• Protip: Profile posts are public! Use Conversations to message other members privately. Everyone can see the content of a profile post.

Abs solenoid, is clicking important or ohm reading?

Joined
17 March 2004
Messages
158
Location
New Jersey
Hello Everyone,

I got the dreaded ABS Light after I drove over 6 mph, pump activated for 120 seconds, then shut down, and tripped the ABS light on the dashboard. I first got this ABS light about a year ago....as the car sat through the winter months, I did not notice the light when warm weather hit.....thinking it must have been a fluke. Now that it is getting super cold in the Northeast, the light is back.

I didn't have the bleeder tool, nor could I buy it or would anyone lend it to me. So, I tried danoland's solenoid flushing technique, but I never heard one solenoid click, fluid return to the modulator reservoir or anything. dead silence! All four solenoids. I checked the pressure switch for continuity, and there was no continuity AFTER bleeding the pressure from the bleeder valve. Unfortunately, after relieving the pressure with a 9mm box end wrench and flexile hose ( btw, I collected 215 ml.....clearly not within the spec of our accumulators. I believe it should be between 100ml-160ml. I was like oh great my accumulator probably has a ruptured bladder., I tried activating the pump by jumping the pump fuse to check the pressure switch for continuity once the system became fully pressurized. Guess what? I ran the pump for 30 seconds, waited 2 minutes and ran it again for 30 seconds. I figured I would try to bleed the system down via the bleeder valve and guess what? Not a drop of fluid. So of course the pressure switch didn't have continuity. Now, I should tell you when I drained off the fluid initially, it was orange in color. But when I got to the end, a grayish dark fluid was expelled! I was like, maybe this is the disintegrated bladder from my accumulator. So, I decided to pull the entire ABS system out and pull the accumulator out and when I removed the three fastening bolts, the orifice was covered in muddy sludge. I cleaned the little bit out. I have read many posts, including responses on our ABS system. One thing I could never find in any of the posts was the depth a probe would reach into a "good" accumulator. I measured mine and it was a little over 1 inch. It held about 17 drops of brake fluid which was kind of strange. Is this normal? Kaz said the 215 ml of brake fluid that was bled off maybe insufficient back pressure from the nitrogen behind the bladder and clogged pathways for the lack of repressurization.....Has anyone ever measured a healthy bladder? If so, please post here so future prime members have a reference point too.

So, I decided to pull the whole ABS unit out of the car. My left most screw in the modulator reservoir (side closest to the lower pressure hose) was corroded. So, needless to say I had to drill the head off to get the reservoir off. I removed the other screw inside the reservoir and the one on the modulator without any issue. I eventually got the top assembly off of my solenoids but after 2 days of banging on it with a rubber mallet. So, if anyone has this problem, please pm me and I will assist you anyway I can, since another prime member wouldn't simply answer whether or not the left most screw held the modulator cap on. Because the pictures don't say so, but after banging on it for two days with a rubber mallet and pulling like a monkey on the modulator cap, it gets you wondering!
Needless to say, I found nothing but crystallized flakes of either assembly grease or probably brake fluid. I couldn't determine what it was. Two of the solenoids that don't have screws that hold down the top assembly, had a layer of dried translucent solids. I was like, let me clean these things up. Herein lies my question. Kaz, asked me to do a resistance check on all 8 valves, as he so lovingly points out, thanks Kaz! They all checked in between 2.9 ohms and 3.0 ohms. I presume this is normal? Has anyone tested the resistance on their solenoids? So, I decided to apply 12V across the solenoids once more. I further tested the solenoids and found that when I applied 12V to each valve I got the following "clicks"

RR Red Wire-Click Yellow Wire-Click, GREAT! There was no click ever before when the whole ABS was in the car
FR Red Wire-NOTHING Yellow Wire- Very Faint Click, "defective?" solenoid
RL Red Wire-NOTHING YellowWire -Click, "defective?" solenoid
FL Red Wire-Click Yellow Wire-Click, GREAT! There was no click ever before when the whole ABS was in the car

Could the FR and RL solenoids be gone even though resistance is the same as all others or am I putting too much emphasis on the Click sound? Or is resistance the deciding factor of good vs. bad solenoid? I don't want to have to reinstall the entire unit and find out that my Front Right and Rear Left Solenoids are not working. I figured I would ask before embarking on an entire reassembly, brake bleed, etc.

Btw, before I am told to exercise the solenoids like 20 or 30 times, I think I have activated the solenoids close to 100 times on the "defective" ones, with sufficient rest between each on/off cycle so as not to overheat the solenoids. I carried out this procedure with the bottoms submerged in new brake fluid and out of brake fluid. The front Right solenoid has been sitting in new brake fluid for 2 days now, hoping maybe some sludge or something might get dissolved and free up the solenoid and allow it to function properly. Anyone have experience on our Sumitomo made solenoids? We can't exactly open them up to give them a good cleaning. I even tried placing the solenoids in a warm bath, with the bottom quarter submerged in brake fluid in a beaker to maybe help dissolve any potential gunk on the valves inside the solenoid. Any other recommendations? Or am I screwed?

Any help from you guys would be appreciated. Btw, Kaz, thank you so much for your help on this forum!

Btw, I noticed that my master brake cylinder reservoir drained all of it's fluid when I pulled my ABS out. I thought these fluids were not supposed to be connected to one another.
 
Last edited:
Last edited:
Another method to help with a stuck solenoid is to use a bit of compressed air. Not many people have done this, but it has worked for some stubborn valves/solenoids. others have also disassembled the solenoids.

http://www.nsxprime.com/forum/showt...h-some-help-from-a-RHD-ABS?highlight=solenoid

http://www.nsxprime.com/forum/showthread.php/162710-ABS-ALB-modulator-rebuild-write-up/page7


Hey Warren,

Thanks but it seems like the pic on page 7 is that of a valve disassembled. I will try the compressed air on my two nonclicking solenoids. I just don't know how much psi is safe with compressed air going into the solenoid port. Thanks!
 
Last edited:
Back
Top