs light to flash. (BTW pump comes on either every 3 times, but more often than not every 2 times). I think you're right, its most likely the pressure switch. Brakes still seem to perfom fine though, just that the light always comes on.

Don't believe I'm losing any brake performance, it's just that I don't like these sort of problems especially when it comes to brakes.

Cheers

David

[Jonathan]

Is it possible to have it hosted on the board somewhere. From just the technician guide there is info that we don't have in the Lotus version...one is a chart that has problems that will cause a blinking abs, solid abs, and the red brake light on. Many of the flow chart diagnostics (though for use with a Tech 1) can help someone trying to fix a problem.

I just want to be sure there is somewhere where it will be easily accessible for all to take advantage of...

Good stuff - hoping to tackle mine this week as the Rad is back on and just needs finishing touches - the ABS unit is out at the moment (access to bolts) so it has to be done - love to see the guide though.

Suggest getting Kato to host it as an article on LEW and then linking it to here on the Wiki ?

Love to get a guide done if I have much joy with it, a serious nut could be on the verge of being cracked !