Abs Woes

[lemoncurd]

Sorry to go off on a rant here, but I need to get it off my chest...

I was hoping to get to LeMans in the Esprit this weekend, but it looks like we will now be going down in my Dad's car instead as I am still fighting to solve my current ABS problems...

I have posted about the symptoms before, but here is a brief summary: It went into the garage a few weeks ago after suffering from general braking problems. After turning the car on the ABS warning light immediately comes on solid following the first application of the brakes. The pump kicks in on every press and the low fluid pressure light also comes on briefly. The initial diagnosis was that the master cylinder needed replacing.

Given that these Delco parts are so hard to get hold of, I initially phoned round a bunch of people and looking into the possiblilty of replacing the whole setup with either the SE brakes, later V8 ABS, or a dual master cylinder setup. While doing this PNM mentioned that they had a master cylinder from an S4 that they would be willing to sell to me, so I decided to go down the repair route rather that attempt a complete replacement.

We have now replaced the master cylinder and reset the computer (once we got hold of the correct Tech 1 cartridge). This has fixed a large number of the errors, but there is still a low precharge error being flagged and the ABS light is still coming on. The garage now thinks that this is either the Accumlator or the Pressure Switch, but cannot tell which is the problem and is recommending replacing both...

As PUK have some of the accumulators, Marcus is now sending me one so hopefully that will fix the problem, otherwise I am back to trying to track down a replacement pressure switch or replacing the whole thing

Ben

[fflyingdog]

Ben

Pound to a Dollar its the pressure switch not the accumulator,and sorry to say this but in my opinion it was always the pressure switch giving you grief.

Good luck

Nick S4s

[Kato]

Not sure if this is of any help, taken from here: http://www.lotusespritworld.com/ERunning/partprices.html

BRAKE ACCUMULATOR FOR '91 ESPRIT

Following a helpful clue on this board, I found that the brake accumulator is the same part that is used by Jaguar. On the Jaguar board, I found that the same part is used in GM cards - GM Part Number 25528382.

The cost from www.gmpartsdirect.com is $86 plus shipping and handling. This sure beats $$$? from Lotus, or $400 from a Jag dealer or $200 from a mail order Jag parts supplier. These things are made with different pressure loads. I have no idea what this one is, but it seems to work just fine. 10 minute job to replace.

I ordered the part that lotusesprit16 suggested from GMPartsDirect.com. It was delivered in just 3 days (on a Saturday) via Airborne Express. Although the part is indeed an AC/Delco, it is not identical to the original accumulator in my Esprit. Differences are 210bar for the new part versus 207bar for the original. The other difference is that the original is torqued by means of a 17mm socket while the new one uses a hex head (allen-type) driver.

Installation was a 5-10 minute job. Although I did depressurize the system prior to removing the old accumulator, some pressure remained in the system and that sprayed a small amount of brake fluid. Luckily I expected this and had surrounded the area with absorbent towels. Installing the new part was just as easy except that there was limited access to torque the accumulator because of the different hex head.

I have take it out for a couple of test drives and everything seems back to normal. The ABS pump now cycles every 6-7 presses of the brake pedal rather than the 2 presses with the old, tired accumulator.

I suspect that the higher (210 bar) pressure rating is not a problem since this appears to be a maximum rating and not the operational value.

[98GT3]

As you have a GT3, it depends on which ABS system you have. Later GT3's have the Kelsey Hayes 430 system coupled with the bembo calipers - this system does not have a separate pressure switch! I spoke to Lotus technical about it and they do not have a fix for it yet, but are working on it. The guy spoke of making a repair to the system by replacing a pressure regulator on the accumulator/pump assembly - note this is a regulator and not a switch - as yet no fix is available by my understanding.

Phil

98GT3

[lemoncurd]

As you have a GT3, it depends on which ABS system you have.

It is the older Delco Morraine system...

Pound to a Dollar its the pressure switch not the accumulator,and sorry to say this but in my opinion it was always the pressure switch giving you grief.

I suspect that there was probably something wrong with the master cylinder, so I am not to worried about having replaced that - WRT to the pressure switch, I hope you are not right! () but I think you might be - At the moment I am using ease to obtain as my decision criteria, hence the accumulator! I know on the Parts X-Reference there is mention of an alternative pressure switch: AC Delco part 18M873 that replaces GM Part 88927270 - has anyone fitted this part who can confirm it works?

Ben

[superdavelotus]

This might help, Douglas Valley have two S4s or at least they did a couple months back. Ring and see if they have the parts you need. Have you tried Malc Holmes?

[lemoncurd]

This might help, Douglas Valley have two S4s or at least they did a couple months back. Ring and see if they have the parts you need. Have you tried Malc Holmes?

Thanks for the reply,

Unfortunately Douglas Valley had already sold the ABS parts when I checked a couple of weeks back (looking for a master cylinder) . I think Malc has the ABS parts for the new Kelsey Hayes systems and the older SE non-ABS brakes, but non of the Delco parts.

[fflyingdog]

Ben

If you can source a switch in the US i can get and pay for it,i am in the states next week on a course so if you get all the details i will buy it and bring it back for you ,just get all details and we can sort payment out when you have the part .And of course it will cheaper than paying Sterling for it.

Cheers

Nick S4s

Edited June 12, 2007 by fflyingdog

[scott.ashdown@medley.co.uk]

Hi Ben,

I'd be really interested in knowing what complete replacement system options are available. I have exactly the same problem with getting hold of the presure switch (affordably) from x-ref parts. Come back to SJ and SWLC offering them at

[Jonathan]

I am having a similar problem where the system simply doesn't provide much power assist, although I am not getting any errors.

I've done buckets of research and I've drawn the conclusion it's the pressure switch.

One way to find out is to switch the car completely off and press the brake pedal umpteen times to depressise the system totally.

If in doubt do this for 5 mins (although it says 40 pedal presses)

Now switch the car back onto position 2 and the pump should run - count out how long it goes for.

Correct pressure shouled be achieved by 40 seconds - any significant amount either side of that means the pressure is not coming up to what is expected.

My pump stops at 20 seconds, but all the otehr diagnostics check out fine.

You can test the accumulator by letting the system fully pressurise (ie wait for the pup to stop) and then press the brakes in firmly.....count out again and see how long it takes until the pump kicks back in. This tests the pressure hold - it should be about a minute or more, if you count 60 secs its fine and the system is holding pressure (ie not the master cylinder or the accumulator).

[scott.ashdown@medley.co.uk]

Thanks J.

I timed the above procedure. It took 17 seconds before the pump stopped. Then after applying the brakes, it took 44 seconds before the pump came back on. Given this and in my opinion, less than I would want braking performance (similar to yourself) I am changing both accumulator and switch. I have checked wear around the discs and pads which are all fine, and bled the system, so I'm hoping better pressure will assist the brakes more.

AND I have, by chance, found a switch from a dealership who had one left in stock. I was going to ask about what they would recommend in the event there were no more switches to be had, but that got put on ice, at least for a year before this one gives up!

[fflyingdog]

Thanks J.

I timed the above procedure. It took 17 seconds before the pump stopped. Then after applying the brakes, it took 44 seconds before the pump came back on. Given this and in my opinion, less than I would want braking performance (similar to yourself) I am changing both accumulator and switch. I have checked wear around the discs and pads which are all fine, and bled the system, so I'm hoping better pressure will assist the brakes more.

AND I have, by chance, found a switch from a dealership who had one left in stock. I was going to ask about what they would recommend in the event there were no more switches to be had, but that got put on ice, at least for a year before this one gives up!

Hi

The switch you get from the dealer should have a grey moulding this indicates that it is a later one with revised pressure limiting parameters,the old one has a black moulding,if you fit the black one and still have problems(probaly a flashing abs light) you will need the later "grey" one ,sorry to sound like the angel of doom but at least you will have an idea in which to start.

Cheers

Nick S4s