71/72 front seals blowing out: OEM vs. aftermarket pumps

By Chris, Hale Marine · 40+ years rebuilding Velvet Drive and ZF transmissions

Short answer: Chris has never had a current Velvet Drive 71/72 pump blow its front seal: it has a guard and the seal is pressed in from the back. The aftermarket pumps without the guard are the ones popping seals.

71, 72 Series Velvet Pumps

What Chris sees

Aftermarket pump seals that you can almost push in by hand. That's how bad it's gotten.
A customer in Maine who put two seals in an aftermarket pump and still blew the front seal out.
In 40-plus years of doing this, Chris can't remember a front seal ever blowing out on the older pumps. It's a newer problem.

What causes it

Velvet Drive's newer pumps have a guard around the seal area, so the seal can't get pushed out. The aftermarket version doesn't have that guard. Chris thinks the seals themselves are part of it too. They're supposed to fit properly, but they're probably just a scosh off, and that's why they're popping out. As he put it, it's probably the quality of the seals we're getting nowadays.

Velvet Drive 71 & 72 Series Front seals blowing out !!

Replacing the seal

On the early pumps and the aftermarket version, you can pull the seal out with a hammer and screwdriver. On the new-style Velvet Drive pump with the guard, you have to take the pump off the transmission and drive the seal out through the pump toward the transmission side, so it comes out the back.

Velvet Drive pump assemble Viewer question about seal replacement.

Fix and prevention

The Velvet Drive pump with the guard costs more. But if you've had a front seal blow out, you're better off spending the money and buying the Velvet Drive pump. That's the one Chris prefers when it's available. If you just need the seal, we stock the 71-72 front seal ($12.50).

When to call

If your front seal has blown out more than once, call (804) 333-3677, Monday through Friday 9 to 3 Eastern, or email sales@halemarine.com.