Converting to Kelsey Hayes 430 - Any helpful advice?

[Paul93Lotus]

I have acquired the following:

 

Lotus V8 Master Cylinder and Booster with bracket and push rod

Kelsey Hayes 430 (Lotus) ABS Unit with pump and mounting bracket

Electrical Harness connector to ABS Unit

Brake lines that connect Master Cylinder to ABS Unit and to bulkhead connector

Pedal Box from V8 (but not sure if needed)

 

This will be retrofitted into a US Spec S4s with Brembo brakes.  I have been checking the wiring diagrams of both the stock Delco Morraine set up and the V8 Brake system.  Wiring to the abs wheel sensors looks like a standard switch...same part numbers and wire colors..Power feeds and grounds look the same for the most part, I only have a couple wires to figure out, and the wires that go to the Engine ECM are only V8 specific and can be ignored.

 

I have looked into buying some of the V8 brake lines and they are the most part obsolete - never thought there would be much demand for these to be sold out...but who knows if the parts were just sold off. I figure I can always bend my own lines that are needed - probably cheaper any way.

 

My main concerns are:

 

The GT3 has a vacuum pump with this set up...so is it safe to assume the 2.2L doesn't generate enough vacuum on it own?  I was contemplating buying a new UL28 Hella brake vacuum pump for approximately $135 US, as well as buying a used vacuum reservoir from an Audi or VW, and of course a vacuum switch to turn on and off the pump which can be sourced aftermarket.

 

The front brake lines I think I could connect to by making some custom lines to the existing in situ front lines - no need to replicate the V8 lines up front?

 

Since the rear line is a single line with a proportioner, I am assuming I will have to run two separate lines if I want to retain ABS, and remove the proportioner, and then connect to the existing lines at that point?

 

Anything else that I may have missed?

 

I know I could probably just hook up the master and booster with a vacuum supplemental pump and call it a day, but prefer ABS...especially since this would be an upgrade to a 4 wheel version.

 

 

 

 

 

 

[glynherron]

A couple of years ago I gathered together all on your parts list too with the intention of the same conversion. Unfortunately due to lack of time I've not got anyfurther so I will be keen to follow this!

I know in the past that this has been done previously. It would be fantastic if you could document this as many owners may consider this. It may also give me the incentive to rebuild the engine and get her on the road again. ..

Thanks

Glyn

[glynherron]

Oh and I believe the pedal box is necessary as the centres of the old and new master cylinders are different? ?????.......

[Günter]

on most production-cars the pedal box matches the booster mounting bracket ..so simple it is Glyn @Paul: Anyway, as the late GT3 4 pot was also offered with the V8 ABS ..simply download the S4series workshop-book (wich includes the V8 partslist and 4pot) and go like that. the V8 ABS is with 4 individual sensors, and if you count the number of outlets on the pump-block you will see that it uses 4 channels (hydraulic) too ..as far as I can recall. So is an ordinary 4/4 system. The Vacuum is (for the booster) bypassed directly from the plenum on top (on the frontside) ..and there is a small (black) vaccum line too, for additionals as the interiour controls and water recirculation is actuated via vacuum.

[Paul93Lotus]

Gunter...I do have the S4 manual and have been referencing that from the parts lists...and the electrical wiring diagrams.

 

I am curious if anyone knows about the vacuum requrements on the 4 cylinder as far as how much vacuum does it produce...is the stroke of the engine that low that it cannot support a brake vacuum booster?  Does the GT3 have a vacuum line that runs to just a dedicated vacuum pump and that is all?  Or is there a line that pulls vacuum from the plenum and the vacuum pump?  There are two versions of the Hella pump I was considering...the UL30 pump is for electric/hybrids where there is no vacuum produced by an engine so they have a dedicated pump...but of course they are $100 USD more than the UL28 pump I mentioned above.

[Günter]

the LEW documentation for model-history only refers to the term 'vacuum pump' for the late GT3 cars ..but I would also like to see those later 4 pots too

-as we have a S4s in our group where the owner is interested into get rid of this old 'hydraulicpressure pre-actuated' powermaster brake system and convert to the later ABS-version.

 

on the point with vacuum supply:

the V8 does run most of its time with negative pressure in the plenum ..as under 'cruise mode' and on idle you can see that the turbos really not spin that fast until the rpm on the engine is 2500 or more. The MAP sensor sees most time only 30-100kPa and the plenum is for its own a good reserviour. So the engine is not in the *boost* situation that often in urban conditions.

 

Not sure how often the 4pot runs in this condition, as I think the generall boost pressure is set on a little higher level -so the increase in pressure starts earlier?

The position of the 4pot throttle bodys in relation the the inlet valves there on those engines, compared to the V8 plenum with only those twin ports far of from the inlet ports, this is an other notable difference for the pressure characteristics in comparision V8 to 4pot.  All those reasons seem to indicate that the 4pot can not generate (and hold) enough vacuum inbetween the time it would be required -therefore it needs to assist with an supporting vacuum pump as soon as you use an vacuum-assisted brake booster (instead of the pre-charged hydraulic one). If you work with one way valves it should be possible to use such pump in parallel

[Paul93Lotus]

Well I've studied the wiring for the conversion and all the relevant diagrams between both cars.  Mind you this is for the EBC430 and not the 410 that is on the 1997 V8 (there are some minor differences in the wiring between the two).

 

So far:

 

All abs sensor wires are a straight swap - colors are fortunately the same. There are 8 total wires, 2 for each sensor.

 

There are 4 "feedback" wires from the new ABS ubut that are not used.  These wires feed the engine ECU to limit boost on the V8 - no such thing on the SE,S4, or S4s. So those are left unconnected/removed from the ABS unit plug.

 

The Green-Purple wire "GP" connects straight up. Matching to color on the Delco unit. That read the stop lamp switch at the brake pedal.  The Purple wire that also runs from the Delco unit to the stop lamp switch is disconnected and not used.

 

The Orange wire "O" from the EBC430 is the diagnostic feed wire.  That connects to the orange wire on the Delco Unit.  The Orange-Pink wire "OK" from the Delco Unit is not used on the EBC430 and is left unused - it is used for "mode" switching...where as the O wire is the serial data line.

 

The Green Wire "G" from the EBC430 connects to a 10 amp fused power source.  This may be connected to the Delco 10 amp power wire Purple Orange "PO". On the V8/GT3, this appears to be an ignition switched power source (10 amp).  I have to verify if the Purple Orange wire is switched...not sure if that can be a constant power source.

 

The Black Pink wire "BK" from the EBC430 connects to BLG Wire on Delco unit (the diode is not present on V8 that is present on Delco, but it appears to be present to stop back feeding  from Delco Front Solenoid Relay. Alternative is to cut the wire before  the diode. I believe the EBC430 only provides a ground from which to light the ABS light, so this may not be a real issue to go hunting for a wire to cut. Theoretically all the Delco replays will be gone or disconnected from power, so the diode can probably be left in place and not be worried about.

 

The two Brown "N" wires on the EBC430 are direct power feeds to the +VE post.  There are no fuses on these for the EBC430, which is unusual.  These could possibly be connected to the two 30A fuses from the delco unit via the Delco Purple "P" wire that feeds ABS Pump relay and Purple "P" wire that feeds front solenoid relay on the Delco unit.  The only possibility is that the wires may pull more than 30A?  I would not think so, but per the Kelsey hayes book, the brown wires are large diameter current wires, so I will have to verify wire gauge so the power wires are adequate to feed the EBC 430 ABS pump and solenoids.

 

The grounds Black "B" wires (3 total - 1 bracket and two to -VE post)  will just connect to the Delco Black "B" wires...a ground wire from the bracket to the B wires may need to be added to assure ground of the bracket.

 

 

 

. 

[Günter]

as I have not compared the wirings (for now.) -all I can say is:

that the ABS on the older 4 pot cars is 'read' for diagnose via the same old style 10pin (Opel/GM) ALDL plug as the ECM  -right !?

 

..that's why you have to send a *change mode* signal if you use freescan to work there (remember the work Erik has done for his different type of freescan software, with tose software/mode extensions ..and as I asked him how to diagnose this Opel-ABS system on the V8 cars -who have 10pin-ALDL for ABS and the 16pin obd-plug for the engine)

 

Not sure how that interacts with your finds there on the wiring -I have never managed to read my own ABS system via the 10pin ALDL, but have verified that my DIY interface works with Eriks software on the ECM of 4 pot cars

[sanj]

The V8 ABS ECM is accessed via the 16-pin OBD-II port, not the 10-pin. The 10-pin ALDL is used for the SIR (airbag) for sure, and I believe the alarm.
 

The ECM mode switching wire on the 4-cylinder ABS ECM isn't needed for any diagnostics.

[Günter]

ahh see -big fault of mine ..I'm a little *confused* with lots of stuff to sort out the last days (in the head & in the life) 

 

-you're right   ..not ABS is on this  -the Airbag was on the GM-type 10pin ALDL ..so I mixed this up with 4pot system !

 

 

anyway ..there was something with needs to send a 'switch mode' signal in the discussions with Erik on the 4pot interface thing -maybe this is not related to the old wirings in his car at all

[sanj]

The mode change is sent as a software command via the data wire, Erik could probably explain how.

[Günter]

as far as I can recognise it

 

-or lets say as I think it is meant  ...

it was needed as all systems run on the same port, and as it is an 'pre CAN' communication, so you have to stop communication and restart it on the other components 'one after the other' for diagnosis.

[davevr6car]

I had a look at doing the same to my S4s, because the brakes were so crap. I then test drove a V8 with the later type ABS and I didn't think much of the brakes for such a high powered car. My work Ford Fucus car has better brakes. I stripped my entire brake system outand replaced it with: AP 4 pot calipers up front with larger S350 drilled discs 4 pot calipers mounted on s300 brackets with s350 rear drilled discs Kept the brembo calepers for the handbrake. I using a Nissan Patrol servo and master brake cylinder mounted on a custom made bracket which is connected to the original pedal box. I have remove the air con pump and in its place I'm using the earlier esprits vacumn pump. I made up a bracket for the pump to fit where the air con pump used to be and using the air con belt tensioner to tension the new vacumn pump belt. This supplies a constant vacumn to a audi A6 vacumn resevoir in the front comparment. I have a turbo bleed valve fitted with vacumn gauge before the resevoir and one way valves. This is then connected to the Nissan Patrol servo. What this mens is that I can adjust the amount of vacumn going to the servo which mens I can adjust the amount of servo assist from inside the car. The brakes are unbelievable now. When I first tried them I nearly went out thru the windscreen. I adjusted the vacumn to around -15psi which just gives me the right brake assist for the way I drive. All in I'd say the above conversion has cost me around £130, this is no9t including the calipers or disc's. Dave

[Paul93Lotus]

How is that set up as far as lock up?  Did you repipe the rear wheels individually on their own circuit or just left the existing "y" to the rear and operate them with equal ressure off of the original piping? Do you have any adjustment to the brake bias? I guess the only reason I wanted to swap everything was to maintain a working abs system, and I hate the pedal feel from the Delco.  I was thinking of using a bosch vacuum pump as used on turbo audi A4's isolated with rubber bushings, a vacuum reservoir and check valve with a pressure switch to turn off the pump, as well as piping the engine vacuum to the reservoir as a back-up....similar to the GT3 set up with the later KH system.

[andydclements]

I'm not convinced that little Bosch pump delivers the vacuum fast enough in the event of repeated pedal depression, I've got a pump that is specifically for brake boosters, complete with it's in-built pressure sensor and controller. It's quite large compared to the Bosch unit but should give me the ability to press and release the pedal in the event of needing to perform an emergency stop (and yes, I have had to do manual Anti-lock braking and it really takes determination to take your foot off the pedal when all you want to do is stop the car).

The pump I have is very similar to the ones used in the USA on truck restorations.

[Giniw]

Hi and sorry for the up, but @Paul93Lotus, have you eventually made the conversion?

Edited October 22, 2019 by Giniw

[achim212]

Hy,

I made the conversion to KH 415,the brake feel is very nice.

[Giniw]

Thanks @achim212! This looks rather neat! =)

Did you manage to source an original servo? (and the abs pump and its brackets which looks like new!)

[achim212]

Hy,

The servo and the bracket was used from V8,the abs unit and the master brake cylinder is new

[Paul93Lotus]

Glad to see that you were able to make it work!.  My car's delco abs gave up the ghost after my last smog check on the way home - at first I thought it was just the dyno reaction (where only the rear wheels moving triggered the abs light) but on the way home I lost my assist,  Been parked since July before last.

 

Did you encounter any issues wiring in the Kelsey Hayes system - were you able to get the abs functioning as it should?

[achim212]

the wiring was easy,and the abs works fine

 

[sanj]

13 minutes ago, achim212 said:

the wiring was easy,and the abs works fine

 

What vacuum pump are you using, and how do you regulate it? Thanks!

[achim212]

Hella UP 30 A0004302832 Volvo XC90 30645383

[Paul93Lotus]

Achim,

 

The Volvo part number you posted in your last post was for a power brake booster switch - is that number correct in that you used that to switch the vacuum pump on and off?  I am finally getting off my ass to deal with this DM III problem and do the retrofit to an EBC 430 as my smog check is due in July and my car has sit from procrastination.  Any part numbers you used for the switching of the vacuum pump would be helpful - I already have the vacuum reservoir.  Did you just add a new brake line along the chassis to enable 4 wheel abs - was that difficult running it through the bulkhead to the backbone of the chassis?  Any challenges you had while installing would be good to know.

Thanks - Paul