Not another ABS 'Solenoid' Thread ;) ABS Pump and pressure relief valve

Joined
24 September 2011
Messages
216
Location
Irvine, CA
Hey Guys,

Hope everyone is doing well. I for one, have been able to get after a number of NSX projects I've been putting off! steering tie rod and endlink, new rear fender liners, front radiator air guide, ect.

HOWEVER, the ABS has got me stumped. After pouring over pages and pages of stuck solenoid treads (Dano, Kaz, ect) and I did all the typical fuse checks, trigger and solenoid flush methods without success. I then tripped over a post from midnight blue on http://www.nsxcb.co.ukhere and it aligned with exactly what I was experiencing. New to that forum so no posting or messaging ability yet... Pump runs at 6mph and times out but if jumped and solenoids are triggered, no fluid movement or drop in fluid levels within the reservoir.

Decided to pull off the pump and check it out and here's what I found.
Within the 'relief valve' (?) (not shown exploded but within the #10 grouping in the exploded parts diagram here), there is a floating plunger of sorts but here's where it gets fun, upon removing I noticed it was jammed at a slight angle as seen here. Took some effort to separate the two pieces, but once it did, I attempted to put them back together and sure enough they stuck/ snapped together again. As seen it the video, at about 11 o'clock mark you can see a slight flat spot in the lip.


Now I'm curious if this is an intended design or perhaps this one became damaged? Looking into the bore, there appears to be a slight scare on the wall likey from the crooked valve seen here. Before I attempt to separate the pump motor from the pump I wanted to gather any thoughts the community had. much appreciated!


Part numbers here should anyone need them.<style type="text/css"><!--td {border: 1px solid #ccc ;}br {mso-data-placement:same-cell;}--></style>
 
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one step forward two back... cute little in/lb tq wrench ;)
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Got everything back together but for some reason I'm not getting any fluid to the pump. Ppened the bleeder, ran the pump, toggled the solenoids and no luck. Even bypassed the reservoir with a syringe full of fluid and the pump refuses to take fluid :? Didn't separate the motor from the pump, so that might be the next place I check..

Made a mess with brake fluid, so I'm taking a beer break for now..

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Back again!

So as I mentioned, upon reassembly there was no fluid movement or pressure. Out came the pump again but this time decided to take it down past the check valve. Took some effort to pop out this piece which I can assume the pump makes contact with allowing the spring to compress allowing pressurized fluid to pass as the spring collapses.
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However, I believe mine may be jammed. Check out the videos and let me know your thoughts! thanks!



 
definitely the piston is jammed,the spring is compressed and the piston is in.In normal condition you should be able to press the piston and compress the spring very easily with a finger. push the piston from the other side of the spring side,clean and lube everything
 
definitely the piston is jammed,the spring is compressed and the piston is in.in normal condition you should be able to press the piston and compress the spring very easily with a finger. Push the piston from the other side of the spring side,clean and lube everything

thanks a millon!
 
just an update for anyone following, Patatina was right about the piston! when looking at the piece that appeared as one but sure enough after popping it back in the cylinder and tapping it lightly it sprung open! the pump makes much more sense this way ;) cleaned it out (may debur if needed with some white scotch brite or 2000 grit) and now just xtrying to get a hold of some castrol (miller's or fuchs) red rubber grease for the reassembly. Not sure if this is needed as brake fluid likely will keep it lubed? Will document the reverse process for anyone who runs into a similar issue.
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