Disc Brake Hydraulic Actuator pump failure?

Randu wrote:
Road test excellent. Adjusted the boost down to level 1 from level 3. Very nice smooth controlled stop. Randu

Great!

Road test excellent. Adjusted the boost down to level 1 from level 3. Very nice smooth controlled stop. Randu

Glad it is fixed. Let us know how the road test goes.

Round Topper wrote:
There is a recall on some of the Carlisle brake actuators. Check with Carlisle and make sure it doesn't apply to your model/serial number.

From what I know our timeframe was not effected. This was the first time I have heard of this model having problems, and they really were not Carlisle problems after all.

There is a recall on some of the Carlisle brake actuators. Check with Carlisle and make sure it doesn't apply to your model/serial number.

Randu wrote:
stsmark got me thinking air lock when he asked about bleeding at the pump.

I spent a few hours rerouting a heat duct, water line and a gas line to get good access to the pump. Actually removed pump and dumped out old fluid and got some brown crud flakes. Mounted in a different position and then filled reservoir and bleed at pump. Ton of air but expected that since I had dumped old fluid. Did notice pitch of pump was back to normal sound. Went to wheels and got air out of each caliper.

Hook 47 is right about the reservoir capacity being small. Had to start over one time as it ran out. Pump now changes pitch and goes to full pressure "dead headed" sound almost instantly. Not slow ramp up of pitch. Won't get a chance to test drive around until later in the week but real confident that its fixed.

Root cause conclusion:
I think fluid got too low as the pads wore. I thought fluid was only low but I really could not see in original mounting position. I'm now thinking that fluid was out and nothing for the pump to push. Pump got air locked so nothing was happening when I added additional fluid yesterday.
Thanks for all comments , Randu

I would recommend bleeding again after you take it out and bring it home.

I feel better now that yours is fine. You are the first person I have heard of with a problem. Thankfully it was not the controllers fault.

That sounds like a reasonable conclusion. Let us know if that fixed it.

stsmark got me thinking air lock when he asked about bleeding at the pump.

I spent a few hours rerouting a heat duct, water line and a gas line to get good access to the pump. Actually removed pump and dumped out old fluid and got some brown crud flakes. Mounted in a different position and then filled reservoir and bleed at pump. Ton of air but expected that since I had dumped old fluid. Did notice pitch of pump was back to normal sound. Went to wheels and got air out of each caliper.

Hook 47 is right about the reservoir capacity being small. Had to start over one time as it ran out. Pump now changes pitch and goes to full pressure "dead headed" sound almost instantly. Not slow ramp up of pitch. Won't get a chance to test drive around until later in the week but real confident that its fixed.

Root cause conclusion:
I think fluid got too low as the pads wore. I thought fluid was only low but I really could not see in original mounting position. I'm now thinking that fluid was out and nothing for the pump to push. Pump got air locked so nothing was happening when I added additional fluid yesterday.
Thanks for all comments , Randu

When I bled my brakes on my 07 MS 36TK3 I learned that it takes very little time to empty the reservoir. Not much capacity. I will assume that you topped of the reservoir and then tried to bleed at the farthest caliper? Have you tried all calipers to eliminate the possibility of a blockage in one? With the fluid topped off, cap closed, and brake controller applied do all the calipers stop the wheels from turning by hand? Good luck and let us know what you find out.

When I posted a concern about teething issues with pumps in the other disc brake thread people jumped on me! And here it is a teething thread!

Glad I made the decession that I did. Chris