ABS Problems - advice needed

[burbel]

It seems that my ABS pump (1992 NSX, 108k miles) is running for around 10 seconds every so often (say every minute or two) while driving around. I don't notice it all the time, but normally drive with my windows down, and have noticed it a few times lately.

I also thought that I could smell a light burning smell 2-3 times recently, but I'm not sure, as I was in traffic each time.

When I got home and pulled the cap to the ABS reservoir, I noticed that the fluid was bubbling slightly on the right side; when I pulled the plastic filter out I also noticed what looked like a bubble on the right side.

I bought the ABS T-bleeder tool awhile ago to flush the brakes, but haven't gotten to it recently.

Was wondering what you all think it could be, what I can try and do to fix it myself, etc. I checked the FAQ under troubleshooting, and just took the car out for some serious lockups on a back road (no gravel or grass that I could find nearby), but didn't notice a difference.

On a related note, until I find out what this is and fix it, would you all recommend that I disable ABS every time I drive the car now (the parking brake trick)?

Thanks in Advance!!!

 

[pacacu]

I have the same problem on my 91 with 28000 miles. I had braking system bleed at the dealer but found out there is a slow leak. encountered the same problem with fluid bubbling. also tried many hard braking action.
Verdict: replace the ALB modulator assembly and a hosts of other ABS fittings, plus renew the master brake cylinder at the same time. Per discussions with Japan NSX club, this is due to old age and not the mileage. It is very expensive as the whole fix will cost you close to US$ 5k. However, the pumping is frequent but still not triggered the ABS lite to come out and fluid need to be checked frequently. One can defer the fix till the lite com on. The system is still workin till then.
good luck.

 

[Larry Bastanza]

This sounds like the typical "stuck selonoid". Change the fluid, bleed it with the tool, then go out and exercise it.

I would be reluctant to "go for an abs system" replacemnet yet. There are a few small items that can be done. The seal on the accumulator could be leaking. Do you see fluid under the accumulator ball? If you see fluid coming from the TOP of the ABS reservior it is most likely due to a stuck selonoid.

If the ABS pump stops after ten secondsa and you get no ABS light, then the system is just having a hard time holding pressure. This is one of two things, stuck selonoid, or bad seal. The only way you would have to replace the ABS system is if a stuck selonoid cannot be "unstuck". You can check out www.danoland.com and check out DanO's DIY ABS bleeding procedures to understand all the ways to "unstick" a seloniod. His writeup is excellent, I use it regularly.

HTH,
LarryB