Just wondering if there are any valve trombone players out there. I've begun to play this on Motown and Jazz tunes, but have a problem with the pistons sticking. I used a medium grade oil and have now switched to a lighter grade, but still with the problem. The horn is new and I'm considering sending it back for a replacement. It's a Durand, which is a cheaper model than say a Jupiter. Thanks. Just wondering if there are any valve trombone players out there. I've begun to play this on Motown and Jazz tunes, but have a problem with the pistons sticking. I used a medium grade oil and have now switched to a lighter grade, but still with the problem. The horn is new and I'm considering sending it back for a replacement. It's a Durand, which is a cheaper model than say a Jupiter. Thanks.