TargetTalk

Has anyone repaired the pressure release valve on a Daisy cylinder? Thank you.

I assume you mean for an 888/887 type cylinder
If you mean torn down & replaced internal parts ... no

I have had a few leak over the years and normally this is caused by some dust, dirt, lint, a speck of that white foam packaging.
I have been able to get all but one holding pressure again by emptying the cylinder and then holding it so the valve is up, putting about 5-6 drops of the Beemans MP5 airgun oil in the recess and depressing the plunger a few times to "rinse" off the internal seat ... partially fill, empty, and redo this a few times.

Also, always store the cylinder with some pressure to keep the seals seated. I don't shoot our guns till the cylinders are empty ... only down to about 440 grams total weight. Use the yellow caps that come with the cylinder if it is stored out of the gun, else keep it with the rifle screwed into the gun a turn or two just to keep crud out of the valve area of the gun too. (not far enough to engage the o-ring ... just enough so it does not fall out)

After you get it holding pressure fill and then holding the tank with the valve down, drain the tank slowly to get any excess oil out of the cylinder (or when empty, remove the burst disk at the other end of the tank and drain & "air out"

When you do this, some residual oil will be in the tank and go thru the action & barrel, so it may take about 100 shots or so to get the rifle firing it's best groups again .... good time to fire some of the felts thru it too.

If none of this works, send it back to Daisy for repair/replacement ... they are good about that

I was actually refering to the burst disk. Is there any way to repair it? Thank you, David.

Easy .... go to Walmart and go back to their sporting good section where they have paintball gear

Just pick up a burst disk there ... while you are there grab a pack of o-rings as you'll eventually need a few of those too