Results 1 to 13 of 13

Thread: Will a 97-99 abs modulator work in a 91?

  1. #1
    Registered User BrianB's Avatar
    Join Date
    Feb 2013
    Location
    Georgetown, DE
    Posts
    191
    Feedback Score
    0

    Will a 97-99 abs modulator work in a 91?

    A friend of a friend has a new 97-99 abs modulator for sale cheap. Will it work in my 91? I noticed its a different part # but didn't know if it was just a newer revision. The reason I'm thinking of replacing it is that every once and awhile the abs unit will over flow with fluid. I had a flush done and it helped for a short period. Or is that a accumulator issue? Also it will run after backing out of the driveway 50% of the time.

    Thanks,
    BrianB

  2. #2
    Registered User shawn110975's Avatar
    Join Date
    Jul 2009
    Location
    Tampa,FL
    Posts
    6,521
    Feedback Score
    23 (96%)
    it will work with an wire harness adapter from SOS,

    then you need all the front brake lines and the oem y split the hardest one to install is the passenger front brake line its like 6 feet long it bends and turns etc to get to the pump

    good luck

    - - - Updated - - -

    you will also need the new ABS PUMP housing which hold it to the frame rails cuz its different on the newer NSX's
    " A man that does not smile should not have a shop"

  3. #3
    Charter Champion Larry Bastanza's Avatar
    Join Date
    Feb 2000
    Location
    Warwick, NY, USA
    Posts
    5,713
    Feedback Score
    16 (100%)
    The 1997-99 in a 1991 does not require the SoS harness, that would be if the replacement was a 2000+(newer type system with no fluid). The 1997 is the same type as the 1991 system, but there are a few differences(reservior is slightly modified). I really think it is a bolt on replacement but I am not 100% sure. Will be back to you, once I can research it.

    Regards,
    LarryB

  4. #4
    Registered User BrianB's Avatar
    Join Date
    Feb 2013
    Location
    Georgetown, DE
    Posts
    191
    Feedback Score
    0
    Thank you both for the input! Shawn110975 I think your thinking the newer version. I wish I could find it at the deal I'm looking at for this one. LarryB I think your right, it physically looks the same except possibly the reservoir. Would this solve my overflow issues? I had decided to put it off until I got a 02+ version but with this option presenting itself if it will work its the better deal by far. He wants 400.00 for a brand new in the box modulator.

    - - - Updated - - -

    I bought it tonight before someone else did... It looks almost identical. LarryB if you find anything that I might need to do or that it won't work please let me know. I figure worst case if I had to because it wont work, I could sell it on prime. But hopefully it will work.

  5. #5
    Charter Champion Larry Bastanza's Avatar
    Join Date
    Feb 2000
    Location
    Warwick, NY, USA
    Posts
    5,713
    Feedback Score
    16 (100%)
    Frankly, this is such a common issue, it is the same for all versions of the unit. The problem is it does not get used, then it gets stuck. It is a mechanical plunge in a bore, and after a long time of not moving, it moves once, then gets stuck in the bore. I have talked about the need to "exercise" the system many times. I have NEVER had to replace one, in order to get it to work, and I have had many that come to me stuck. If it gets stuck, first thing to do is get the car on a slippery surface and "work" the ABS, get the pedal to kick back at you a few times, and it will settle down. Good luck with it. LMK if you have any qeuestions.

    Regards,
    LarryB

  6. #6
    Registered User BrianB's Avatar
    Join Date
    Feb 2013
    Location
    Georgetown, DE
    Posts
    191
    Feedback Score
    0
    LarryB,

    Thank You for the help! I think this might be a project for late winter/early spring. I have tried to exercise them and it seems to help get me by for a little then it sticks again. Hopefully the new one will last awhile before sticking.
    BrianB

  7. #7

    Yes it will

    A straight & simple swap that I did 2 years ago. If I understood the UK guru Kaz correctly, the 2nd generation Nissin modulator unit, although similar in appearance, is different & less prone to pistons sticking.

  8. #8
    Registered User OLDMNSX's Avatar
    Join Date
    Oct 2005
    Location
    Boise, Idaho
    Posts
    825
    Feedback Score
    15 (100%)
    Items for Sale
    The NSX ABS system has three variants of modulators. The first two will interchange, i.e. bolt on. The third gen is like "Larry B says" 2000+ and is a little spendy. I have replaced my first gen ('91) with the second gen and am not sure that it is really any better than the first. Again, like "Larry B says" excercising the solenoids is the best medicine for the first and second gen ABS.
    If you don't put your car into "Deep Storage" for the winter and you live in an area that gets snow covered roads take your NSX out in your neighborhood and actuate your ABS......A LOT!!! I am in Afghanistan and that was the last thing I did with my NSX before I put it into "DEEP STORAGE" last January.
    The other option is to build the tools to do a flush and cycle of the ABS system, or get someone who has them to loan theirs to you.

  9. #9
    NSXPrime Gold warrenw's Avatar
    Join Date
    Sep 2007
    Location
    Edmonton, AB, Canada
    Posts
    1,716
    Feedback Score
    6 (100%)
    Like always, Larry and Brad are correct.
    That 1997 modulator is a complete swap. The solenoids are the same so everything else should be fine.
    However the two control units (behind the glove box) have different part numbers:
    1991 ABS control unit: 39798-SL0-003
    1997 ABS control unit: 39790-SL0-023
    The difference? Who knows?
    Last edited by warrenw; 12-05-2013 at 07:09.
    Warren Woodcox
    ________________________
    '02 Suzuka Blue / Blue S2000; '91 Formula Red / Black NSX
    '09 Toyota Tacoma; '06 Nissan X-Trail

  10. #10
    NSXPrime Platinum Kaz-kzukNA1's Avatar
    Join Date
    Jun 2011
    Location
    Bucks, UK
    Posts
    61
    Feedback Score
    0
    Hi, BrianB.
    For the history of ABS on our NSX, please refer to the following link on NSXCB site.

    http://www.nsxcb.co.uk/showthread.ph...5279#post75279

    The photos are based on RHD model so the orientation of the modulator and the position of the hard line fittings would be different from those of LHD models but you will get the idea.


    From hardware point of view, apart from the obvious difference in the shape of ABS reservoir, you may not be able to tell the difference in the solenoid package between the 1st and 2nd gen ABS.
    2nd gen has better protection against the contamination around the solenoid body and this is the one you bought.
    As others mentioned, you can install the 2nd gen system in place of your original 1st gen one.

    However, you need to be aware that there are two different ABS setting within the 2nd gen system due to the introduction of the larger caliper/disc design from 97 onwards.

    I don’t know which version of 2nd gen ABS you bought but the ABS pistons and the balancing springs for the rear brake are different compared to the early 2nd gen model and you won’t be able to tell the difference from the outside.


    From software point of view, again, the ABS controller was changed (as per warrenw’s post above) due to the above reason but the main reasons were the changes in ABS warning light circuit, extra error codes, chassis loom, etc.

    Therefore, unless you modify your chassis loom, you will be forced to use your existing ABS controller on your 91 model even when using the 2nd gen 97+ spec ABS.

    It will be plug and play and it will work but strictly speaking, the ABS setting won’t be the same if you bought 2nd gen 97+ ABS and if you are still using your original 91 brake caliper/disc design.

    Having said this, the brain power and control of 2nd gen (including the 1st gen) ABS are so primitive and considering 99% of the ABS usage would be under panic braking situation, you won’t notice the difference between the ‘pre’ and ‘post’ 97 classic 2nd gen ABS setting.


    You will only notice the huge improvement once you upgrade it to the latest one-body Bosch style ABS that can be seen on 99+ (I don’t like using the year model so some will call it as 00+ depending on the country spec) NSX.

    The reaction time and control detail have improved so much that you will never want to go back to the classic ABS.

    If you have access to the skid pad, you can test one of the major loop hole in classic ABS but it is out of the scope for this thread so I’ll leave it for another time.

    Kaz

  11. #11
    Registered User BrianB's Avatar
    Join Date
    Feb 2013
    Location
    Georgetown, DE
    Posts
    191
    Feedback Score
    0
    Thank you for all the info! I have the 97 modulator now. But I haven't installed it yet, I don't have the abs bleeder tool so I'm thinking I will switch them out leave my abs fuse out and take it to the dealer to bleed? Or is it not too bad to bleed the abs. I know how to bleed my normal brakes which I did during my brake line install. Should I run super blue in my abs as well?
    BrianB

  12. #12
    NSXPrime Platinum Kaz-kzukNA1's Avatar
    Join Date
    Jun 2011
    Location
    Bucks, UK
    Posts
    61
    Feedback Score
    0
    If you have lots of time, brake fluid, turkey baster and patience, eventually, you can flush and bleed the ABS without the T wrench (ABS bleeder tool).
    There are lots of ‘how to’ articles for ABS here on Prime and also in http://www.danoland.com/nsxgarage/brakes/abs/abs.htm
    Not conclusive but you will get the idea.

    However, based on your ‘Location’ info, you are based in US so you can get OEM parts at very competitive price with even free delivery so if you are thinking of keep using the classic ABS (1st and 2nd Gen.), then it will save your time as well as support you in diagnosing future ABS issues related to the accumulator by getting the OEM T-wrench.

    Bleeder, T-wrench: 07HAA-SG00101

    It used to be about US$110 or less inc. discount with free delivery but now it seems to be about US$150.

    The initial investment may seem high for what it does but if you use it once a year or two for many years, it’s worth it.

    Unless you have recently bled your main brake system and has enough left over of the super blue, there is no need to use so called ‘racing brake fluid’ for the ABS. (By the way, please check the legality of blue coloured brake fluid in US.)

    ABS fluid is separated from your main brake system (master cyl, master cyl reservoir, caliper, brake line, etc) and it won’t get hot so just plain ordinary DOT3 or 4 is enough. At the end of the day, it’s DOT spec.
    To keep your ABS healthy, it’s more important to exercise the ABS regularly or even better, flush the accumulator and activate the solenoids manually every year or two than using special brake fluid for ABS.

    Kaz

  13. #13
    Registered User BrianB's Avatar
    Join Date
    Feb 2013
    Location
    Georgetown, DE
    Posts
    191
    Feedback Score
    0
    KAZ, Thanks for the info!
    BrianB

Similar Threads

  1. Will a 2005 Climate Control Unit work in a 1991?
    By sjones in forum NSX Owner Discussion (1st Gen)
    Replies: 3
    Last Post: 06-14-2006, 16:50
  2. will door speakers from a 98 work in my 92?
    By Alixp81 in forum NSX Do-It-Yourself (1st Gen)
    Replies: 1
    Last Post: 02-03-2006, 15:49
  3. Will a 2000 ABS unit work in my 91
    By whrdnsx in forum NSX Do-It-Yourself (1st Gen)
    Replies: 5
    Last Post: 07-23-2005, 06:30
  4. Will 98 cluster work in my 91 NSX??
    By Polo in forum NSX Owner Discussion (1st Gen)
    Replies: 3
    Last Post: 11-05-2003, 08:21
  5. will 97+ oem nsx headers fit in a 91-96nsx?
    By madfast in forum NSX Owner Discussion (1st Gen)
    Replies: 1
    Last Post: 07-14-2003, 09:20

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •