Posted December 8, 2024Dec 8 comment_672119 I have one that keeps pumping down, would like to try a different one. If you have some you dont need let me know what you want for them. I have tried cleaning, just one keeps failing. Not a big deal as it quickly pumps up, but i would still like to try with a different one. Link to comment https://www.classiczcars.com/forums/topic/69183-p90a-hyd-pivots/ Share on other sites More sharing options...
December 8, 2024Dec 8 comment_672120 Do you have a part number? Link to comment https://www.classiczcars.com/forums/topic/69183-p90a-hyd-pivots/#findComment-672120 Share on other sites More sharing options...
December 8, 2024Dec 8 comment_672121 @Dave WM Did you post the ad in the wanted classified? I don’t see it there with possibly a description of what you are looking for. Reason I ask is there hasn’t been ads there for awhile since @Mike introduced an upgrade. Just asking… Link to comment https://www.classiczcars.com/forums/topic/69183-p90a-hyd-pivots/#findComment-672121 Share on other sites More sharing options...
December 8, 2024Dec 8 comment_672154 You might also have success at hybridZ. Many convert their heads to solid pivot heads Link to comment https://www.classiczcars.com/forums/topic/69183-p90a-hyd-pivots/#findComment-672154 Share on other sites More sharing options...
December 9, 2024Dec 9 Author comment_672170 do not have the parts catalog for that one. It maybe a weak spring inside the lifter. My take on how it works is if the cam lobe is left down at shut down, the lifter will bleed out under the load of the valve spring. BUT as soon as the cam lobe rotates over it "should" lift the internal piston pulling oil thru the one way valve on the bottom of the piston, thereby filling the lift. Now IF the spring is weak it may not be able to exert enough pressure to overcome the viscosity of the oil to draw up thru the check valve. I may end up comparing a spring tension to a known good to see if I can confirm this. Not really interested in converting to manual since I like the way the valve mechanism works when it works correctly. Worse case is I do nothing and it ticks for a few seconds until the oil pressure overcomes the one way valve and it "pumps up" on its own. I do notice times when there is NO tick on startup, again I think this relates to the cam lobe random stopping position, that is if no load then the pivot never bleeds down in the 1st place due to lack of pressure from the valve spring.  Link to comment https://www.classiczcars.com/forums/topic/69183-p90a-hyd-pivots/#findComment-672170 Share on other sites More sharing options...
December 9, 2024Dec 9 comment_672171 You could try something like Rislone. I use it in my BMW's sometimes when the valvetrain is noisy Link to comment https://www.classiczcars.com/forums/topic/69183-p90a-hyd-pivots/#findComment-672171 Share on other sites More sharing options...
December 9, 2024Dec 9 comment_672172 Btw, I wasn't suggesting for you to go solid lifter. I was thinking there might be some hydraulic ones available at hybrid Z from them going to solid lifter Link to comment https://www.classiczcars.com/forums/topic/69183-p90a-hyd-pivots/#findComment-672172 Share on other sites More sharing options...
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