XK8 / XKR ( X100 ) 1996 - 2006

Convertible top latch hydraulic problem

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  #521  
Old 03-26-2013, 08:12 AM
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I would say that the roof micro switches in the ram are working. That switch sends the signal to tell the latch to work and it is clear that the latch is working when it closes. Just doing it early. I would suggest looking at your fluid level first and check the petcock completely closed. If all of that is good then use a dry lube on the joints of the roof and be sure that they are clear of all debris. When spraying the joints protect the area from over spray. When you reset the system did you do it when the roof system was in a normal or abnormal status? I like to reset when the roof is open and the latch is closed.
 
  #522  
Old 03-26-2013, 08:13 AM
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Originally Posted by steveinfrance
That's probably a stuck latch 'ready to lock' microswitch (item 6 page 6 in the attached)
This is in series with the lift ram 'top raised' microswitch. Both need to be closed before the latch will move to the closed position.
If you download JTIS you'll get the wire colour codes and BPM pinouts to test this, or simply pull off all the trim to get to the latch switches.
You MIGHT get away with the following
Open the pump petcock
Use the Allen Key to open the latch
The top should pop into closed position
Use the Allen key to close the latch
Close the petcock
Then use the switch to open the top.
Lubricate the lock mechanism, open the petcock and cycle the latch many times with the Allen key
Close the petcock and pray while closing the top.
Thanks Steve - it looks like the system is just frozen - that's why I tried the battery reset - worked the first time. I tried the petcock and Allen wrench but the hood doesn't come down that last quarter inch to lock - seems like the rams are fully pressurized. I had the latch rebuilt per Gus's suggestion at Top Hydraulics but perhaps should have had the rams rebuilt too. Will start taking the back apart to get to the rams this weekend while the weather is still in the 70's! I will look at the micro switches also.
 
  #523  
Old 03-26-2013, 08:14 AM
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The relief valve is only in the system for the roof latch. The rams do not see it.
 
  #524  
Old 03-26-2013, 08:17 AM
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Originally Posted by Gus
The relief valve is only in the system for the roof latch. The rams do not see it.
Gus, mine's wired exactly as yours. If I back off the set screw the lift rams stop half way up.

Kymentor,
If you manually retract the latch can you get someone to lean on the top while you lock it.
There's a fair chance that, once properly closed, the BPM will get its act together.
 

Last edited by steveinfrance; 03-26-2013 at 08:21 AM.
  #525  
Old 03-26-2013, 08:18 AM
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Originally Posted by Gus
I would say that the roof micro switches in the ram are working. That switch sends the signal to tell the latch to work and it is clear that the latch is working when it closes. Just doing it early. I would suggest looking at your fluid level first and check the petcock completely closed. If all of that is good then use a dry lube on the joints of the roof and be sure that they are clear of all debris. When spraying the joints protect the area from over spray. When you reset the system did you do it when the roof system was in a normal or abnormal status? I like to reset when the roof is open and the latch is closed.
Hi Gus - the fluid level is right up to the line and I have turned the petcock a few times from stop to stop. I did use some dry carbon on the latch ( even though when I installed it it was very smooth as it had been rebuilt by top hydraulics). I reset the system ( touched the battery terminals for 20 secs) when in abnormal mode to get any residuals to discharge.
 
  #526  
Old 03-26-2013, 08:22 AM
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Just repeating what Walt told me when he designed the valve.

Originally Posted by steveinfrance
Gus, mine's wired exactly as yours. If I back off the set screw the lift rams stop half way up.

Kymentor,
If you manually retract the latch can you get someone to lean on the top while you lock it.
There's a fair chance that, once properly closed, the BPM will get its act together.
 
  #527  
Old 03-26-2013, 08:32 AM
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Check your PM

Originally Posted by kvmentor
Hi Gus - the fluid level is right up to the line and I have turned the petcock a few times from stop to stop. I did use some dry carbon on the latch ( even though when I installed it it was very smooth as it had been rebuilt by top hydraulics). I reset the system ( touched the battery terminals for 20 secs) when in abnormal mode to get any residuals to discharge.
 
  #528  
Old 03-26-2013, 08:42 AM
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Originally Posted by Gus
Just repeating what Walt told me when he designed the valve.
All I can say is that's how I set the working pressure on mine. It came preset to whatever it should be but I was able to back it off even more until the top just moved normally with no hesitation.
 
  #529  
Old 03-26-2013, 08:50 AM
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I think it's this way.

In the neighborhood that the LSI valve is normally set, ~ 1000 PSI, it does not come into play as the top is being raised or lowered, because the pressure then is ~ 800 PSI or less (that number from memory, but it's for sure well under 1000 PSI).

That's probably what was meant by "the rams don't see it". But it is in the circuit all the time, so if it's set to a low enough pressure limit then the rams will see it.
 
  #530  
Old 03-26-2013, 09:02 AM
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It was suggested by Walt that port that the PRV was installed was for the latch and not the lifts. The pump has two distinctive functions operating two valves and two ports and they do not interfere with each other. I have a pump that I will check this to verify but I have not reason to doubt Walt.
 
  #531  
Old 03-26-2013, 09:37 AM
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Odd result then.
Whatever port you and he used when measuring system pressure certainly gave both lift and latch pressures.
 
  #532  
Old 03-26-2013, 09:41 AM
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This much I can say from 1st hand experience. The port on the pump body where the valve is attached ... that port sees the pressure that the pump is making, no matter whether it is directed to rams or latch or both, no matter whether the pump is running in one direction or the other.
 
  #533  
Old 03-26-2013, 09:49 AM
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We will see! I could be wrong and I do not have a problem with that. I just want to provide Accurate info.
 
  #534  
Old 03-26-2013, 09:51 AM
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Of course. I think it would be good to take it as a given that we all want to provide accurate information.
 
  #535  
Old 03-26-2013, 05:34 PM
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The PRV see the pressure to the rams as well so I stand to be corrected. However, adjusting it takes it out of the factory settings and that will affect the pressure to the latch as well. The extreme is that you could cancel all the good the valve was designed to do.

The rams are going to complete extension and we are seeing this because the latch system is activated by the ram switch so adjusting the PRV is not a fix for this but timing is. In fact we are seeing the latch close without grabbing the roof.
 
  #536  
Old 03-27-2013, 03:13 AM
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He has two problems
1. A slow moving top which could be low pressure from the PRV.
2. As you say, Gus, mis-timing of the latch mechanism.
In my opinion that is due to a permanently closed ready to latch switch.
As soon as the lift ram gets near to the end of travel and actuates the top up switch (in series with the RTL switch) the BPM thinks the claw's in the latch and closes it.
 
  #537  
Old 03-27-2013, 08:02 AM
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As of last night lubrication and reset fixed the problem.
 
  #538  
Old 03-27-2013, 08:07 AM
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Sticking latch switch then!
 
  #539  
Old 03-27-2013, 10:07 AM
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No, the latch was not the problem remember it was faster than the roof operation. Lubrication was applied to the roof related joints and lifts.
 
  #540  
Old 03-27-2013, 10:31 AM
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Gus, you know much more about this than I do but the latch CANNOT operate until the 'Ready to Latch' microswitch closes.
This can only close when the hook on the top pushes on the latch claw and actuates the switch.
It isn't a timing thing, the BPM needs to see both 'Top Raised' and 'Ready to Latch' before actuating the latch mechanism.
 


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