Replacing the Jägermobile Water Pump Again!

[southernstar]

Pedro on Pedro's board has over 200,000 miles on his original pump and he believes that some of the early pump failures are due to people occasionally opening the coolant reservoir cap when the engine is still hot. It is, of course, supposed to be a sealed coolant system and he believes that bubbling when the cap is removed can lead to air locks (as well as reduced coolant due to vapour) that ultimately cause failure of the impeller. His rule is to never remove the cap; if coolant is down, there is already an issue.

Brad

[Perfectlap]

Originally Posted by southernstar

Pedro on Pedro's board has over 200,000 miles on his original pump and he believes that some of the early pump failures are due to people occasionally opening the coolant reservoir cap when the engine is still hot. It is, of course, supposed to be a sealed coolant system and he believes that bubbling when the cap is removed can lead to air locks (as well as reduced coolant due to vapour) that ultimately cause failure of the impeller. His rule is to never remove the cap; if coolant is down, there is already an issue.

Brad

Good to know.
Pedro also pointed out that flushing the coolant needs to be done precisely, if any air is in the system the original and probably brittle coolant tank with split within a year or so.
Might have been coincidence but that's exactly what happened to me. I ended up spending $1,000 on the flush and new tank within 12 months of each other, I probably should have done the watermpump then too.

[jaykay]

Is everyone vacum bleeding their cooling systems after pump changes? Without vacum system bleeding you can spend a whole day burping the system ...and you are never really sure that you have managed get rid of all air bubbles. Air in the system would be a potential cavitation mechanism. If this cavitation occurs near the impeller blades of the pump it can cause failure of the blade. Cavitation can cause failures of impellers even if they are metal.

It is my guess that cyclic stresses from pump cavitation are giving rise to pump impeller blade failures. In addition to this you have age related weakening of the composite material as noted by J. Raby at flat six

If pump your has failed you may be eligible for a free replacement as far I have heard. I only see evidence of seepage on mine so this won't be enough to get a free one. I have an OEM one ready to go in, hopefully it won't let me down....oh yes make sure you change the coolant tank res. cap