DUH (brake problem)

[Stretch44875]

One of those days...

When I picked up the M108, it had some broken brake lines. Replaced the brake lines, bleed the brakes. The brakes would come on, but not release. Figured the master cylinder return port was plugged.

So the other day, I replaced the master cylinder. It was leaking fluid out the front also. Get it all done, bleed the brakes, and I STILL have the same problem. So now I'm thinking airpac problem.

Start to take the airpac out, and I look up and see a solinod on the brake line. I think, Hmm, that's the mico-lock. Wait a minute, I wouldn't be that dumb to have the micro-lock on, would I? (for those that might not know, a micro-lock holds the brake line pressure to lock the brakes) Turns out, yes I would be that dumb. My mico is an on-off switch on the dash, and it was on. Turn it off, hook the airpac back up, and I have brakes!

another fine day wrenching....

Dennis

 

[Pinkie]

There were also some very few m715s that had the micro lock on the dash. They were usually the maintenance trucks with welder and gensets driven by the PTO.

 

[Recovry4x4]

They are usually a momentary on switch in which the line pressure holds it shut. Not sure how long it will last under constant voltage. FYI

 

[Stretch44875]

Well, mine was on for about 8 months. I think it will work under constant voltage.