New ABS switch delivered yesterday

[Richard123]

1 hour ago, ian29gte said:

Interesting, thanks.

I still reckon the Hydac would be a better bet long term if you're sticking with the Delco. I'm still undecided, all the time mine appears to be working. I don't really want to spend any money on the Delco, only to find something on it fails!

Did you get another daily-driver then, Richard?

Oh ya, we have 8 months of winter here, so I keep my winter car insured all year round, lol.

 

Although I must say that on these sunny days I feel a bit depressed knowing the ole Lotus is parked in the garage.  Seems so wrong.   

[Richard123]

Put the switch back together and surprisingly it seems to work.  I cycled it a few times in the garage and am now back on the road, albeit nervously!

 

I didn't do enough to the switch though, so I'm not ready to declare it fixed.  But at least I know I can take it apart and successfully reassemble it.

 

Oddly, I had the accumulator and switch off for 2 weeks and haven't bled the brake system yet.  Brakes feel normal and I'm getting 5-6 presses between pump cycles.  I was expecting to need a complete flush and was prepared for the pump to cycle every couple presses.  I am going to drive a bit before bleeding.  Perhaps driving will push the air into the brake lines?  Or maybe it stays in the accumulator?  I'm not yet confident this is a permanent fix.

 

Also, seeing how the pressure switch diaphragm "flips", I will press the brakes a few times after parking it for the winter so the diaphragm can flip back to its relaxed position.  That seems more logical than leaving it flexed all winter! 

 

(And I will still grab one of Ralf's switches if/when I get in touch with him.)  But I'm back on the road.

[PaulEspritGT3]

On 15/08/2016 at 16:46, Richard123 said:

Oddly, I had the accumulator and switch off for 2 weeks and haven't bled the brake system yet.  Brakes feel normal and I'm getting 5-6 presses between pump cycles.  I was expecting to need a complete flush and was prepared for the pump to cycle every couple presses.  I am going to drive a bit before bleeding.  Perhaps driving will push the air into the brake lines?  Or maybe it stays in the accumulator?  I'm not yet confident this is a permanent fix.

Hi Richard,

In case it helps....

When I first started playing around with the accumulator/pressure switch on the brake system I was also very concerned about needing to bleed the whole system, but this should never be neccessary. I suggest that you don't even attempt to do any bleeding.

There is no link between the fluid in the two parts of the reservoir.

The fluid that feeds the front brakes is only taken fron the from the front part of the reservoir and nothing you do with the accumulator/pressure switch affects this part, the fluid in the rear part of the reservoir is used to charge the accumulator and to feed the rear brakes.

The accumulator/pressure switch part of the system is self bleeding, whenever you de-pressurise / re-pressurise it it bleeds itself, air cannot get into the rear lines (unless you do try to bleed them!).

[Richard123]

10 minutes ago, PaulEspritGT3 said:

Hi Richard,

In case it helps....

When I first started playing around with the accumulator/pressure switch on the brake system I was also very concerned about needing to bleed the whole system, but this should never be neccessary. I suggest that you don't even attempt to do any bleeding.

There is no link between the fluid in the two parts of the reservoir.

The fluid that feeds the front brakes is only taken fron the from the front part of the reservoir and nothing you do with the accumulator/pressure switch affects this part, the fluid in the rear part of the reservoir is used to charge the accumulator and to feed the rear brakes.

The accumulator/pressure switch part of the system is self bleeding, whenever you de-pressurise / re-pressurise it it bleeds itself, air cannot get into the rear lines (unless you do try to bleed them!).

That definitely helps Paul.  Helps my nervous system that is!!  

I was wondering how I could possibly be getting more pedal presses between pump cycles with all that air being compressed in the lines.  Your explanation makes perfect sense and fits with my current experience.  

I'm only a few days in, but the pressure switch and complete braking system has been behaving.  The sun is shining, I'm driving an Esprit, and there is no need to bleed the brakes.  Life is good, innit?  (He says as he knocks on wood.)  

Thanks again. 

[Big_D]

 

Just FYI
I contacted Ralf in regards to his ABS switch for an Esprit. His response was:

On 30-Nov-16 8:05 PM, Ralf Burk wrote:

  Sorry, i do not sell them anymore !!!

[markw996]

I realise that this is quite a thread resurrection, but I wondered if the Hydac switch has been performing well for those that went down this route, and if in 2023 this is now the best solution for those wanting to keep their Delco ABS system as standard as possible?

I purchased a Lotus Marques dual switch kit back in 2015 and now my ABS is playing up again. I suspect one of the switches has failed so I've pulled it all apart with the aim of installing a pressure gauge to help diagnose the issue.

I'm now thinking that rather than install a gauge I could just install a Hydac switch and kill two birds with one stone?

Only issue is that the switch seems to have a 20 week delivery time from the 2 UK suppliers I have tried so far

Thanks,

Mark.

Edited January 16, 2023 by markw996

[ramjet]

@markw996 I would recommend getting in touch with Steve as well as I would think he would want to know what is going on as well. 

[markw996]

Okay so despite owning my Esprit since 2013 and fitting the Lotus Marques kit way back in 2015, I seem to have misunderstood how the system works. One switch controls the pump high and low pressure, and the other just controls the red brake warning light on the dash. I was previously under the impression that one switch turned on the pump and the other switch turned it off!

My Lotus Marques setup turns on the pump at around 2300 psi and off again at 2700 psi so I guess that saves me buying a Hydac switch.

As my pump runs every brake pedal press I'll be replacing the accumulator (again, last one was 2005) which should fix it 🤞

Edited January 27, 2023 by markw996

[ramjet]

Hi Mark. I would drop Steve an email and check with him because as far as I know there is a low pressure switch and a high pressure switch. There is not one switch which looks after both pressures as far as I am aware.

Steve has always answered any questions I have asked about the kit, so I am quite sure he will reply to an email from yourself.

Do you have a gauge that enables you to check what the pressures in the system are doing? That will indicate to you whether you have a switch issue or whether the accumulator is shot. I believe the life of an accumulator is ab out 10 years max, so if you have made it to now from 2005, you've done pretty well.

[markw996]

Sorry, 2005 was a typo, it was meant to be 2015 (so still 8 years ago and probably due for replacement by now).

I emailed Steve last night and he replied straight away telling me that "The low pressure switch function is purely to monitor the system pressure and illuminate the ABS warning light on the dash" so the larger switch must control the pump on and off pressures. This explains why I was seeing no change on my gauge when adjusting the low pressure switch, and hence why I assumed it was faulty.

I have already fitted a gauge so I can see exactly what is going on, and the pressures are pump on at 2275psi and off at 2700psi.

I'm going to replace the accumulator and will try to lower the pressures to set the pump on at 1800psi and off at 2300psi.

I've emailed Steve again to check how to adjust the switch as it only seems to have a single setting screw on the back, so maybe it has a fixed 400psi range or maybe only one of the setpoints (upper or lower) is adjustable.

[ramjet]

Hmm. That's interesting. I have a different understanding of it. I'll catch up with Steve on Monday to clarify it for myself as well.

[markw996]

Just to update, I was correct that the Lotus Marques high pressure switch is a differential switch in that it has a 400psi band between turning the pump on and turning it off. It has just one adjustment allen key screw. I've set it so that it now turns the pump on at 1900psi and off at 2300psi. I've also set the low pressure switch to turn the red tell tale light on when the pressure drops to 1500psi.

I had read somewhere that a Mercedes accumulator (Bosch 0265202070) was a direct replacement in the Lotus Esprit... but this is NOT the case. It does not have the clearance around the headlight motor and so will not screw on far enough. It felt tight but I ended up with brake fluid all over the place before I realised it was tight against the headlamp motor arm and not against the O ring. I leave this here in case anyone else makes the mistake of believing everything they read on the internet! 😒

I've sent my Delco 25528382 (which I actually fitted in 2013 not 2015) to a place on eBay that offers a testing, re-gassing, and leak testing service for them to check and re-gas to 1200psi for me. I'll update what the brakes feel like when it comes back.

[Clarky5150]

On 30/01/2023 at 09:06, markw996 said:

Just to update, I was correct that the Lotus Marques high pressure switch is a differential switch in that it has a 400psi band between turning the pump on and turning it off. It has just one adjustment allen key screw. I've set it so that it now turns the pump on at 1900psi and off at 2300psi. I've also set the low pressure switch to turn the red tell tale light on when the pressure drops to 1500psi.

I had read somewhere that a Mercedes accumulator (Bosch 0265202070) was a direct replacement in the Lotus Esprit... but this is NOT the case. It does not have the clearance around the headlight motor and so will not screw on far enough. It felt tight but I ended up with brake fluid all over the place before I realised it was tight against the headlamp motor arm and not against the O ring. I leave this here in case anyone else makes the mistake of believing everything they read on the internet! 😒

I've sent my Delco 25528382 (which I actually fitted in 2013 not 2015) to a place on eBay that offers a testing, re-gassing, and leak testing service for them to check and re-gas to 1200psi for me. I'll update what the brakes feel like when it comes back.

Any update on the accumulator repair please?

[markw996]

On 18/08/2023 at 10:35, Clarky5150 said:

Any update on the accumulator repair please?

Sorry I didn't see the message notification.

I sent the accumulator off and it was reading near perfect, I still had the guy top it up to 1200psi though.

When I put it back on the system was just as bad, pump running every pedal press and just a gentle press seemed to use most of the pressure with the gauge dropping right back. My fault is probably within the master cylinder but I don't know where the pressure is going.

I've given up with the ABS now and am half way through fitting one of Ians excellent ABS delete kits. It really was my last resort but the price of a used Delco master cylinder (with the associated risk of it potentially being on its last legs or not actually resolving my issues), was the final nail in the coffin.

Regards,
Mark.

 

[Gjk]

Congratulations on seeing the light and fitting a ABS deletion kit. The difference between servo assisted and the ABS system is incomparable.
Yes, you have lost the fact that the ASB system would not allow you to lock the brakes up but, it was so basic that it struggled to bring the car to a stop if needed! (personal experience).

[mr.oogieboogie]

Well I managed to get a switch from ralf. Great guy excellent service and communication. Will fit this after Christmas.

Price was £214 plus customs clearance of £61.09.

All the best