ALB Pump problem

[JKLedbetter]

The ALB pump on the '89 started running continuously, until the ALB computer would shut it off and illuminate the ALB light on the dash.

The fluid level in the ALB reservoir looks normal, which would seem to rule out an external leak.

The two most likely possibilities I could think of were that the pump mechanism has failed (not the electric motor that drives it), or the solenoids in the modulator are letting fluid leak through.

Using my homemade tester I briefly activated one of the solenoids in the modulator and the fluid in the reservoir began to foam. I think this indicates that there was still some pressure in the accumulator, which rules out leaking solenoids, but I don't understand how air got into the system to cause foam.

I then ran the pump motor for several seconds, but the fluid in the reservoir did not drop, nor did the pump sound like it was building pressure.

I relieved the rest of the pressure with the T-wrench, though there wasn't much, not even enough to push fluid all the way up to the T-wrench reservoir.

I am leaning toward the pump being bad, but I don't understand the foam.

Can any of you help me understand the foam?

Do any of you have a pump to sell?

-Kennon