Shock was empty but no leak?

[CantWin1]

Hi,

 

2005 Venture, picked up in March this year, advertised as needing a shock, and nearing 100k miles, but at a good price. Talked to the guy on the phone, big guy...maybe twice my size, so I figure maybe it's still rideable at my weight of 160. Sure enough, it appeared the shock was blown as even with me on it it rode like a '73 Buick with eight of your buddies in the seats and the rest in the trunk headed for the $2 a car drive-in. And the bottom of the shock had some semi wet residue on it.

 

After reading a bunch of threads about shocks I recalled having read something about tilting the bike and allowing fluid to run out of the shock to quiet a 'groaning' seal. Well when I bought the bike I was told it had been laid down on the highway in traffic a couple years earlier, don't know how long it was laid over. So I got to thinking the other night...maybe most of the oil ran out of the shock.

 

In haste without doing any digging as to what to put in it other than a note I had read about someone putting 20W shock oil and some Automatic Tranny fluid...I wound up with all I could find at a Pep Boys at 8pm...A quart of ATF. Figured I'd squirt an ounce or two into the shock, see how bad it leaked and go from there. It took the first couple and there was a noticeable 'feel' of a difference bouncing up and down while in the driveway. So I fed it a couple more shots, even better! Couple more and there was a real difference. All the time checking underneath expecting a puddle. Took it for a quick spin around the block and it was still a bit 'rocking horse' feeling if I tried to make it bounce. Had never checked the air in it, thinking if the oil leaked out how could it hold any air!?

 

Put about 50# of air in it and it felt way to stiff, so I dropped it down to about 35#. That was Monday evening. Rode to work and back past couple of days, about 40 miles total, hitting every rough spot and little whoop ti do I normally avoid and not a single drop of oil has shown up under it. In addition to this my 'nose diving' at stops has been reduced by about 80% which is huge when you're short legged and that nose diving really screws up your stopping stability and confidence.

 

I'll be putting some miles on it this weekend, going on a 600 mile round trip run to Vegas. So we'll see how it holds up.

 

Any thoughts as to why it wouldn't be leaking now if it had in the past? Did the ATF just swell the seals and they'll rot away now? Should I take it off and drain it so I can get the correct measured amount of fluid put in? (Read somewhere, but only 1 post, that there's roughly 7.5 oz of fluid.) What is the proper fluid to put in it?

[Pegasus1300]

You know, if its working ride it till it stops working. If it really lost the fluid from being laid down,then you should be able to take the shock off the bike and dump the new fluid you put in, out and when empty add the "correct mixture and amount".At the price of a new shock either OEM or after market its worth a try.What I want to know is why a bad rear shock causes you to nose dive when you brake?This sounds like a front end problem to me.At 7 years old and 100k miles I would be looking a replacing the front springs/fork oil and maybe a bushing rebuild.What air pressure are you running in the front forks?

[Gary N.]

I presume you have put oil into the air valve. This won't replace the oil that was lost in the shock as it is a sealed unit. All you did was add some oil into the air bladder. Some guys have done this in the past to help rid the bike of the grown or squeak that the shock sometimes gets. All the air bladder is for is to add stiffness for extra load carrying. The oil in the shock is to help control rebound so you don't get a bouncy ride. If you have indeed lost the shock oil you would see a mess under the bike.

[CantWin1]

The nose diving I guess is better explained as a rocking horse type action when coming to a stop, slow down, let off the brakes a bit and the back would sink, brake and it would rock forward, ease off at near a dead stop and sink in the back again.

 

The 'oil in the air bladder' is what has me confused. I've seen several posts about turning the shock upside down to drain the oil. If the air valve only accesses an air bladder then there should be no oil drain out, correct? I've been trying to figure out how people can have a leaky shock that will still hold air. A separate air bladder would explain this, but then it makes no sense that you could drain and refill the oil thru the air valve.

 

When I pulled the valve from the air inlet no air came out. So it has been running on 0. How does a good (or bad) shock feel with no air at all in it???

[Freebird]

Can you link to some of those posts about people draining the oil and re-filling because to be honest, I've never heard of anybody doing that. There are many instances of the shocks going bad (leaking oil) but still holding air. They are certainly a separate chamber. It is impossible to drain and replace the oil through the air valve. I don't remember those posts of anybody doing that.

[Hotrod]

Over on the Delphi Royal Star Venture and Tour Deluxe forum there was a discussion on doing this.It was titled(Regular Fork oil changes) under Tech talk.The poster talked about replacing the fork oil and the rear shock oil by removing the rear shock and turning upside down and draining over night.He replaced the oil with 20 wt. fork oil(44 ml).You can search the threads and the thread # is 12767.1.I have not tried this, but the poster said he has changed his 3 or 4 times and has almost 150,000 miles on his shock with no failure.