hi guys,

I am in the process of restoring my braking system on my Z and recently I found out that the later model ABS pumps/modules in the 300ZX's don't require bleeding which in my mind would be a great way to not just reduce the service time and maintanence of my braking system in the future with this later model abs pump setup but also completely remove the chance of me accidently spilling brake fluid from the pump into the cabin of the car during the old early model brake bleeding procedure if I ever need to bleed my braking system in the future.

I have already purhased a later model ABS pump model from Japan as well as acquire all of the metal hardline pipes from the pump to the union box in the rear hatch so I can easily remove my original early model abs pump and put the later model pump in without any modifications needed which is great.

The question i have is has anyone every done this kind of modification before on an early model 300ZX with a later model ABS pump. Im confident that it is possible because the pumps are pretty much the same with regards to their inner workings from my research on how ABS pumps work in general and the main difference with the early model compared to the later model abs pump is that the early model abs pump has a pair of bleed nipples on the top of the pump whereas the later model abs pump has no bleed nipples at all.

I also checked the FSM's electrical wiring diagram of both the early model and later model ABS pump circuits and yes the later model wiring diagram has more ciruictary to the abs system in it but from what I can tell the extra wiring contains just more fuses and orwarning relays or components of some kind and when I compared the ping layout and numbers for the early model and later model ABS pumps that connect to the pumps directly, they are the exact same pin layouts in the exact same location on both pumps and when I traced the wires from the pumps to the ABS ECU's, the pins numbers connectedt to the same exact pins on both early model and later model ABS ECU's. the only small difference I could see was that the pin location for the later model pumps to the ECU where in slightly different locations but they still used the exact same pin numbers.

I know the ABS pump is an important safety component of the car's braking system and I dont want to install the later model pump and potentionally disable the abs system due to a mismatch of components and I just thought id ask the more knowledgable 300ZX owners on here first before I go swapping in the new abs pump.

if anyone has any insights that would be much appreciated

You have clearly done some good background tech information but I am unclear why you would consider the later unit just because it does not have bleed nipples.

The abs unit sits high in the car relative to the other parts of the brake system and as such naturally is best placed to get an air out of the system.

Also a real benefit is any work done on the brake system before the abs unit including the front to rear pipework and the master cylinder itself can be done easily and only needs a short bleed at the abs unit without disturbing the wheel calipers or pipework, also an added bonus is been able to bleed the cross lines separately if required.

I think also the ability to change the master cylinder without causing issues with the other parts of the system is a real bonus.

The Abs system control module also has the build in diagnostic that matches the loom pin out on the unit, its not clear if this will still be functional.

As the zed production continued on after 1993 and 1994 the Nissan car company were in financial troubleand as the z32 was not really a huge monetary maker for them to continue production cut backs had to be made.

These cut backs are evident in the later cars with basic cord carpeting, ommission of the turbo gauge from the cluster and serious lack of undersealing. Other area such as the automatic climate control displays were dropped for the more basic manual non display controls.

Many of the later cars went back to cloth seats although they looked like a nice upgrade from the old grey or blue cloth seats that some earlier models were fitted with it was basically the same cloth just dyed a different colour.

The series two models with leather heated seats and alcantara door panelling were among the best spec.

I think the abs unit was changed to save money as it was a cheaper unit, and very likely taken from a Nissan model in production at that time.

Good luck going forward what ever you decide but for me I think its a backward step.

23 minutes ago, JeffTT said:

You have clearly done some good background tech information but I am unclear why you would consider the later unit just because it does not have bleed nipples.

Hey jeff i want to first thank you for taking the time to respond to my query on the possiblilty of swapping in the later model ABS pump into an early model 300ZX. I have tried my best to cover all of my bases because I know that the ABS system is a very improtant compoent to have on any car and could save my life one day knock on wood. I have never wanted to mess around with the braking system on my car for years because of that fact but now I'm in a situation where I am more experienced and more knowledgeable mechanically wise and I think I have done enough research to know this is a modification appears on paper to be possible but I know that there are still many things that I just don't understand mechanically and eletrically on a car yet and thats why I thought Id ask the question because if someone else had done this before and it worked without any issues then I know I was right with my research.

As I said in my initial post the time saved not having to bleed the system from the pump would just simplify the braking bleeding process and I see that as a big win for a DIYer like myself. But there are other several reasons as to why it could be a good thing to swap over the ABS pumps beside just the fact of not having to bleed the pump as I mentioned. For one if a later model car has a failed ABS pump, knowing that a early model ABS pump could be installed as a replacement and function without any issues could be a big win for any later model owner who would have to find and purchase a replacement ABS pump and if either the early model and or later model pumps become more rarer and or harder to find at least there is an option to use either pump and repair the car for that owner as one adiditonal reason you could say is a good thing to know.

29 minutes ago, JeffTT said:

The abs unit sits high in the car relative to the other parts of the brake system and as such naturally is best placed to get an air out of the system.

Also a real benefit is any work done on the brake system before the abs unit including the front to rear pipework and the master cylinder itself can be done easily and only needs a short bleed at the abs unit without disturbing the wheel calipers or pipework, also an added bonus is been able to bleed the cross lines separately if required.

I think also the ability to change the master cylinder without causing issues with the other parts of the system is a real bonus.

The reason I even considered this modification was because back in Decemeber of 2024, I was investigating a strange grinding sound coming from my front brakes. In the process I reseated all of the front brake pads in both of my later model Iron front brake calipers and then attempted to bleed the braking system of air as you do. But I came across a problem as for some unkown reason after bleeding my brakes mulitple times, I just couldnt get a firm brake pedal feel. What follow was several days of multiple brake bleeding attempts on the entire braking system using various methods of bleeding including pressure bleeding, manual 2 person bleeding and even vacuum bleeding and after 12 bleeds of the system, I still couldnt get a firm brake pedal feel.

After 2 months of diagnosing the problem I eventually figured out that the reason I was having this issue was because many years ago when I change over my brake rotors to new a set of rotors, I had accidently installed both of my front calipers on the wrong side and that meant that instead of the brake bleed nipple being on the top of the caliper, it is now on the bottom and so no matter what I did, I was never going to get all of the air out of the system and so I have solved my problem in theory.

During the whole bleeding process sage I went throught, I had considered that maybe the problem could be caused by a bad or failed ABS pump which I thought was highly unlikely but I couldnt rule it out completely and because we had to bleed the system multiple times and considering the car had sat for 3 years, we thought maybe there was a stuck valve or trapped air inside the ABS pump causing our issue. So I was thinking of replacing the ABS pump in an attempt to solve the problem and when I found out that the later model pump didnt require it to be bleed I saw an opportunity to install a part that would save me a ton time of time during regular maintenance of my braking system.

Even though I now know that the issue wasn't due to my ABS pump being faulty in any way, I still like the idea of not having to bleed the pump of air in the future and would make bleeding the braking system require less steps to complete and makes it whole bleed process a little less complicated.

1 hour ago, JeffTT said:

The Abs system control module also has the build in diagnostic that matches the loom pin out on the unit, its not clear if this will still be functional.

This is the biggests quesiton mark for me as to whether this modifcation is possible or not. As I said in my post that though wiring diagrams between the 2 systems are different, the pins for the ABS pumps are the exact same and the pins on the ECU's are the same but in slightly different locations. There is no real way for me to determine from the wiring diagrams whether or not the sysem will work electronically wise and thats why I was hoping that amybe someone else has already to this modification in the past proven it is possible and works. If I don't find that answer I may have to be the first guinea pig out of all of us to try it and see if its possible.

1 hour ago, JeffTT said:

As the zed production continued on after 1993 and 1994 the Nissan car company were in financial troubleand as the z32 was not really a huge monetary maker for them to continue production cut backs had to be made.

These cut backs are evident in the later cars with basic cord carpeting, ommission of the turbo gauge from the cluster and serious lack of undersealing. Other area such as the automatic climate control displays were dropped for the more basic manual non display controls.

Many of the later cars went back to cloth seats although they looked like a nice upgrade from the old grey or blue cloth seats that some earlier models were fitted with it was basically the same cloth just dyed a different colour.

The series two models with leather heated seats and alcantara door panelling were among the best spec.

I think the abs unit was changed to save money as it was a cheaper unit, and very likely taken from a Nissan model in production at that time.

Good luck going forward what ever you decide but for me I think its a backward step.

One of the goals I have for my 300ZX build if you havent been following it yet, has been to covert and upgrade my early model 300ZX to that of the very last production models from 1998-2000. I did this to try and moderise my 300ZX as much as possible but keeping it period correct and yes I know that Nissan did begin alot of cost cutting efforts on the later model 300ZX's to save money but they also did improve things on the car over its production run, an example would be the power transistor unit or PTU which was upgraded in the later model 300ZX's. Everyone knows the series 2 PTU is a smart upgrade choice for any 300ZX owner and so even though Nissan were cutting costs they were also upgrading the car's components and systems to make them more realiable.

Whether or not the ABS pump was changed to save on costs, I can't say but from my point of view Nissan might have changed over to the later model ABS pump because they could then save on maintence time and costs at the dealerships by not having to go through the brake bleeding process on the ABS pump on the later model cars but I guess we will never know the real reason.

I don't think it is a step back to upgrade to a later model ABS pump, though it might seem like a strange modification to yourself, I see people all the time boosting their cars for street use a big step back in my eyes, the 300ZX was built as a gran tourer not a lamborghini race car but most builds I have seen over the past 20 years are of people only wanting to try to make their 300ZX's faster and have huge horsepower goals. Each to their own and if thats what floats your boat thats fine but I see all of that crap as just adding risk to you crashing the car doing something stupid on the road where you might feel inclinded to race another car on the road or during a track event make a mistake and crash into a wall totalling the car just for the thrill of going fast. I don't have any ambitions to make my 300ZX another silly super fast race car 300ZX and Instead I want to build a unquie, one of kind OEM+ 300ZX that includs all of the latests technology and compoents for the car from the era it was made in as much as possible. I want to build a collector piece that has as many optional and rare OEM parts on it that don't exist anymore and also come from not just the JDM models but the USDM, and UKDM models as well make it the best spec'd out 300ZX in the world if you could of brought it back in the day. I see the later model ABS pump as an improvement over the early model pump becauase of the fact it doesnt require it to be bleed which might mean its a self bleeding pump when compared to the manual bleeding pump from the early model I dunno but thats just me and you can agree to disagree with me on that which is totally fine.

All I need to know is if its possible to swap it in and then not have any issues mechanically and or electrconically wise after the swap?