1983 GL1100 rear shock issue

[jaybird33]

Hey all! So I rebuilt rear the air shocks on my '83 Interstate. I replaced everything but the springs. They are a little soft but that's fine by me just wanted them to hold air again lol. Before the rebuild I hit a small pothole and something gave way. I noticed when I got off the bike that the right side gave way much easier than the left, and all the air pressure was out. I took them both off, replaces all the seals, bushings, and the o-rings in the airlines. Cleaned them up and put fresh fluid in them. Yesterday I finally got everything back together and filled them with air to 57 psi as suggested in the manual. It is possible a may have overfilled them with air at first because I didn't realize how fast they fill up and I used my compressor. Almost knocked the bike over because it jumped up so quick. My air gauge reads to 50 and it was over than so a let a tiny bit out and got it to just over 50 psi. About 5 minutes later I heard a pop and hiss as the left shock spewed oil on the ground . Here's my questions:

-Why was the right shock much softer than the left. Even after the rebuild before I put air in.
-What do you think went wrong? All the guts except the springs were replaced. It it likely I just filled it too fast and blew it?
-Why did it take 5 minutes to give way?
-Should I rebuild the one shock again and use less pressure?
-With older softer springs, and less support, does that put more pressure in the shock?
-I'd like to keep the original air shocks especially with new parts in them, but am I better off just getting replacement spring shocks?

Thanks for any help you can offer I attached a pic of one of them after rebuild for reference.
Jay

[WingAdmin]

"softness" is generally from two things. First is tired springs - and you can test this by measuring the amount of sag - although harder to do with two shocks on the bike. If you unbolt one of the shocks, then let the weight of the bike onto the wheel, measure the amount of travel between fully extended to compressed with the bike weight on it. Then do it again with just the other shock mounted. They should be relatively close. If not, you've got one spring that's worn more than the others.

The other cause of "soft" is fluid - viscosity of fluid combined with valving. Valve orifices that are not closing properly, leaks letting fluid past, something that isn't restricting the movement of fluid properly.

Lastly, it's entirely possible you blew a seal of something filling with a high volume compressor. It's generally advised to fill suspension shocks with a hand-operated bicycle pump - it doesn't take much to overpressurize them, as you discovered.

[jaybird33]

"softness" is generally from two things. First is tired springs - and you can test this by measuring the amount of sag - although harder to do with two shocks on the bike. If you unbolt one of the shocks, then let the weight of the bike onto the wheel, measure the amount of travel between fully extended to compressed with the bike weight on it. Then do it again with just the other shock mounted. They should be relatively close. If not, you've got one spring that's worn more than the others.

The other cause of "soft" is fluid - viscosity of fluid combined with valving. Valve orifices that are not closing properly, leaks letting fluid past, something that isn't restricting the movement of fluid properly.

Lastly, it's entirely possible you blew a seal of something filling with a high volume compressor. It's generally advised to fill suspension shocks with a hand-operated bicycle pump - it doesn't take much to overpressurize them, as you discovered.

Yeah I could understand fluid leakage prior to the rebuild, but not after. Maybe the spring is just more tired than the other, although I'd think they'd wear about the same. The seals are brand new so I'm hoping I can take the one apart and put it back together and it will still hold. Ill be more careful inflating. I just thought it weird that it took a few minutes to "blow".

[LAB3]

It takes my mini HF 12v air compressor about 10 seconds to go from 10psi to 50psi in my shocks, my bet is that using a standard high volume compressor blew the seals out.

[jaybird33]

Yeah Im just hoping I didn't ruin the brand new seal. It took a few minutes to actually leak though.

[LAB3]

Yeah Im just hoping I didn't ruin the brand new seal. It took a few minutes to actually leak though.

Keep your stick on the ice. Remember, we're all in this together!

"I'm a Seal, and I can be changed, if I have to, I guess"

[Limpy45]

Did you get the snap ring totally installed into the groove? I would guess that the air pressure blew it and the seal back out again. The are stinkers to re-install some times. I just did the air shocks on my 1500. Different brand, but use same seals and very similar if not identical shocks. I would check that. As to spring inside that holds load, you need to totally dis-assemble the shocks using a spring compressor like
the one from Progressive suspension. Then there are O rings seals around the top also, plus springs inside the 'can'.

[jaybird33]

Did you get the snap ring totally installed into the groove? I would guess that the air pressure blew it and the seal back out again. The are stinkers to re-install some times. I just did the air shocks on my 1500. Different brand, but use same seals and very similar if not identical shocks. I would check that. As to spring inside that holds load, you need to totally dis-assemble the shocks using a spring compressor like
the one from Progressive suspension. Then there are O rings seals around the top also, plus springs inside the 'can'.

I thought I got the ring in but who knows lol. I have seen the procedure to change out the springs, but I'm fine with the ones in them. Just need them to hold air and oil lol.

[PhotoDoctor]

Also, isn't 50psi at the upper limit of pressure.

The 1983, I believe can run with or without air - unlike the earlier 1100's that were dangerous without air to the point that Honda put a warning light in the Speedometer gauge. In 1983 that same light is used as a 5th gear indicator as the shocks were improved for safety.

[jaybird33]

Also, isn't 50psi at the upper limit of pressure.

The 1983, I believe can run with or without air - unlike the earlier 1100's that were dangerous without air to the point that Honda put a warning light in the Speedometer gauge. In 1983 that same light is used as a 5th gear indicator as the shocks were improved for safety.

The manual says 57 psi. I partially took the shock apart last week and the snap ring, seal, and washers had all blown out. The seal is brand new so I reinstalled everything and refilled the fluid. I put 50 psi in with a bike pump. It's still on the center stand but so far it's held. Going to test it later today hopefully. I am hoping it was just me filling it way too fast with the compressor. With no air in them, the right shock seems way softer than the left. I didnt want to take it fully apart, but what are the odds the spring is broken in the "soft" one?

[PhotoDoctor]

The sticker on my bike says 0 to 57 psi, so you could run it with less pressure if you wanted to seat the seal in. It's hard to see so I circled it in yellow.

[jaybird33]

Well I took it all apart, put the blown seal back in, and put it all back together. Filled it slowly with a bike pump and it seems to be holding. So far so good!

[Jodie83gl]

Also, isn't 50psi at the upper limit of pressure.

The 1983, I believe can run with or without air - unlike the earlier 1100's that were dangerous without air to the point that Honda put a warning light in the Speedometer gauge. In 1983 that same light is used as a 5th gear indicator as the shocks were improved for safety.

Hey Photodoc I read your post I have a 83 interstate. I don't have a 5th gear light but would love to have it. Possibly my light is burnt maybe? Where on the bike should this be located?
Jodie

[PhotoDoctor]

The 5th gear light is on the lower right side of the speedometer - It's marked "overdrive" on mine. (On earlier 1100's the same light location was used for low air pressure in the rear shocks .... at least on the Interstate models)