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Discussion Starter · #1 ·
I have a Manitou SPV shock, and if I compress it while I have the shock pump attached with the pressure gauge, I loose 10-30 PSI for each compression.

Would this method tell anything about the condition of my shock?

I feel the shock is rather anonymous when riding, and it has a huge sag that carnt be adjusted away, even when pumped to max pressure.
 

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dbmnk said:
I have a Manitou SPV shock, and if I compress it while I have the shock pump attached with the pressure gauge, I loose 10-30 PSI for each compression.

Would this method tell anything about the condition of my shock?

I feel the shock is rather anonymous when riding, and it has a huge sag that carnt be adjusted away, even when pumped to max pressure.
If you have to pump it up more than once a month it needs servicing for the leak...

I have a Fox RP23 with those symptoms I would have air chanber leak into the negative air chamber, a seal kit and 15 mins would fix it.
 

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That doesn't sound like a good way to test your shock, because your valve is open. when you compress it, the air you lose might be just going through the valve to the pump.
Pump it up to max and ride it, then connect your pump and check pressure. It should be close to the same.
If you can't get rid of excessive sag, that sounds like a leak. You probably need a new seal kit. I don't know about Manitou, but with my Fox float the kit only costs a few bucks and I do it myself.
 

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Fixin' shocks Day & Night
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Yes, you are loosing air. If you pump your shock to a pressure then compress it and it looses air then you have a leak. It could be just some seals and fresh lube.. When was the last rebuild?

Tim
 

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Discussion Starter · #5 ·
thanks for the good advice, I'll test out with reconnecting.

I don't now when it was rebuild, but I recently got it with a used bike bought at LPS, so I assumed they would make sure the shock was in fine condition.

Now I brought the bike to a foreign country, so re-service is not easy.

Annoying stuff.
 

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dbmnk said:
thanks for the good advice, I'll test out with reconnecting.

I don't now when it was rebuild, but I recently got it with a used bike bought at LPS, so I assumed they would make sure the shock was in fine condition.

Now I brought the bike to a foreign country, so re-service is not easy.

Annoying stuff.
Never assume they went through a shock inspection or rebuild on a used bike. I learned when I worked at shops, If the suspension isn't leaking oil all over then it's fine. Needless to say that is why myself and many other's have made shock rebuilding into an industry. That being said, you are out of country but not out of luck! Check to see if any local shop has a Manitou account and order a seal kit for your shock. You will need the year the shock was made and the Manufacturer and the style of the shock ( the name i.e. 2006 Manitou swinger 4way). If your local shop cannot help then go online there are plenty of places a seal kit can be found. Buy a seal kit and as many have said here it's easy to rebuild. Same basic steps as the FOX Float or RP series shocks. If you need more help let me know.

Tim
 

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dbmnk said:
...while I have the shock pump attached with the pressure gauge, I loose 10-30 PSI for each compression.
I agree with the others who have said this isn't the best way to check for a leak. This could just as easily be a leak in the pump or the connector.

If your shock is losing 10 PSI per compression **without** the pump attached, you'd know it pretty quickly.

Best indication to set your shock to an amount of appropriate sag, and if it's sagging more at the end of the ride, you've got some air loss that needs dealing with.
 

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Discussion Starter · #8 ·
well apparently not. I used to be really satisfied with that LPS, but this time the bike I got had so many small flaws - most of them only cosmetic or easily adjusted, but the shocks is unacceptable I think.

But Tim you might be able to shoot me in the right direction - do you know what kind of shock this is?



 

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You need to adjust your preload or get a new coil, not change the pressure. That pressure is for compression valving adjustment. It will affect sag a bit, but not much. As for it losing pressure, its volume is tiny, just filling the shock pump hose will come close to emptying the chamber.
 

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Discussion Starter · #10 ·
Scotth72 said:
You need to adjust your preload or get a new coil,
the rebound, turned to either end of the adjustment doesn't change any sag. :confused:

regarding measuring the air loss, my shock pump doesn't read the pressure when re-attached, and my handheld pressure gauge doesn't fit.:mad:
 

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dbmnk said:
the rebound, turned to either end of the adjustment doesn't change any sag. :confused:

regarding measuring the air loss, my shock pump doesn't read the pressure when re-attached, and my handheld pressure gauge doesn't fit.:mad:
Rebound doesn't affect sag, the spring rating and a preload adjustment (the ring that compresses the spring) affect sag.

It sounds like the air chamber is empty when you re-attach the shock pump. Like others have said, just attach the pump to set pressure; test for leaks without pump attached. Could just be your technique in attaching the pump or there could be something wrong with your shock pump, too...
 

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dbmnk said:
the rebound, turned to either end of the adjustment doesn't change any sag. :confused:

regarding measuring the air loss, my shock pump doesn't read the pressure when re-attached, and my handheld pressure gauge doesn't fit.:mad:
By preload, he means you need to turn that knurled ring that is at the top of your spring (clockwise?).
That will compress the spring so that it is in a partially compressed state even before you sit on the bike, making further compression of the spring more difficult. That will reduce your sag. As was mentioned, adding air isn't going to effect your sag.
As you can see, there is probably an inch or 2 of threads that will allow significant precompression of your spring. If you screw it all the way down and it is still too soft, then you need to buy a stronger spring.
 

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Now that I look at the picture, it looks like there is a fair amount of preload on the spring already. Crank it the rest of the way down and see how it feels. You might need a heavier spring.
 

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smilinsteve said:
Now that I look at the picture, it looks like there is a fair amount of preload on the spring already. Crank it the rest of the way down and see how it feels. You might need a heavier spring.
NO! The free length of the spring is not determinable by looking at the picture, or how much preload's been applied. Just because there are threads available doesn't mean you should preload the spring to use them all. A few mm's is usually all that's recommended. Use the manual for manufacturer's max recommendation.
 

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That shock is a swinger 3way, just unbolt it and submerge in some water, sink, bathtub, a bucket, anything.When too much air enters the oil volume side it will reset the IFP and all the IFp volume is lost, resulting in such a small volume to pressurize that the pressure is usually lost before the pumphead can be removed.
 

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Discussion Starter · #16 ·
DRAKETHOMAS said:
When too much air enters the oil volume side it will reset the IFP and all the IFp volume is lost, resulting in such a small volume to pressurize that the pressure is usually lost before the pumphead can be removed.
can you please elaborate a bit on this?
How do I check for it, and what is the solution?
 

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Attach pump, pressurize to 100 psi, and leave it alone for 15 minutes, if all air is lost then submerge in tank of water and verify with bubbles in water.If indeed there is loss in 15minutes then you might have a leak in the oil volume side of the Internal Floating piston. If this is the case you would probably have a mild oil leakage as well.Service needs to be done once a year.A full service as well.
 
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