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

Accusump leaking

Joined
15 October 2002
Messages
4,798
Location
West Vancouver
Since I pulled my car out of winter storage (in my garage) and started driving it, Ive noticed that my Accusump is leaking.

It appears that the leak is between the pump and the valve, though the threads that connect the two. It appears to be a very slow leak (ie, slow enough that I dont notice any leaking during a drive, but only when I leave it overnight or while Im at work). Ive been closely monitoring my oil levels and theyve been fine (although I have topped up).

Preliminary evidence suggests that I can stop the leak by discharging the oil from the pump when I turn the car off. It appears that the high pressure in pump is forcing oil out slowly before the valve.

Pic of the set up is below.

I suspect that the problem was my negligence in purging the pump over the winter. I never thought about it; was never told that I should. But it makes sense that any high pressure system is going to be under increased stress as the temp drops. I bet I blew a seal or something in there. Tightening doesnt do anything to stop the leak.

Anyone know what I should do besides the obvious of bring it somewhere?

photo-27.jpg
 
Installation.

Those NPT fittings are not threaded in properly, having inadequate engagement length. I can tell just by looking at the gap between the sump and the pressure relief valve, EPC valve and adapter.

The oil system is under relatively high pressure. What you are seeing is the teflon tape getting slowly saturated by a leakage path in the NPT threads.

I think you should take it back apart and re-install it.
 
Looks like a little bit of tightening has cleaned up the seeping. I cant tighten it anymore because the valve is up against the safety valve, but the seeping has stopped (it seems). I have a sneaking suspician that the metal hosing is under stress in a way that it has been unwinding the valve, so I took a metalic marker and lined all of the connections back there so I will be able to tell if it twists itself loose again.

For future searchers. John was correct, not enough thread engagement, although I just turned it 1/2 to 3/4 turn.
 
Tighten the main valve into the body before you install the pop off valve, this will help. I use liquid teflon thread sealer instead of tape. Seems to be more consistent as far as results.

Glad to see your problem was simple to fix!

Dave
 
I am having the same problem. I ended up taking John's advice and tore out the pump and reinstalled both the relief valve and main port fittings. I read in the directions to use teflon tape ONLY. I'm sure they just don't want the introduction of any contaminate to the inside of the cylinder, but I took their advice.

Upon doing the breakdown, I noticed that the dirtier oil accumulated near the bottom of the stroke. I got some nasty and worrysome oil out of this thing. Should there be a periodic clean out of the Accusump for maintanace reasons? Obviously this is a great place for unfiltered contaminats to hide out.

What PSI should we be seeing in loaded state? I'm only seeing 4.5K, about median for our normal system pressure.

Oh, and Dave, are you out there? I'm getting no response from PMs. :confused:
 
Why would you say this, the system pressure would drop, unless you mean that seals shrink?

I questioned that as well. We aren't talking about water here. A leak is a leak. Our relief valves are rated @ 150PSI while our system has a max of ~80PSI. Ther is no way that weather temp could cause such a response. Well, unless we drove the NSX into a volcano...
 
I am having the same problem. I ended up taking John's advice and tore out the pump and reinstalled both the relief valve and main port fittings. I read in the directions to use teflon tape ONLY. I'm sure they just don't want the introduction of any contaminate to the inside of the cylinder, but I took their advice.

Upon doing the breakdown, I noticed that the dirtier oil accumulated near the bottom of the stroke. I got some nasty and worrysome oil out of this thing. Should there be a periodic clean out of the Accusump for maintanace reasons? Obviously this is a great place for unfiltered contaminats to hide out.

What PSI should we be seeing in loaded state? I'm only seeing 4.5K, about median for our normal system pressure.

Oh, and Dave, are you out there? I'm getting no response from PMs. :confused:

Im limiting the leak by running the system active all the time. The leak was very slow, but was overnight, when the cylinder was at full pressure. Some oil found a way of sneaking through the threads near the valve (in the trunk). Now, the cylinder dumps pressure when Im parking the car when I get home - problem solved. I do have teflon tape on each connection.

Im seriously thinking of removing the Accusump over the winter. Not spending much time on the track anymore.

I dont see any PM's from you! You sure you sent them to me?
 
I dont see any PM's from you! You sure you sent them to me?

Ooops! Actually speaking of titaniumdave. I sent him a PM a short while back.

So far, after my rebuild, everything seems to be holding well. Now I'm wondering if there is a way to put a remote pressure monitor on it. It would be nice to be able to monitor it from insid the car. I figure that when I go boost, I'll add that to the wish list of things to monitor on my HUD.
 
A year has gone by since my Accusump rebuild and I have learned that standard Teflon does not hold up to oil. :redface: My system is leaking EVERYWHERE and I have not been driving the NSX due to obvious reasons.

So I went into Home Depot to look for liquid PTFE, even though the instuctions for the Accusump clearly warn against this! As I was walking away with my liquid PTFE I noticed a bin of assorted tape and rummaged through it in an effort to decipher why there were different colors of packaging. Low and behold, they make a tape designed for oil and gas! :eek: The things you don't realize until you do. :rolleyes:

So I am now back on a mission to re-rebuild my Accusump and hope that I've finally found the missing link!
 
Have you considered a thread locker from Loctite or equivalent? Not the thread sealant as they usually contain PTFE, but the normal thread locker (not the red!) They are resistant to oil/gas.

It's the same potential contaminant scenario as liquid PTFE, but it certainly would fix the leaking.

Dave
 
Back
Top