Brakes 1992 SE AntiLock (ABS) Failure Really confused now.

[MikieP]

Hi all.

Having read through many of the failing brakes threads I am not sure what to do next.

Receiving the car back from the last shop, I was told that the ABS was not working and the Anti-Lock Tell Tale would be blinking... OK. Drove that way for about a year with no apparent issues. Got in the car last week and the Handbrake/Brake light was on. Fiddled with the Handbrake lever and did nothing to put it out. Assumed the handbrake switch had failed or not returned to its off position. Then once om the road for about 15 minutes, the Anti-Lock Tell Tale now was staying on but I still seemed to normal brakes during about an hour ride, mostly open road, and then I didn't. Pedal still high off the floor but like I was sliding on ice as far as stopping went. Being a complete idiot I drove the car home with several stops on the side of the road en route. Surprisingly, the braking would return to normal for a period of time and after 30-40 minutes it would again lose what I presume is the power assist and then I would pull over again for ten or so minutes and it would return to normal, yet again.

Checked both the clutch reservoir (round plastic cap which was almost empty - 1/4") so went and bought 3 cans of DOT 4 Brake fluid thinking I would find the larger black plastic brake reservoir low as well. After doing the 40 pumps, I removed the top and found it so full if I had parked with nose down it would have spilled over the front rim. Starting the car I could hear the pump run for about 3-4 seconds and all was normal. Took it for another drive and still failed after about 40 minute cruise. No apparent leaks on the floor (I have cardboard underneath so they would show up) nor in the front compartment.

Pedal has always remained high though when braking failed, I would hear grinding noises from the front brakes. Go figure. There are no shops that will work on the car withing 150 miles. I have never gotten the lap top to work with the ECU.

Next step, please.

 

Mikie

[Jacques]

Hi Mikie,

I would first look for the obvious.

- Look at fluid level now.

- Look for spills, that may run into a cavity and collect there, if you have no spills on the floor on the cardboard.

- you could take off the abs system and connect hoses as a normal old school braking system.

- I believe it was in an old episode of "wheeler dealers" (watch it on youtube), that they took the old type abs unit to a specialist, who took it apart and renovated it to be fully functioning again. Some electromagnetic valves or alike was stuck. Worked perfectly afterwards and was not expensive to repair.

- brakediscs. How are they? thin, scorched, blue or?

- brakepads. How are they? Worn, with glass like surface or ?

- brake calipers. Can the pistons move freely?

- Do you have the old small Toyota brakes? Or something bigger?

- Take a look at the vacuum system for the brakes. Does it have sufficient brake vacuum for brake assistance? Or do you have to really step on the brake pedal, to have any brakes at all?

- Does your brakes drag and get really hot after having been driving for a while? What are the temperatures of your rims in that situation?

- did you take a look at the handbrake switch itself? If you have the 1993 onwards design, the microswitch for the parking brake sits next to the rod or link, going gron the parking brake lever, to the multiplier (that holds both cables). This is all situated in the drivers side, NeXT to the lower part of the seat, under a flap in the carpet for easy access. You may want to take out the drivers seat to gain better access. Eventually see page 33,05a in 1993 onwards parts manual. I think you have that already, otherwise it can be freely downloaded from this forum.

- Laptop. Do you have the correct cable to connect between the laptop and the aldl connector(-s) on the car?

- Do you have "Freescan"? Can be downloaded for free.

- Which Windows or other system are you using on your laptop?

- On my laptop, I have to go into settings and direct the port to COM 2 (or COM 1). Then do the same in Freescan. Press start in Freescan, and it should Work. Most Windows based pc's won't direct the port automatically.

Cheers,

Jacques.

[MikieP]

Hi Jacques!

Thank you for your interest and guidance, again!

Fluid is probably too full - up to the rim of the reservoir. That was my first hope for fixing the loss of braking but was disappointed. I have perfect braking, for a while. Then they just go away and need a horse to push on them to stop the car. Stop, give the car a breather of say 5 minutes in off mode, then start her up and they are fine, yet again, for a while, and then repeat the loss, stop, and then go again.

Have the usb version of the cable but never could get it to recognize any port... Laptop versions are XP, 2000, and 7. None seem to work. Both Freescan and EspritMon. Pump runs when car starts up, but 30-40 minutes later, all assist is gone. Turn car off, wait 5 minutes and it is all well again.

 

Mikie

 

[Vulcan Grey]

You need to read the codes off the ABS ECU with the free Espritmon software and an ALDL cable connected to the ABS ECU plug under the dash (not the main engine ECU ALDL plug).

 

Enlist the help of a more tech savvy (Windows PC) friend.  Windows XP is easiest.  

Sounds like your accumulator or pump system has a leak, though it could be the master cylinder solenoids, or some other error... Can't really say unless you get those codes.

 

 

[Jacques]

Sounds like Travis says, you'll need to link up that pc to the abs unit and make a  readout.

Anyway, I would make sure, that there is not too much fluid in the container. It needs Space to Work.

Generally speaking, it sounds to me, as if the brakes are dragging after a while, and after a cool off period, they can do for a while Again and so on.

So, while you find a friend to assist you linking up the laptop (quite easy if you remember to assign the correct port to the cable like I tried to describe), you could take a drive, and then measure the brakecaliper, brake disc and hub and Wheel temperature on all four Wheels. I use a super cheap infrared pistol like type with a small display, from a general store with tools and Building materials. Cost something like 9 usd. Or I use a more precise type connected to my Fluke 179. But that is not needed in this case.

Another thing you could do while setting up the test, is to Jack it up at home, turn all four Wheels byhand and feel if there is any resistance. Then take a drive, getting to the point of very bad brakes as you describe, and exactly then, Jack it up Again and turn the Wheels. Any drag would be easily felt. Remember gloves

My point is, that if either a caliper, or calipers as in plural, or the abs unit making up drag, will be easily detected. Let us hear what you find. Should be easy to do right now

Could also be a leak in the vacuum assist connected to the abs. That, I suppose, will be detected by a read out from the abs ecu.

Speaking of abs ecu codes, there is probably someone off here, that could interpretate them if need be.

Cheers,

Jacques.

[swindon_alan]

Addendum

http://www.wcengineering.com/articles/absbrakes.html

Lotus Esprit ABS

In my opinion, the ABS on the 1991-1995 S4 Esprit is one of the worst systems that ever been installed on an automobile. I challenge anyone to find a single engineer that will admit without duress that they had any involvement in the design, development, or application of the system. If you enjoy a variable pedal height, inconsistent pedal pressure to caliper pressure ratio, unnecessary electrical load, noisy accumulator pump (carrying a spare liter of brake fluid), and not to mention excessive weight, then this is the system for you. If not, remove it and replace it with the brackets and master cylinder from a 1989-1990 Esprit.

I find it interesting that the system was used only on the federalized Esprit and not the European cars. I have no evidence, but I suspect that there may have been pressure from the US to add ABS (and the crappy airbag) to the cars to help comply with the safety waiver obtained to import the Esprit. I say this because I have a great respect for all the engineering and design skills at Lotus and I would be very disappointed to find out that it was actually their choice to include such a P.O.S. system to an otherwise excellent car.

As for the later Kelsey-Hayes 4-channel system, it is a great improvement. If you must have an ABS system, this is the one. However, for track use I wouldn't mind being able to shut it off.

[MikieP]

WOW! Lots of replies. Thank you all!!!

Checked wheel temps and none were hot to touch at all, unlike when the handbrake caliper did not release one time. Am going to remove some of the fluid in the reservoir to the correct level, but doubt that could be the cause as it has been over full for many months without issue. Bought an accumulator from JAE just in case it can be found bad using the pressure gauge method that a friend thinks he has in his shop. Otherwise not really sure where to go next without getting the laptop(s) to work even though have tried using many com ports and usb ports they still remain unconnected. Replacement using older technology may be the ultimate answer but certainly no one anywhere near has been located to even touch the car for even oil changes since my last shop closed their doors. Stopping the car for a mere five minutes brought them back, for a while and that seems really weird.

 

Mikie

 

[MikieP]

WTF! Went out to garage and checked all fuses in the ABS box area and all were good and in their sockets. Did find two unplugged wires but left them alone. Plugged em back in and started car. NO ABS Blinking, NO ABS on solid and no Brake light. Going for a ride after dinner. It can't be that can it? WTF!@!!! Will let you all know what the results are later tonight if I do not hit a tree. lol

Mikie

 

[MikieP]

22 Miles, 18 brake pushes and NO LIGHTS, Plenty of braking. FUSES not making contact? Unbelievable! Will know more tomorrow if it does not rain here as I am gonna drive some more on the emptier roads around here to get a larger test of the system. I am starting to think I am one lucky bug. Funny thing though is the Anti-Lock was blinking once back from shop and was told they changed DOT 5 back to DOT 4 in the system and that the ABS would no longer work and the light would be blinking, which it has for many months with no apparent ill affect until the BRAKE lite came on last week. Cheers for now! Will remove some of the excess DOT 4 tomorrow before the drive.

Mikie

[sailorbob]

Which were the two unplugged wires?

[Chillidoggy]

Not wishing to hijack Mikie's thread, but I'm still very interested in ditching the Delco system. Spares are no longer available for the m/cyl, and at some point we're gonna need them. The main thing that concerns me is dealing with the electronics interaction between the brake system and the ECU, particularly the ABS warning lights.

Maybe a separate thread with all the necessary Delco-ditching info would be a good idea? 

[swindon_alan]

Yep, happy to set that up in the Esprit cross references section and copy the relevant posts over @ian29gte. I can also have a look at a mod to the interface as well to fool the ECM. That's if nobody has done that yet, will have a look.

Posts split out to:

 

[MikieP]

New news. Went for a ride today. All lights off until about 30 minutes in. Both came on while going around 25 mph, but did not drive until failure. Just pulled over and parked for about two minutes. Restarted and both lights off. Drove another 10 minutes and they both came on again but still had brakes. Rested car again for about an hour and tried again. This time the Anti Lock light was now blinking but Brake light remained off and stayed off for another 25 minute ride. The exact same as it did when retrieved from the last shop months ago. Thought I had found the problem - corroded fuses???? Nope. Shoot it. lol.

Mikie

[Barrykearley]

You need to plug in freescan/espritmon and find out what error codes are listed on the abs

[Bibs]

Espritmon. Freescan doesn't work on the ABS.

[MikieP]

Thank you! I will continue to try and get one of the three laptops (XP) to work with EspritMon. Seems to be the sole method to diagnose. Might even give John Welch a call for a transplant although getting it there will be an issue if he even will accept the project. lol.

Wish others' symptoms had been posted in comparison to mine so I might have better insight on where to look. I get the message about the system being an ugly part of the car. lol

Mikie

[s4simon]

My abs problem over the last twelve months was finally resolved today. Initially it was an occasional flashing abs maybe once every couple of months, then once a month, then every second trip after half a dozen of brake applications. Came up as a code 62 - low accumulator. Using espritmon and a laptop using win 7 + Aldl cable with a USB interface. Replaced the abs switch, which then caused the same 62 problem but now the flashing light came on after only 1 brake application on every drive. Replaced the accumulator today (previously replaced back in 2003) and all my abs issues have disappeared. Replacement switch was purchased from Steve at lotus marques australia, an accumulator from Steve at sj sportcars UK.

[MikieP]

Simon,

 

THANK YOU! Your symptoms sound quite similar though not exactly the same. I have yet to get EspritMon to work with my hardware as previously stated, and now I am beginning to think that what it might discover could be erroneous after looking at the software et al. I received my 3 lb accumulator from JAE ($410) yesterday and may just proceed with its replacement if I can find someone to do the task. What is different is that my lights do not come on at all now until after a drive and go off after a rest period of 5 minutes. But sometimes starting the car up fresh does blink the ABS light only until I drive it enough to bring on the Brake Light and then some time later the brakes fail to work. Does not sound as it being any of the sensors, but rather pressure / hydraulic anomalies... Did your BRAKE - HAND BRAKE light ever come on? Or your brakes simply no longer work or just the ABS light indicating a problem, please? That is the only thing that confuses me at this point as it does not seem to be pressure related in the schematics.

[s4simon]

Looks like mine was a slow reduction in accumulator pressure over the years. Gradually got worse over probably a 2 year period. And no my brake error light never came on, and brakes have never failed, although I don't think I have a brake fail light on the S4, just the abs light. I was a little worried with replacing the accumulator today as I'm not an auto guy, but all went well. Depressurise system, unscrew old accumulator, prep the new accumulator by lubing up the new o ring, screwing on new accumulator. Half pressurise the system, check for leaks, then fully pressurise the system, test drive.

[MikieP]

Last post gone missing for some reason... Go figure. So again, thank you for your symptoms post, Simon. Some new insights for me. Anyways, two hour ride and no lights at all. Damn. Will take a longer ride next sunny day. Still working on getting the USB - serial cable to work.

 

Mikie

[s4simon]

I had to configure/ set the USB port on espritmon, otherwise it just doesn't talk to the ecu and sits there dumb going around in circles.

[MikieP]

HI Simon,

 

Looking for any guidance on that one, too. Perhaps I am trying to hook to wrong pins as well?

 

Mikie

[s4simon]

I have the same problem everytime i use the software, which is probably once every 5 years. You have plug into a usb port and also find out what com port that usb is in. Look at the properties of the usb ports. Once you know which one you've plugged into then go to the espritmon dorectory and goto the cfg directory and open up the lotus cfg file. It will then state a com port it will use. This must be the same as what your plugged into. If it isnt, edit the file and change the number and then save the cfg file. Now restart the program and it should work. I read the instruction manual to figure this out. See how you go.

[MikieP]

 

roger that Simon. Did that but maybe I am not using the correct pins then in the front connector then?

[s4simon]

Front connector meaning the front connector in the car or something else.  I know that if I plug my cable into the front connector in the cabin it doesn't seem to work - goes all stupid.  But if I plug into the connector in the engine bay all is fine.  I have taken a pic of my ALDL cable connector as well for info. Black to A, Red to F, and Yellow to G.